Skip to navigation bar Skip to breadcrumbs Skip to page content
clear place holder
Envelope icon E-mail Updates Teal square Text size:  a A A
Choose another version >>

Archived Final Evidence Summary

Other Supporting Document for Healthy Diet and Physical Activity: Counseling for CVD Prevention in Adults

Originally published on: August 14, 2014

This recommendation statement is currently archived and inactive. It should be used for historical purposes only. Click here for copyright and source information .

Disclaimer:Recommendations made by the USPSTF are independent of the U.S. government. They should not be construed as an official position of the Agency for Healthcare Research and Quality or the U.S. Department of Health and Human Services.

Archived: Preface

A Systematic Review for the U.S. Preventive Services Task Force

Release Date: December 2010


By Jennifer S. Lin, MD, MCR; Elizabeth O'Connor, PhD; Evelyn P. Whitlock, MD, MPH; and Tracy L. Beil, MS


The information in this report is intended to help clinicians, employers, policymakers, and others make informed decisions about the provision of health care services. This report is intended as a reference and not as a substitute for clinical judgment.

This report may be used, in whole or in part, as the basis for the development of clinical practice guidelines and other quality enhancement tools, or as a basis for reimbursement and coverage policies. AHRQ or U.S. Department of Health and Human Services endorsement of such derivative products may not be stated or implied.

This article was first published in Annals of Internal Medicine on December 7, 2010 (Annals of Internal Medicine 2010;153(11):736-750; www.annals.org). Select for copyright and source information.

Archived: Abstract

Background: Poor diet and lack of physical activity can worsen cardiovascular health, yet most Americans do not meet diet and physical activity recommendations.

Purpose: To assist the U.S. Preventive Services Task Force in updating its previous recommendations by systematically reviewing trials of physical activity or dietary counseling to prevent cardiovascular disease.

Data Sources: MEDLINE, PsycINFO, Cochrane Central Register of Controlled Trials (2001 to January 2010), experts, and existing systematic reviews.

Study Selection: Two investigators independently reviewed 13,562 abstracts and 481 articles against a set of a priori inclusion criteria and critically appraised each study by using design-specific quality criteria.

Data Extraction and Analysis: Data from 73 studies (109 articles) were abstracted by one reviewer and checked by a second reviewer. Random-effects meta-analyses were conducted for multiple intermediate health and behavioral outcomes.

Data Synthesis: Long-term observational follow-up of intensive sodium reduction counseling showed a decrease in the incidence of cardiovascular disease; however, other direct evidence for reduction in disease morbidity is lacking. High-intensity dietary counseling, with or without physical activity counseling, resulted in changes of -0.3 to -0.7 kg/m2 in body mass index (adiposity), -1.5 mm Hg (95% CI, -0.9 to -2.1 mm Hg) in systolic blood pressure, -0.7 mm Hg (CI, -0.6 to -0.9 mm Hg) in diastolic pressure, -0.17 mmol/L (CI, -0.09 to -0.25 mmol/L) (-6.56 mg/dL [CI, -3.47 to -9.65 mg/dL]) in total cholesterol level, and -0.13 mmol/L (CI, -0.06 to -0.21 mmol/L) (-5.02 mg/dL [CI, -2.32 to -8.11 mg/dL]) in low-density lipoprotein cholesterol level. Medium- and high-intensity counseling resulted in moderate to large changes in self-reported dietary and physical activity behaviors.

Limitation: Meta-analyses for some outcomes had large statistical heterogeneity or evidence for publication bias. Only 11 trials followed outcomes beyond 12 months.

Conclusion: Counseling to improve diet or increase physical activity changed health behaviors and was associated with small improvements in adiposity, blood pressure, and lipid levels.

Primary Funding Source: Agency for Healthcare Research and Quality.

Archived: Introduction

Diseases associated with physical inactivity and poor diet rank among the leading causes of illness and death in the United States1, 2 and are well-established determinants in many chronic diseases, including cardiovascular and cerebrovascular disease, hypertension, dyslipidemia, and type 2 diabetes1, 3-5. Although persons of all ages benefit from regular exercise5, Americans generally do not meet recommended levels of physical activity6, 7. Americans' diets are also drastically out of line with the generally accepted dietary recommendations published by many organizations, such as the U.S. Department of Health and Human Services8, 9.

In 2002 and 2003, the USPSTF concluded that evidence was insufficient to recommend for or against behavioral counseling in primary care settings to promote physical activity (I recommendation) or behavioral counseling to promote a healthful diet in unselected patients in primary care (I recommendation). We therefore performed this review to assist in the updating of these recommendations. This review combines counseling for both physical activity and dietary change with a focus on the prevention of cardiovascular disease in adults without known diabetes, hypertension, dyslipidemia, or coronary heart disease. To conduct this review, we developed an analytic framework with 4 key questions (Appendix Figure) that included the effect of dietary or physical activity counseling on health outcomes (key question 1), intermediate cardiovascular disease-related outcomes (key question 2), behavioral outcomes (key question 3), and harms of the counseling interventions (key question 4).

Archived: Methods

The full report10 provides a detailed description of our methods, including search strategies and excluded studies.

Data Sources and Searches

To identify literature published for each key question since the previous recommendations, we searched MEDLINE, PsycINFO, and the Cochrane Central Register of Controlled Trials from January 2001 to January 2010. We supplemented our searches with suggestions from experts and reference lists from other relevant publications, including the 2 previous USPSTF systematic reviews and 9 related existing reviews11-21.

Study Selection

Two investigators independently reviewed 13,562 abstracts and 481 articles against the specified inclusion criteria (Figure). We included trials with primary care-relevant counseling on physical activity (for example, aerobic activities, such as walking, cycling, or swimming, or resistance training) or healthful diet interventions (for example, appropriate calorie intake; increased intake of fruits and vegetables, whole grains, and fiber; balanced intake of fats; or decreased sodium). We excluded interventions primarily aimed at weight loss or those that provided controlled diets or supervised physical activity. Primary care-relevant counseling included interventions that were conducted in, judged feasible to be conducted in (such as phone or electronic interventions), or potentially referable from a primary care setting. Interventions had to be compared with usual care, a minimal intervention, or an attention-control group. We excluded interventions that targeted persons with known hypertension, hyperlipidemia, diabetes, or cardiovascular disease and trials in which more than 50% of the population had known heart disease or any one or a combination of these risk factors. We required a minimum follow-up of 6 months after randomization. A priori outcomes included true health outcomes (morbidity or mortality related to cardiovascular disease); intermediate outcomes and physiologic changes associated with health outcomes (blood pressure, lipid profile, fasting glucose level and glucose tolerance, and adiposity); and behavioral outcomes (any self-reported change in physical activity or dietary intake). We did not include cost-effectiveness or cost-related outcomes. For harms, we included any observational studies that reported serious cardiovascular harms, such as acute cardiac events during or immediately after physical activity.

Data Extraction and Quality Assessment

Articles that met our inclusion criteria were critically appraised by 2 reviewers using the USPSTF and National Institute for Health and Clinical Excellence design-specific quality criteria22. The reviewers were each blinded to the other's initial ratings, and discrepancies were resolved by consensus. Articles were rated as good, fair, or poor quality. Good-quality studies met all of the specified quality criteria, whereas fair-quality studies did not but had no fatal flaws in the design, execution, or reporting of the study. Poor-quality studies were excluded from this review.

For included studies, 1 investigator extracted data on study setting, populations, interventions, and prespecified outcomes into standardized evidence tables and a second investigator verified all extracted data.

Data Synthesis and Analysis

We conducted random-effects meta-analyses to estimate the effect size of counseling on all intermediate health outcomes and behavioral outcomes. We combined all trial with a given outcome and conducted separate analyses for each of the 3 intervention targets (physical activity, healthful diet, and combined) and, if applicable, for the specific dietary message (sodium reduction, focus on fruits and vegetables only, or general low-fat or heart-Healthful Dietary counseling). Analyses were stratified by estimated intervention intensity (low [≤30 minutes], medium [between 31 minutes and 6 hours of contact], or high [>6 hours of contact]). Trials were also categorized by population risk as being unselected or selected only on the basis of age; selected for suboptimal behavior (such as sedentary behavior or poor dietary intake); or selected for individual or population risk factors for increased incidence of cardiovascular disease (such as mildly elevated diastolic blood pressure or fasting glucose or serum lipid levels, obesity, or poverty or poor access to health care).

We assessed the presence of statistical heterogeneity among the studies by using standard chi-square tests and estimated the magnitude of heterogeneity by using the I2 statistic23. Tests of publication bias to determine whether the distribution of the effect sizes was symmetric with respect to the precision measure were performed by using funnel plots and the Egger linear regression method24, 25. Meta-regressions were performed on the basis of the random-effects models to examine the effect of 4 a priori variables of heterogeneity (intervention intensity, intervention target, study population risk, and recruitment method [volunteer vs. study-identified]) on effect size. To interpret effect sizes of standardized mean differences, we used the Cohen d statistic, in which an effect size of 0.2 to 0.3 generally represents a small effect; 0.5, a moderate effect; and 0.8, a large effect26.

All analyses were performed by using Stata, version 10.0 (StataCorp, College Station, Texas).

Role of the Funding Source

We worked with 4 USPSTF liaisons at key points throughout the review process to develop and refine the scope and resolve other issues. The Agency for Healthcare Research and Quality funded this research under a contract to support the USPSTF. The funding source had no role in study selection, quality assessment, or synthesis, although they provided project oversight, reviewed the draft evidence synthesis, and assisted in external review of the draft evidence synthesis.

Archived: Results

We identified 66 trials that reported the effects of counseling for physical activity, healthful diet, or both. Thirty trials27-71, comprising 15,265 patients, tested the effect of counseling persons to increase physical activity, and 26 of these (14,172 patients) were included in our meta-analyses27-29, 31, 33, 35-37, 42, 45, 47, 48, 50, 51, 53-57, 59, 61, 63-65, 67, 69, 70. Twenty-five trials29, 30, 37, 38, 42, 43, 48, 72-103, comprising 71,267 patients, tested the effect of counseling persons to eat a healthful diet; 24 of these studies (70,969 patients) were included in our meta-analyses37, 42, 48, 72-78, 81, 82, 85-93, 96, 99, 103. Seventeen trials42-44, 76, 104-125, comprising 5105 patients, examined the effects of counseling persons for both physical activity and healthful diet; we included 15 of these (4475 patients) in our meta-analyses42, 76, 104, 106, 108, 111, 113-118, 121, 124, 125. Some trials were not included in our meta-analyses because they did not provide necessary data; for example, some reported results only in figures without providing group means and others did not provide SEs or SDs. In addition, we identified 7 studies126-132, comprising 4354 patients, that addressed the harms of physical activity. The tables in the Supplement (available at www.annals.org) provide study details for counseling trials.

Of the 66 counseling trials, only 13 were good-quality trials31, 45, 53-55, 57, 59, 82, 96, 99, 116, 118, 125. Fair-quality trials often did not report randomization procedures, allocation concealment, or blinding of outcomes assessment. Many fair-quality trials also limited analyses to persons who completed the study. Some trials did not have allocation concealment of randomization or blinded outcome assessment. Some fair-quality trials, as opposed to good-quality trials, had higher attrition (for example, >20%), differential attrition, or differences in baseline characteristics between groups. Most trials, including the good-quality ones, did not report fidelity of or adherence to counseling interventions.

Trials included a representative range of persons. Men accounted for approximately 17% of all trial participants, or about 35% of trial participants excluding the largest trial that enrolled only women99. Eleven trials included only women48, 54, 61, 69, 70, 78, 92, 115, 118, 121, and 5 trials included only men42, 59, 64, 65, 103. Trials were primarily conducted in middle-aged adults (weighted mean age, 59 years [range, 20 to 78 years]). Nine trials37, 39, 45, 53, 59, 64, 66, 75, 87 were explicitly conducted in older adults, and most of these trials involved only physical activity counseling37, 39, 45, 53, 59, 64, 66. Among the 38 trials conducted in the United States, approximately 18% of participants were nonwhite (range in individual trials, 3% to 100%).

Counseling interventions ranged from low-intensity (such as those conducted in a single session or by mail alone) to very high-intensity (such as those with up to 20 sessions over 2 years). Trials were not evenly distributed across categories of study population risk (Table 1). Among diet counseling trials, low-intensity interventions were almost all conducted in general-risk persons and medium- to high-intensity interventions were mostly conducted in selected persons. In contrast, almost all of the physical activity counseling trials were conducted in persons who did not meet recommended levels of physical activity, and only 1 counseling intervention was high-intensity. The combined lifestyle counseling interventions showed a very different distribution, in that medium-intensity trials tended to target patients selected for risk factors related to cardiovascular disease, whereas high-intensity trials primarily involved unselected populations.

Key Question 1: Health Outcomes

Data on the morbidity or mortality related to cardiovascular disease were limited to 3 large, good-quality trials (Table 2). In the Women's Health Initiative Dietary Modification Trial (48,835 participants), postmenopausal women who were randomly assigned to intensive low-fat dietary counseling had no difference in major coronary heart disease events (hazard ratio [HR], 0.97 [95% CI, 0.90 to 1.06]), stroke (HR, 1.02 [CI, 0.90 to 1.15]), or death (HR, 0.98 [CI, 0.91 to 1.07]) after approximately 8.1 years of follow-up100, 101. Long-term observational follow-up of TOHP (Trials of Hypertension Prevention) I and II (3126 participants) showed that persons with mildly elevated diastolic blood pressure (80 to 89 mm Hg) who were randomly assigned to intensive sodium restriction counseling had fewer cardiovascular events and revascularization (2415 participants; HR, 0.70 [CI, 0.53 to 0.94]), but no difference in total mortality (3126 participants; HR, 0.80 [CI, 0.51 to 1.26]) after 10 to 15 years of follow-up134. A more conservative cardiovascular disease composite outcome (without revascularization) was not statistically significant, although the point estimate was similar (2415 participants; HR, 0.72 [CI, 0.50 to 1.03]). Visual inspection of cumulative incidence curves of cardiovascular disease events in TOHP I and II suggests that the intervention and control groups began to diverge at approximately 8 to 9 years of follow-up.

Key Question 2: Intermediate Outcomes

Medium- to high-intensity dietary interventions (with or without concomitant physical activity counseling) decreased body mass index at about 12 months. Statistical heterogeneity was high (I2 > 70%), making interpretation of pooled effect sizes questionable (Table 3). Two thirds of the trials of high-intensity dietary interventions, however, reported statistically significant group differences, suggesting that although the amount of weight change varied greatly from study to study, these interventions are likely to reduce weight (decrease in body mass index of approximately 0.3 to 0.7 kg/m2). Physical activity counseling trials were limited to primarily medium-intensity interventions for this outcome and generally did not reduce adiposity. Five trials evaluating high-intensity counseling had follow-up longer than 12 months; the reduction in body mass index persisted up to 72 months, although this result was slightly attenuated99, 113, 117, 118, 121.

High-intensity diet and lifestyle interventions decreased systolic and diastolic blood pressure by 1.5 mm Hg (CI, 0.9 to 2.1 mm Hg)78, 82, 91, 93, 96, 99, 104, 118, 121 and 0.7 mm Hg (CI, 0.6 to 0.9 mm Hg)78, 82, 91, 93, 96, 99, 104, 117, 118, 121, respectively, at 12 months (Table 3). The largest reduction in blood pressures occurred in 3 intensive salt-restriction counseling interventions in persons with mildly elevated diastolic blood pressure, resulting in a change of approximately -1.9 mm Hg (CI, -1.2 to -2.5 mm Hg) in systolic blood pressure and -1.0 mm Hg (CI, -0.5 to -1.6 mm Hg) in diastolic blood pressure at 12 months (Table 3)82, 93, 96. Reductions in blood pressure were still statistically significant, although slightly attenuated, at up to 36 months82, 93, 96. Four other trials reported follow-up beyond 12 months, but none showed a statistically significant reduction by the end of the trials99, 113, 118, 121. Meta-analyses of 6 trials showed that medium-intensity physical activity interventions did not improve blood pressure.

High-intensity trials targeting diet and combined lifestyle counseling decreased total and low-density lipoprotein cholesterol levels; changes were -0.17 mmol/L (CI, -0.09 to -0.25) (-6.56 mg/dL [CI, -3.47 to -9.65 mg/dL]) and -0.13 mmol/L (CI, -0.06 to -0.21) (-5.02 mg/dL [CI, -2.32 to -8.11 mg/dL]), respectively (Table 3)72, 91, 104, 117, 118, 121. Of the 3 trials that reported follow-up beyond 12 months, 2 trials conducted exclusively in women demonstrated a persistent decrease in total cholesterol or low-density lipoprotein cholesterol levels at 18 or 54 months118. There was no statistically significant increase in high-density lipoprotein cholesterol levels. Medium-intensity trials did not improve lipid levels on average. Very few trials that targeted physical activity alone reported lipid levels.

We found no evidence of statistically significant publication bias for any of the intermediate outcomes, on the basis of the Egger test and visual inspection of funnel plots. Trials that focused on physical activity–only counseling did not often report measures of adiposity, blood pressure, or lipids (8 studies; 3731 participants).

Key Question 3: Behavioral Outcomes

In general, counseling resulted in small increases in participants' physical activity levels, especially in trials that provided at least medium-intensity interventions. Twenty-four27-29, 31, 33, 35-37, 42, 47, 48, 50, 51, 53-55, 57, 59, 61, 63, 64, 69, 70, 133 of the 30 trials of physical activity interventions (12,938 participants) and 1342, 104, 106, 108, 111, 113-116, 118, 121, 124, 125 of the 17 combined lifestyle trials (4150 participants) were included in the meta-analyses of physical activity level. Pooled standardized mean differences for medium- and high-intensity interventions at approximately 12 months were 0.18 (CI, 0.12 to 0.24) and 0.26 (CI, 0.14 to 0.37), respectively (Table 4). These pooled estimates represent small changes in physical activity levels: for example, an increase in physical activity level by 38.3 min/wk (CI, 25.9 to 50.7 min/wk) (Table 4). Longer-term follow-up was very rare, but changes in activity level were maintained in 1 trial of medium-intensity physical activity71 and 1 trial of high-intensity physical activity plus lifestyle counseling that reported follow-up beyond 12 months118. The data for low-intensity interventions were mixed. Although the meta-analysis of the trials of low-intensity physical activity showed no overall effect, 4 of the 11 trials of low-intensity interventions increased some measure of physical activity35, 39, 55, 65; 2 of these 4 trials were not included in the meta-analysis because of limitations in reporting of outcomes at the individual study level. Only 1 of the combined lifestyle trials with this outcome involved a low-intensity intervention, and it showed no effect114. The Egger test of small study effects was statistically significant for the medium-intensity trials; however, sensitivity analyses without the smallest trials showed similar results.

Meta-analyses showed statistically significant reductions in self-reported total fat intake at all levels of intervention intensity; however, statistical heterogeneity was high (I2 > 70%) (Table 4). For high-intensity trials, 7 of 10 trials showed statistically significant reductions in total fat, suggesting a robust finding of group differences. High-intensity counseling resulted in moderate to large reductions in self-reported fat intake, ranging from a 5.9% to 11% decrease in energy from total fat and a 2.8% to 3.7% decrease in energy from saturated fat72, 78, 91, 99, 104, 117, 118. Four trials had longer-term follow-up (up to 72 months), during which reductions in total fat and saturated fat were still significant99, 117, 118, 121. Low- and medium-intensity interventions resulted in smaller reductions in fat intake42, 48, 74-77, 81, 86, 89, 92, 111, 114, 116, 124 None of the low- or medium-intensity counseling trials had follow-up beyond 12 months.

Healthful dietary counseling increased fruit and vegetable consumption at all levels of intervention intensity, although statistical heterogeneity was high in some subgroups (Table 4). Three fair-quality trials of behavioral counseling interventions focusing on fruit and vegetable consumption were successful in increasing fruit and vegetable intake37, 85, 87. Meta-analyses of the low- and medium-intensity general low-fat/heart-healthy counseling trials had low to modest heterogeneity and were statistically significant48, 75, 77, 86, 88, 90, 92. Although statistical heterogeneity was very large in the high-intensity trials, intervention group participants showed greater increases in fruit and vegetable consumption in 4 of the 5 trials77, 78, 99, 104, 121. Overall, the mean change in fruit and vegetable intake ranged from 0.4 to 2 servings per day. Only 2 trials had follow-up beyond 12 months; these showed a persistent increase in fruit and vegetable intake at 24 and 72 months37, 99.

Key Question 4: Harms

Adverse effects were rarely noted in physical activity counseling trials. Two trials reported minor muscular symptoms27, 50, and 3 trials reported falls related to physical activity31.53.54. We also found 7 case-crossover analyses, which showed that the risk for a cardiac event is increased 2-fold to 17-fold during vigorous exercise126-132. This increased risk was much greater for people with low baseline levels of regular activity. Nevertheless, the absolute risk for a cardiac event during physical activity was very low. One of these studies estimated that the incidence of sudden death associated with vigorous physical activity was 1 per 1.42 million person-hours of exercise126.

We found no studies designed to assess the adverse effects of dietary counseling or the adverse effects of increasing intake of fruits and vegetables or fiber and decreasing intake of sodium or fat. None of the healthful diet counseling trials reported specific adverse events.

 

Archived: Discussion

Medium- to high-intensity dietary behavioral counseling, with or without physical activity counseling, resulted in small but statistically significant improvements in adiposity, blood pressure, and cholesterol level, as well as moderate to large changes in self-reported dietary and physical activity behaviors. The evidence for changes in physiologic outcomes was strongest for high-intensity counseling interventions. The reductions in blood pressure, about 1.5 mm Hg (systolic) and 0.7 mm Hg (diastolic), were smaller than those seen in hypertension drug trials and feeding trials134, 135. However, epidemiologic data suggest that even changes as small as 2 mm Hg in systolic blood pressure can decrease the risk for coronary heart disease by 6% or stroke by 16%136. Direct evidence from observational follow-up of the large hypertension prevention trials that used sodium reduction counseling suggest that these small changes in blood pressure can result in a 30% reduction in cardiovascular disease events and revascularization in persons with mildly elevated diastolic blood pressure137. Reductions in cholesterol level were also small (about 0.17 mmol/L [5.02 mg/dL] in total cholesterol level). On the basis of randomized, controlled trials in primary prevention, a sustained reduction of 0.6 mmol/L (23.17 mg/dL) in total serum cholesterol level—an average decrease of 10%—can reduce coronary heart disease by about 25%138. However it is unclear whether smaller reductions in total cholesterol level due to dietary changes can affect cardiovascular disease.

Medium- to high-intensity physical activity counseling also resulted in small changes in self-reported physical activity (an increase of about 40 minutes per week). Evidence suggests that even low-intensity dietary counseling results in moderate increases in fruit and vegetable intake (up to 2 servings a day) and small decreases in dietary fat intake (about 1.5% decrease in energy intake from total fat). Evidence for low-intensity physical counseling interventions for increasing self-reported physical activity was mixed.

Evidence for maintenance of any behavioral or physiologic effects beyond 12 months was very limited. The interventions with significant benefit beyond 12 months were all high-intensity counseling interventions with group, phone, or mail contact throughout the trial. Most trials for high-intensity interventions that had follow-up beyond 12 months showed persistent beneficial changes in adiposity and lipid levels (but not blood pressure), as well as improvements in self-reported behavioral outcomes.

Intervention intensity was the most important factor for differences in effect size among different trials. However, the effects of counseling intensity could not be fully disentangled from the risk among the populations studied. Although trials in populations with known traditional cardiovascular risk factors or risk equivalents were excluded, many of the medium- to high- intensity interventions were conducted in participants selected for suboptimal lifestyle behaviors or factors associated with increased cardiovascular disease (Table 2). In multivariate meta-regression, both intervention intensity and risk in the population predicted larger effects. In addition, some participant populations were volunteers. Exploratory meta-regressions suggested that use of volunteer participants was also predictive of larger effect sizes, although in multivariate analyses this was significant only for dietary fat intake. Almost all of the effective medium- to high-intensity interventions were delivered by specially trained health educators or nurses, counselors or psychologists, dietitians or nutritionists, or exercise instructors or physiologists; very few involved the primary care provider (Table 2). Many of the high-intensity interventions used 12 or more sessions and therefore required resources that may not be available or paid for in the current health care system (in addition to raising issues of real-world patient adherence).

No increase in serious injuries occurred from physical activity or unintended adverse changes in dietary intake, on the basis of available counseling trials (Table 3). Two trials reported a paradoxical increase in carbohydrate intake but not overall caloric intake. The clinical significance of these dietary changes is unclear. In the Women's Health Initiative, the replacement of fat intake with complex carbohydrates over 6 years was not associated with adverse effects on lipid profiles139. Observational studies suggest an increased risk for serious cardiac events during vigorous physical activity, primarily in persons with low levels of habitual activity. However, the absolute risk for serious cardiac events related to physical activity seems very small. The U.S. Department of Health and Human Services' 2008 report on physical activity16 details additional information regarding harms of physical activity.

In addition to limited confidence in the pooled estimates of effect sizes for some outcomes due to the heterogeneity of the trials, this body of evidence has other limitations. Our updated review represents only a subset of the diet and physical activity counseling literature; important omissions include counseling in persons with known disease (including hypertension, dyslipidemia, diabetes, or coronary heart disease); diet or physical activity counseling for other types of disease prevention or weight management; trials to evaluate the comparative effectiveness of different types of counseling interventions; related behavioral interventions conducted through worksites, schools, and communities; and public health, economic- and policy-oriented, or media-based interventions140.

Most of the trials relied on self-reported behavioral outcome measures; only 36% of trials reported any objectively measured intermediate outcomes. Measurement of behavioral outcomes varied across trials, and both dietary and physical activity behaviors can be difficult to measure validly and reliably (Table 4). Dietary intake was generally measured by food-frequency questionnaires, food diaries, and 24-hour food recalls, each of which can be prone to bias141. For physical activity, the various forms of physical activity, the episodic nature of some types of activity, and the subjective nature of a person's assessment of intensity make it difficult to get precise information on physical activity levels. Only 7 of the studies that reported physical activity outcomes used objective measures, such as a pedometer, accelerometer, or actigraph45, 48, 50, 64, 67, 106, 115, 118, and this measure was always used in addition to a self-reported measure. However, the behavioral outcome results in our review were generally consistent with those that used intermediate outcomes.

Other limitations include risk for bias due to inclusion only of published data, potential selective reporting of outcomes, and inclusion of trials that used volunteer participants. The Egger statistical test for small-study effects was significant only for self-reported total dietary fat intake and self-reported physical activity level among the physical activity counseling trials. However, sensitivity analyses that excluded the small studies with large effects still demonstrated a positive effect of physical activity counseling.

Although the body of literature is already very large, good-quality trials that fully evaluate the longer-term health effects of these types of counseling interventions across a range of patients and use counseling interventions that are most applicable to primary care are needed. More trials are needed to evaluate low-intensity counseling interventions that could be more readily implemented in primary care, or medium-intensity interventions that could be referred to from primary care. The effective high-intensity interventions should be studied for reproducibility, to determine whether they would work in other populations and what intensity of intervention is effective in lower-risk populations. More trials with longer-term follow-up are crucial to understanding how to maintain behavioral change and changes in physiologic outcomes over time. In addition to self-reported behavioral outcomes, trials should also collect and report objectively measured physiologic outcomes. Greater use of objective measures to assess physical activity would probably provide more accurate estimates of changes in physical activity level, which is especially important when the changes are small.

 

Archived: Copyright and Source Information

Source: Agency for Healthcare Research and Quality, Rockville, Maryland.

Acknowledgment: The authors thank Daphne Plaut, MLS, for conducting the literature searches; Kevin Lutz, MFA, for editorial support; Sarah Zuber, MSW, and Leslie Perdue, MPH, for assistance in conducting the evidence review; and Caitlyn Senger, MPH, for assistance in preparing the manuscript. They also thank the Agency for Healthcare Research and Quality and the USPSTF, as well as the expert reviewers (Miriam C. Morey, PhD; Michele M. Doucette, PhD; Charlotte A. Pratt, PhD, RD; Janet M. de Jesus, MS, RD; Brian Martinson, PhD; Stephen P. Fortmann, MD; David R. Brown, PhD; and David P. Hopkins, MD, MPH), for their contribution to this evidence review.

Potential Conflicts of Interest: Disclosures can be viewed at www.acponline.org/authors/icmje/ConflictOfInterestForms.do?msNum=M10-1648.

Requests for Single Reprints: Copies of the full report on which this article is based are available at www.uspreventiveservicestaskforce.org/.

Current author addresses and author contributions are available at http://www.annals.org.

AHRQ Publication No. 11-05149-EF-3 

 

Archived: Appendix Figure. Analytic framework and key questions

Select Text Description below for details

[D] Select for Text Description.

The Appendix Figure is an analytic framework that depicts the events that individuals experience while undergoing counseling for a healthy lifestyle for the purposes of improving cardiovascular health outcomes. The framework includes 6 headers: Patient Population, Counseling Intervention, Intermediate Outcomes, Behavioral Outcomes, Health Outcomes, and Adverse Effects. The patient population is adults and older adults both with and without cardiovascular risk factors. The intervention is behavioral counseling for a healthful diet and/or physical activity. The intermediate outcomes, which are used to determine if the counseling is effective, include blood pressure, cholesterol, glucose tolerance, weight, and body mass index. The behavioral outcomes include physical activity and dietary intake. The health outcomes include decreased cardiovascular risk and related morbidity and mortality. Adverse effects of counseling for physical activity include mild muscle fatigue or soreness, injuries, and falls. Adverse effects of counseling for a healthful diet include unintended changes in other food or nutrient intake.

Key Questions
1. Do primary care-relevant behavioral counseling interventions for physical activity or healthful diet improve cardiovascular disease health outcomes (prevent morbidity and mortality) in adults?
2. Do primary care-relevant behavioral counseling interventions for physical activity or healthful diet improve intermediate outcomes associated with cardiovascular disease (such as lipid levels, blood pressure, glucose tolerance, weight, or body mass index) in adults (including older adults)?
3. Do primary care-relevant behavioral counseling interventions for physical activity or healthful diet change associated health behaviors in adults?
4. What are the adverse effects of primary care-relevant behavioral counseling interventions for physical activity or healthful diet in adults?

Archived: Figure. Summary of evidence search and selection

The figure is a flow chart that summarizes the search and selection of articles. There were 15,490 citations identified by searching MEDLINE, PsycInfo, and Cochrane databases. There were an additional 643 citations identified through other means (for example, suggestions from experts and reference lists from other publications). After removal of duplicates, 13,562 citations remained. Of these, 13,088 citations were excluded after abstract review. Reasons for exclusion included not relevant data (n=18), wrong setting (n=6), wrong population (n=100), no outcomes of interest (n=35), no interventions of interest (n=98), wrong study design (n=104), and poor study quality (n=46). (Note that 28 articles were excluded for different reasons in different areas and 7 were excluded for one area and included for another). The remaining 481 full-text articles were assessed for eligibility, and 109 of these articles were deemed eligible for inclusion. Of these 109 articles, 40 were included in the qualitative synthesis for healthful diet, 37 were included in the qualitative synthesis for physical activity, and 17 were included in the qualitative synthesis for combined lifestyle (8 articles were included in more than one area).

KQ = key question.
* We excluded 28 articles for different reasons in different areas; 7 were excluded for 1 area and included for another.
†We included 8 studies in more than 1 area.
‡Additional studies identified for harms (not including trials included for KQs 1 to 3).

Archived: Table 1. Counseling Trials, by Intervention Intensity and Population Risk

Intervention Intensity and PCP Role Unselected Population Population Selected for Suboptimal Diet or Exercise Behavior Population Selected for Increased Cardiovascular Risk
Low-intensity intervention (estimated 0–30 min)
Substantial PCP role in intervention Beresford et al, 199774*
Sacerdote et al, 200690*
Katz et al, 200847
Aittasalo et al, 200627
Goldstein et al, 199933
Grandes et al, 200935
 
No PCP role in intervention
Conducted in or recruited from primary care or health plan Carpenter et al, 200477*
Fries et al, 200581*
John et al, 200285*
Kristal et al, 200086*
Lutz et al, 199987*
Roderick et al, 199789*
Prochaska et al, 200588*
Halbert et al, 200039
 
Not conducted in or recruited from primary care or health plan De Vet et al, 200928
Stensel et al, 199465
Jeffery and French, 1999114
Marcus et al, 200755
Marshall et al, 200356
Napolitano et al, 200661
Pekmezi et al, 200970
 
Medium-intensity intervention (estimated 31–360 min)
PCP role in intervention Baron et al, 199073*
Green et al, 200236
Norris et al, 200063
Elley et al, 200331
Lawton et al, 200854
Pinto et al, 200564
Kallings et al, 200945
No PCP role in intervention
Conducted in or recruited from primary care or health plan Morey et al, 200959 Delichatsios et al, 200129*
Harland et al, 199941
Kinmonth et al, 200851
Kolt et al, 200753
Hellénius et al, 199342*
Stevens et al, 200392*
Yates et al, 2009133
Babazono et al, 2007106
Eakin et al, 2007108
Hardcastle et al, 2008111
Keyserling et al, 2008115
Mosca et al, 2008116
Wister et al, 2007125
Not conducted in or recruited from primary care or health plan Connell and Janevic, 200969
Martinson et al, 200857
Franko et al, 2008110
Vandelanotte et al, 2005124
Greene et al, 200837*
Bernstein et al, 200275*
King et al, 200248*
King et al, 200750
Marcus et al, 200755
Brekke et al, 200576*
Watanabe et al, 2003103*
High-intensity intervention (estimated >360 min)
No PCP role in intervention
Conducted in or recruited from primary care or health plan   Stewart et al, 200166 Edelman et al, 2006109
Oldroyd et al, 2001117
Not conducted in or recruited from primary care or health plan Carpenter et al, 200477*
Aldana et al, 2006104
Hivert et al, 2007113
Simkin-Silverman et al, 1995119
Thompson et al, 2008121
Coates et al, 199978*
Tinker et al, 200899*
Shah et al, 199083*
TOHP, phase I, 199293*
TOHP, phase II, 199796*
Stefanick et al, 199891*
Anderson et al, 199272*

PCP = primary care provider; TOHP = Trials of Hypertension Prevention.
* Healthful diet counseling.
† Physical activity counseling.
‡ Combined healthful diet and physical activity counseling.

Archived: Table 2. Summary of Evidence

Key Question Studies and
Participants
Design Overall Quality Consistency Applicability Summary of Findings
1. Do primary care-relevant behavioral counseling interventions for physical activity or healthful diet reduce CVD in adults?
  3 studies, 51,961 participants RCT Fair; only 3 HD trials, all of good quality; 2 trials with observational follow-up after trials were completed Fair; trials evaluated different interventions in different populations Fair; largest trial in postmenopausal women; 2 trials in prehypertension In WHI, high-intensity general low-fat counseling did not significantly decrease major CVD events at 8.1 y. Observational follow-up of TOHP I and II showed that high-intensity sodium reduction counseling in prehypertensive patients decreased CVD events and revascularization at 10 to 15 y.
2. Do primary care-relevant behavioral counseling interventions for physical activity or healthful diet improve intermediate outcomes (e.g., adiposity, blood pressure, lipids) in adults?
Evidence for physical activity counseling alone PA only: 8 studies, 3731 participants RCT Fair; intermediate outcomes not commonly reported; limited evidence beyond 12 mo Good Fair; only 1 trial conducted in the United States Sparsely reported findings. Pooled estimates showed that mostly medium-intensity counseling did not improve adiposity, blood pressure, or lipid levels. Two trials showed statistically significant group differences in adiposity, blood pressure, or lipid levels; however, the remaining trials did not.
Evidence for healthful diet counseling, with or without physical activity counseling HD only: 16 studies, 58,557 participants CL: 14 studies, 3855 participants RCT Fair; very high I2 value for adiposity meta-analyses; limited evidence beyond 12 mo Fair; HD and CL trials were not distributed consistently by intervention intensity and population risk Good High-intensity counseling for healthful diet resulted in statistically significant reductions in adiposity, blood pressure, and total and LDL cholesterol. Body mass index was reduced by approximately 0.3 to 0.7 kg/m2. Systolic and diastolic blood pressure were reduced by 1.5 and 0.7 mm Hg. Total and LDL cholesterol were reduced by 0.17 and 0.13 mmol/L (6.56 and 5.02 mg/dL). No statistically significant changes were seen for HDL cholesterol or triglycerides.
3. Do primary care-relevant behavioral counseling interventions for physical activity or healthful diet change associated health behaviors in adults?
Evidence for change in physical activity PA only: 30 studies, 15,265 participants CL: 15 studies, 4975 participants RCT Fair; wide variety in measurement of physical activity; mostly self-reported measures; positive Egger result; limited evidence beyond 12 mo Fair; PA and CL trials were not distributed consistently by intervention intensity and population risk Good; most trials conducted in persons selected for sedentary behavior or some increased risk for CVD Medium- to high-intensity interventions improved self-reported measures of physical activity by approximately 38 min/wk. This modest increase meant that most persons exercised for at least 1 h/wk. Results for the effectiveness of low-intensity counseling were mixed. Although the pooled estimate was not statistically significant, 4 trials (2 of which were not in the meta-analysis) showed statistically significant improvements in self-reported activity levels.
Evidence for change in dietary intake HD only: 25 studies, 71,267 participants CL: 16 studies, 4951 participants RCT Fair; high I2 value for all dietary intake meta-analyses; mostly self-reported measures; positive Egger result for total fat dietary intake; limited evidence beyond 12 mo Fair; HD and CL trials were not distributed consistently by intervention intensity and population risk Good High-intensity counseling resulted in moderate to large reductions in self-reported fat intake, a 5.9% to 11% decrease in energy from total fat, and a 2.8% to 3.7% decrease in energy from saturated fat. Low- to medium-intensity interventions resulted in smaller changes. Low- to high-intensity counseling yielded moderate to large increases in fruit and vegetable intake ranging from about 0.4 to 2 servings/d.
4. What are the adverse effects of primary care-relevant behavioral counseling interventions for physical activity or healthful diet in adults?
Evidence for harms of physical activity or counseling to improve physical activity Trials: 2 studies, 483 participants Observational studies: 7 studies, 4354 cases RCT (case-crossover) Fair; adverse events rarely reported in trials; case-crossover design; difficult to measure habitual PA; only 1 study reported absolute risk for cardiac event during vigorous physical activity Good Fair; observational studies often limited to nonfatal cases; most case patients were men In 2 trials, almost 25% of participants reported mild muscular fatigue, strain, or soreness. In observational studies, risk for serious cardiac events was increased during vigorous physical activity. This increased risk was much greater in people with low levels of habitual physical activity. However, the absolute risk for a cardiac event is very small.
Evidence for harms of healthful diet or counseling to improve diet HD only: 25 studies, 71,267 participants CL: 16 studies, 4951 participants RCT Fair; explicit adverse events not reported in trials Good Good No specific examination of adverse effects; however, 2 trials showed an increased intake of carbohydrates with no increase in overall energy intake. Overall, few trials reported dietary intake of monounsaturated or polyunsaturated fats, carbohydrates, or sugars.

CL = combined lifestyle counseling; CVD = cardiovascular disease; HD = healthful diet counseling; HDL = high-density lipoprotein; LDL = low-density lipoprotein; PA = physical activity counseling; RCT = randomized, controlled trial; TOHP = Trials of Hypertension Prevention; WHI = Women's Health Initiative.

Archived: Table 3. Pooled Effect Sizes for Intermediate Outcomes

Intervention Target Low-Intensity Interventions Medium-Intensity Interventions High-Intensity Interventions
  Effect Size (95% CI) Trials, n I2, % Effect Size (95% CI) Trials, n I2, % Effect Size (95% CI) Trials, n I2, %
Adiposity (standardized effect size)
All -0.10 (-0.22 to 0.02) 5* 69.6 -0.14 (-0.27 to -0.01) 12 71.2 -0.48 (-0.64 to -0.32) 9 89.8
Physical activity -0.15 (-0.66 to 0.36) 1 - -0.09 (-0.24 to 0.06) 7 72.2 - 0 -
Healthful diet (general) -0.16 (-0.33 to 0.00) 2 77.0 -0.57 (-0.93 to -0.21) 2 0.0 -0.37 (-0.52 to -0.22) 4 85.4
Combined lifestyle -0.04 (-0.17 to 0.10) 1 - -0.34 (-0.61 to -0.07) 6 78.1 -0.54 (-0.82 to -0.25) 5 80.9
Systolic blood pressure, mm Hg
All -1.2 (-3.3 to 1.0) 3* 79.5 -0.5 (-1.8 to 0.8) 13 46.5 -1.5 (-2.1 to -0.9) 10 49.0
Physical activity - 0 - -0.57 (-1.9 to 0.7) 6 14.0 - 0 -
Healthful diet (low-salt) - 0 - - 0 - -1.9 (-2.5 to -1.2) 3 0.0
Healthful diet (general) 0.1 (-0.8 to 1.0) 2 0.0 -6.0 (-11.0 to -1.0) 1 - -1.0 (-1.6 to -0.3) 3 26.0
Combined lifestyle - 0 - -0.8 (-3.0 to 1.5) 6 59.4 -1.9 (-3.2 to -0.5) 4 2.7
Diastolic blood pressure, mm Hg
All -0.5 (-1.2 to 0.2) 3 7.3 -0.3 (-1.4 to 0.8) 9 63.2 -0.7 (-0.9 to -0.6) 10 0.0
Physical activity - 0 - -0.5 (-1.9 to 0.8) 5 58.5 - 0 -
Healthful diet (low-salt) - 0 - - 0 - -1.0 (-1.6 to -0.5) 3 0.0
Healthful diet (general) -0.2 (-0.9 to 0.6) 2 0.0 -5.0 (-7.8 to -2.2) 1 - -0.7 (-0.8 to -0.6) 3 0.0
Combined lifestyle - 0 - -0.3 (-2.3 to 1.7) 5 71.9 -1.1 (-2.4 to 0.2) 4 36.5
Total cholesterol level, mmol/L§
All 0.02 (-0.09 to 0.13) 1 - -0.04 (-0.11 to 0.02) 14 44.6 -0.17 (-0.25 to -0.09) 6 30.9
Physical activity - 0 - -0.05 (-0.13 to 0.04) 6 23.9 - 0 -
Healthful diet (general) - 0 - -0.05 (-0.11 to 0.01) 4 0.0 -0.23 (-0.35 to -0.11) 2 0.0
Combined lifestyle - 0 - -0.05 (-0.20 to 0.10) 7 64.5 -0.13 (-0.25 to 0.00) 4 50.0
Low-density lipoprotein cholesterol level, mmol/L§
All - 0 - -0.01 (-0.10 to 0.08) 9 34.4 -0.13 (-0.21 to -0.06) 6 32.1
Physical activity - 0 - -0.02 (-0.18 to 0.14) 3 31.2 - 0 -
Healthful diet (general) - 0 - -0.08 (-0.23 to 0.07) 3 20.3 -0.19 (-0.31 to -0.08) 2 11.7
Combined lifestyle - 0 - 0.00 (-0.13 to 0.12) 6 46.5 -0.10 (-0.20 to 0.00) 4 38.1

* Includes an additional trial of healthful diet counseling that targeted fruit and vegetable intake (not shown separately).
† P ≤ 0.05.
‡ Total number of trials is fewer than the sum of the subgroups because some trials had multiple groups with different intervention targets and are therefore included in multiple subgroups.
§ To convert mmol/L to mg/dL, divide by 0.0259.

Archived: Table 4. Pooled Effect Sizes of Behavioral Outcomes

Intervention Target Low-Intensity Interventions Medium-Intensity Interventions High-Intensity Interventions
  Effect Size (95% CI) Trials, n I2, % Effect Size (95% CI) Trials, n I2, % Effect Size (95% CI) Trials, n I2, %
Self-reported physical activity, standardized
All 0.07 (0.0 to 0.15)* 9 32.2 0.18 (0.12 to 0.24)* 24 41.9 0.26 (0.14 to 0.37)* 4 0.0
Physical activity 0.08 (-0.01 to 0.18) 8 40.7 0.19 (0.12 to 0.27)* 17 49.9 - 0 -
Combined lifestyle 0.06 (-0.08 to 0.19) 1 - 0.20 (0.08 to 0.33)* 8 45.7 0.26 (0.14 to 0.37)* 4 0.0
Self-reported physical activity in the subset reporting min/wk, min/wk
All 33.6 (1.7 to 65.6)* 6 38.6 40.9 (19.5 to 62.3)* 12 78.7 51.5 (-62.6 to 165.8) 1 -
Physical activity 33.6 (1.7 to 65.6)* 6 38.6 38.3 (25.9 to 50.7)* 9 0.0 - 0 -
Combined lifestyle - 0 - 50.4 (-23.9 to 124.6) 3 82.4 51.5 (-62.6 to 165.8) 1 -
Self-reported fat intake, standardized
All -0.23 (-0.29 to -0.18)* 6 0.0 -0.28 (-0.61 to 0.04)* 8 91.5 -0.81 (-1.13 to -0.50)* 10 97.5
Healthful diet (general) -0.25 (-0.31 to -0.19)* 5 0.0 -0.46 (-0.81 to -0.11)* 5 73.3 -1.05 (-1.36 to -0.74)* 5 96.3
Combined lifestyle -0.15 (-0.29 to -0.01)* 1 - -0.24 (-0.65 to 0.16) 5 91.7 -0.61 (-1.11 to -0.11)* 5 93.6
Self-reported fruit and vegetable intake, standardized
All 0.34 (0.17 to 0.52)* 6 92.2 0.36 (0.10 to 0.62)* 6 88.0 0.57 (0.33 to 0.81)* 5 94.9
Healthful diet (fruit and vegetable intake) 0.60 (0.08 to 1.11)* 2 93.8 0.36 (0.22 to 0.50)* 1 - - 0 -
Healthful diet (general) 0.19 (0.14 to 0.23)* 4 0.0 0.65 (0.38 to 0.92)* 3 44.0 0.68 (0.37 to 0.99)* 3 96.8
Combined lifestyle - 0 - 0.00 (-0.14 to 0.14) 2 0.0 0.40 (-0.16 to 0.96) 2 90.0

* P ≤ 0.05.
† Total number of trials is fewer than the sum of the subgroups because some trials had multiple groups with different intervention targets and therefore are included in multiple subgroups.

References:
  1. Mokdad AH, Marks JS, Stroup DF, Gerberding JL. Actual causes of death in the United States, 2000. JAMA. 2004;291:1238-45. [PMID: 15010446]
  2. McGinnis JM, Foege WH. Actual causes of death in the United States. JAMA. 1993;270:2207-12. [PMID: 8411605]
  3. Institute of Medicine. DRI Dietary Reference Intakes: The Essential Guide to Nutrient Requirements. Washington, DC: National Academies Pr; 2006.
  4. Joint WHO-FAO Expert Consultation. Diet, Nutrition and the Prevention of Chronic Diseases. WHO Technical Report Series (916). Geneva: World Health Organization; 2003.
  5. Physical Activity Guidelines Advisory Committee. Physical Activity Guidelines Advisory Committee Report, 2008. Washington, DC: U.S. Department of Health and Human Services; 2008.
  6. U.S. Department of Health and Human Services. 2008 Physical Activity Guidelines for Americans. ODPHP Publication No. U0036. Washington, DC: U.S. Department of Health and Human Services; 2008.
  7. Centers for Disease Control and Prevention and President's Council on Physical Fitness and Sports. Midcourse Review: Healthy People 2010—Physical Activity and Fitness. Washington, DC: U.S. Department of Health and Human Services; 2006:22-3-22-26.
  8. U.S. Department of Health and Human Services and U.S. Department of Agriculture. Dietary Guidelines for Americans, 2005. 6th ed. Washington, DC, U.S. Government Printing Office; 2005.
  9. Wells HF. Dietary Assessment of Major Trends in U.S. Food Consumption, 1970-2005. Economic Information Bulletin no. 33. Washington, DC: U.S. Department of Agriculture Economic Research Service; 2008.
  10. Lin JS, O'Connor E, Whitlock EP, Beil TL, Zuber SP, Perdue LA, et al. Behavioral Counseling to Promote Physical Activity and a Healthful Diet to Prevent Cardiovascular Disease in Adults: Update of the Evidence for the U.S. Preventive Services Task Force. Evidence Synthesis No. 79, AHRQ Publication No. 11-05149-EF-1. Rockville, MD: Agency for Healthcare Research and Quality; 2010.
  11. Eden KB, Orleans CT, Mulrow CD, Pender NJ, Teutsch SM. Clinician counseling to promote physical activity. Rockville, MD: Agency for Healthcare Research and Quality; 2002;34.
  12. Ammerman A, Pignone M, Fernandez L, Lohr K, Driscoll JA, Nester C, et al. Counseling to promote a Healthful Diet. Rockville, MD: Agency for Healthcare Research and Quality; 2003;145.
  13. Thompson RL, Summerbell CD, Hooper L, Higgins JP, Little PS, Talbot D, et al. Dietary advice given by a dietitian versus other health professional or self-help resources to reduce blood cholesterol. Cochrane Database Syst Rev. 2003:CD001366. [PMID: 12917906]
  14. Hooper L, Bartlett C, Davey SG, Ebrahim S. Advice to reduce dietary salt for prevention of cardiovascular disease. Cochrane Database Syst Rev. 2004: CD003656. [PMID: 14974027]
  15. Lemmens VE, Oenema A, Klepp KI, Henriksen HB, Brug J. A systematic review of the evidence regarding efficacy of obesity prevention interventions among adults. Obes Rev. 2008;9:446-55. [PMID: 18298429]
  16. Ammerman AS, Lindquist CH, Lohr KN, Hersey J. The efficacy of behavioral interventions to modify dietary fat and fruit and vegetable intake: a review of the evidence. Prev Med. 2002;35:25-41. [PMID: 12079438]
  17. Kahn EB, Ramsey LT, Brownson RC, Heath GW, Howze EH, Powell KE, et al. The effectiveness of interventions to increase physical activity. A systematic review. Am J Prev Med. 2002;22:73-107. [PMID: 11985936]
  18. Holtzman J, Schmitz K, Babes G, Kane RL, Duval S, Wilt TJ, et al. Effectiveness of Behavioral Interventions to Modify Physical Activity Behaviors in General Populations and Cancer Patients and Survivors. Rockville, MD: Agency for Healthcare Research and Quality; 2004;336.
  19. Hillsdon M, Foster C, Thorogood M. Interventions for promoting physical activity. Cochrane Database Syst Rev. 2005:CD003180. [PMID: 15674903]
  20. van der Bij AK, Laurant MG, Wensing M. Effectiveness of physical activity interventions for older adults: a review. Am J Prev Med. 2002;22:120-33. [PMID: 11818183]
  21. Eakin EG, Lawler SP, Vandelanotte C, Owen N. Telephone interventions for physical activity and dietary behavior change: a systematic review. Am J Prev Med. 2007;32:419-34. [PMID: 17478269]
  22. U.S. Preventive Services Task Force. U.S. Preventive Services Task Force Procedure Manual. (AHRQ Publication No. 08-05118-EF). Rockville, MD: Agency for Healthcare Research and Quality; 2008. Accessed at http://www.uspreventiveservicestaskforce.org/Page/Name/procedure-manual on 15 October 2010.
  23. Higgins JP, Thompson SG. Quantifying heterogeneity in a meta-analysis. Stat Med. 2002;21:1539-58. [PMID: 12111919]
  24. Egger M, Davey Smith G, Schneider M, Minder C. Bias in meta-analysis detected by a simple, graphical test. BMJ. 1997;315:629-34. [PMID: 9310563]
  25. Terrin N, Schmid CH, Lau J. In an empirical evaluation of the funnel plot, researchers could not visually identify publication bias. J Clin Epidemiol. 2005; 58:894-901. [PMID: 16085192]
  26. Cohen J. Statistical power for analysis for the behavioral sciences. Hillsdale, NJ: Lawrence Erlbaum Associates; 1988.
  27. Aittasalo M, Miilunpalo S, Kukkonen-Harjula K, Pasanen M. A randomized intervention of physical activity promotion and patient self-monitoring in primary health care. Prev Med. 2006;42:40-6. [PMID: 16297442]
  28. De Vet E, Oenema A, Sheeran P, Brug J. Should implementation intentions interventions be implemented in obesity prevention: the impact of if-then plans on daily physical activity in Dutch adults. Int J Behav Nutr Phys Act. 2009;6:11. [PMID: 19267889]
  29. Delichatsios HK, Friedman RH, Glanz K, Tennstedt S, Smigelski C, Pinto BM, et al. Randomized trial of a "talking computer" to improve adults' eating habits. Am J Health Promot. 2001;15:215-24. [PMID: 11349340]
  30. Pinto BM, Friedman R, Marcus BH, Kelley H, Tennstedt S, Gillman MW. Effects of a computer-based, telephone-counseling system on physical activity. Am J Prev Med. 2002;23:113-20. [PMID: 12121799]
  31. Elley CR, Kerse N, Arroll B, Robinson E. Effectiveness of counselling patients on physical activity in general practice: cluster randomised controlled trial. BMJ. 2003;326:793. [PMID: 12689976]
  32. Kerse N, Elley CR, Robinson E, Arroll B. Is physical activity counseling effective for older people? A cluster randomized, controlled trial in primary care. J Am Geriatr Soc. 2005;53:1951-6. [PMID: 16274377]
  33. Goldstein MG, Pinto BM, Marcus BH, Lynn H, Jette AM, Rakowski W, et al. Physician-based physical activity counseling for middle-aged and older adults: a randomized trial. Ann Behav Med. 1999;21:40-7. [PMID: 18425653]
  34. Pinto BM, Goldstein MG, DePue JD, Milan FB. Acceptability and feasibility of physician-based activity counseling. The PAL project. Am J Prev Med. 1998;15:95-102. [PMID: 9713664]
  35. Grandes G, Sanchez A, Sanchez-Pinilla RO, Torcal J, Montoya I, Lizarraga K, et al; PEPAF Group. Effectiveness of physical activity advice and prescription by physicians in routine primary care: a cluster randomized trial. Arch Intern Med. 2009;169:694-701. [PMID: 19364999]
  36. Green BB, McAfee T, Hindmarsh M, Madsen L, Caplow M, Buist D. Effectiveness of telephone support in increasing physical activity levels in primary care patients. Am J Prev Med. 2002;22:177-83. [PMID: 11897462]
  37. Greene GW, Fey-Yensan N, Padula C, Rossi SR, Rossi JS, Clark PG. Change in fruit and vegetable intake over 24 months in older adults: results of the SENIOR project intervention. Gerontologist. 2008;48:378-87. [PMID: 18591363]
  38. Greaney ML, Riebe D, Ewing Garber C, Rossi JS, Lees FD, Burbank PA, et al. Long-term effects of a stage-based intervention for changing exercise intentions and behavior in older adults. Gerontologist. 2008;48:358-67. [PMID: 18591361]
  39. Halbert JA, Silagy CA, Finucane PM, Withers RT, Hamdorf PA. Physical activity and cardiovascular risk factors: effect of advice from an exercise specialist in Australian general practice. Med J Aust. 2000;173:84-7. [PMID: 10937036]
  40. Halbert JA, Silagy CA, Finucane P, Withers RT, Hamdorf PA. Recruitment of older adults for a randomized, controlled trial of exercise advice in a general practice setting. J Am Geriatr Soc. 1999;47:477-81. [PMID: 10203125]
  41. Harland J, White M, Drinkwater C, Chinn D, Farr L, Howel D. The Newcastle exercise project: a randomised controlled trial of methods to promote physical activity in primary care. BMJ. 1999;319:828-32. [PMID: 10496829]
  42. Hellénius ML, de Faire U, Berglund B, Hamsten A, Krakau I. Diet and exercise are equally effective in reducing risk for cardiovascular disease. Results of a randomized controlled study in men with slightly to moderately raised cardiovascular risk factors. Atherosclerosis. 1993;103:81-91. [PMID: 8280188]
  43. Hellénius ML, Dahlöf C, Aberg H, Krakau I, de Faire U. Quality of life is not negatively affected by diet and exercise intervention in healthy men with cardiovascular risk factors. Qual Life Res. 1995;4:13-20. [PMID: 7711685]
  44. Näslund GK, Fredrikson M, Hellénius ML, de Faire U. Effect of diet and physical exercise intervention programmes on coronary heart disease risk in smoking and non-smoking men in Sweden. J Epidemiol Community Health. 1996; 50:131-6. [PMID: 8762375]
  45. Kallings LV, Sierra Johnson J, Fisher RM, Faire U, Ståhle A, Hemmingsson E, et al. Beneficial effects of individualized physical activity on prescription on body composition and cardiometabolic risk factors: results from a randomized controlled trial. Eur J Cardiovasc Prev Rehabil. 2009;16:80-4. [PMID: 19237997]
  46. Kallings LV. Physical activity on prescription: studies on physical activity level, adherence, and cardiovascular risk factors [dissertation]. Stockholm: Karolinska Institutet; 2008.
  47. Katz DL, Shuval K, Comerford BP, Faridi Z, Njike VY. Impact of an educational intervention on internal medicine residents' physical activity counselling: the Pressure System Model. J Eval Clin Pract. 2008;14:294-9. [PMID: 18324934]
  48. King AC, Baumann K, O'Sullivan P, Wilcox S, Castro C. Effects of moderate-intensity exercise on physiological, behavioral, and emotional responses to family caregiving: a randomized controlled trial. J Gerontol A Biol Sci Med Sci. 2002;57:M26-36. [PMID: 11773209]
  49. Castro CM, Wilcox S, O'Sullivan P, Baumann K, King AC. An exercise program for women who are caring for relatives with dementia. Psychosom Med. 2002;64:458-68. [PMID: 12021419]
  50. King AC, Friedman R, Marcus B, Castro C, Napolitano M, Ahn D, et al. Ongoing physical activity advice by humans versus computers: the Community Health Advice by Telephone (CHAT) trial. Health Psychol. 2007;26:718-27. [PMID: 18020844]
  51. Kinmonth AL, Wareham NJ, Hardeman W, Sutton S, Prevost AT, Fanshawe T, et al. Efficacy of a theory-based behavioural intervention to increase physical activity in an at-risk group in primary care (ProActive UK): a randomised trial. Lancet. 2008;371:41-8. [PMID: 18177774]
  52. Williams K, Prevost AT, Griffin S, Hardeman W, Hollingworth W, Spiegelhalter D, et al. The ProActive trial protocol - a randomised controlled trial of the efficacy of a family-based, domiciliary intervention programme to increase physical activity among individuals at high risk of diabetes [ISRCTN61323766]. BMC Public Health. 2004;4:48. [PMID: 15491494]
  53. Kolt GS, Schofield GM, Kerse N, Garrett N, Oliver M. Effect of telephone counseling on physical activity for low-active older people in primary care: a randomized, controlled trial. J Am Geriatr Soc. 2007;55:986-92. [PMID: 17608869]
  54. Lawton BA, Rose SB, Elley CR, Dowell AC, Fenton A, Moyes SA. Exercise on prescription for women aged 40-74 recruited through primary care: two year randomised controlled trial. BMJ. 2008;337:a2509. [PMID: 19074218]
  55. Marcus BH, Napolitano MA, King AC, Lewis BA, Whiteley JA, Albrecht A, et al. Telephone versus print delivery of an individualized motivationally tailored physical activity intervention: Project STRIDE. Health Psychol. 2007;26: 401-9. [PMID: 17605559]
  56. Marshall AL, Bauman AE, Owen N, Booth ML, Crawford D, Marcus BH. Population-based randomized controlled trial of a stage-targeted physical activity intervention. Ann Behav Med. 2003;25:194-202. [PMID: 12763714]
  57. Martinson BC, Crain AL, Sherwood NE, Hayes M, Pronk NP, O'Connor PJ. Maintaining physical activity among older adults: six-month outcomes of the Keep Active Minnesota randomized controlled trial. Prev Med. 2008;46:111-9. [PMID: 17904629]
  58. Sherwood NE, Martinson BC, Crain AL, Hayes MG, Pronk NP, O'Connor PJ. A new approach to physical activity maintenance: rationale, design, and baseline data from the Keep Active Minnesota Trial. BMC Geriatr. 2008;8:17. [PMID: 18655709]
  59. Morey MC, Peterson MJ, Pieper CF, Sloane R, Crowley GM, Cowper PA, et al. The Veterans Learning to Improve Fitness and Function in Elders Study: a randomized trial of primary care-based physical activity counseling for older men. J Am Geriatr Soc. 2009;57:1166-74. [PMID: 19467149]
  60. Morey MC, Peterson MJ, Pieper CF, Sloane R, Crowley GM, Cowper P, et al. Project LIFE—Learning to Improve Fitness and Function in Elders: methods, design, and baseline characteristics of randomized trial. J Rehabil Res Dev. 2008;45:31-42. [PMID: 18566924]
  61. Napolitano MA, Whiteley JA, Papandonatos G, Dutton G, Farrell NC, Albrecht A, et al. Outcomes from the Women's Wellness Project: a community-focused physical activity trial for women. Prev Med. 2006;43:447-53. [PMID: 16919322]
  62. Dutton GR, Napolitano MA, Whiteley JA, Marcus BH. Is physical activity a gateway behavior for diet? Findings from a physical activity trial. Prev Med. 2008;46:216-21. [PMID: 18234327]
  63. Norris SL, Grothaus LC, Buchner DM, Pratt M. Effectiveness of physician-based assessment and counseling for exercise in a staff model HMO. Prev Med. 2000;30:513-23. [PMID: 10901494]
  64. Pinto BM, Goldstein MG, Ashba J, Sciamanna CN, Jette A. Randomized controlled trial of physical activity counseling for older primary care patients. Am J Prev Med. 2005;29:247-55. [PMID: 16242586]
  65. Stensel DJ, Brooke-Wavell K, Hardman AE, Jones PR, Norgan NG. The influence of a 1-year programme of brisk walking on endurance fitness and body composition in previously sedentary men aged 42-59 years. Eur J Appl Physiol Occup Physiol. 1994;68:531-7. [PMID: 7957147]
  66. Stewart AL, Verboncoeur CJ, McLellan BY, Gillis DE, Rush S, Mills KM, et al. Physical activity outcomes of CHAMPS II: a physical activity promotion program for older adults. J Gerontol A Biol Sci Med Sci. 2001;56:M465-70. [PMID: 11487597]
  67. Yates T, Davies M, Gorely T, Bull F, Troughton J, Mandalian P, et al. Twelve-month follow-up from the PREPARE (Prediabetes Risk Education and Physical Activity Recommendation and Encouragement) programme study: a randomized controlled trial: A47 (P427) [Poster]. Diabet Med. 2009;26:17.
  68. Yates T, Davies M, Gorely T, Bull F, Khunti K. Rationale, design and baseline data from the Pre-diabetes Risk Education and Physical Activity Recommendation and Encouragement (PREPARE) programme study: a randomized controlled trial. Patient Educ Couns. 2008;73:264-71. [PMID: 18653305]
  69. Connell CM, Janevic MR. Effects of a telephone-based exercise intervention for dementia caregiving wives: a randomized controlled trial. J Appl Gerontol. 2009;28:171-94.
  70. Pekmezi DW, Neighbors CJ, Lee CS, Gans KM, Bock BC, Morrow KM, et al. A culturally adapted physical activity intervention for Latinas: a randomized controlled trial. Am J Prev Med. 2009;37:495-500. [PMID: 19944914]
  71. Martinson BC, Sherwood NE, Crain AL, Hayes MG, King AC, Pronk NP, et al. Maintaining physical activity among older adults: 24-month outcomes of the Keep Active Minnesota randomized controlled trial. Prev Med. 2010;51:37-44. [PMID: 20382179]
  72. Anderson JW, Garrity TF, Wood CL, Whitis SE, Smith BM, Oeltgen PR. Prospective, randomized, controlled comparison of the effects of low-fat and low-fat plus high-fiber diets on serum lipid concentrations. Am J Clin Nutr. 1992;56:887-94. [PMID: 1329482]
  73. Baron JA, Gleason R, Crowe B, Mann JI. Preliminary trial of the effect of general practice based nutritional advice. Br J Gen Pract. 1990;40:137-41. [PMID: 2115348]
  74. Beresford SA, Curry SJ, Kristal AR, Lazovich D, Feng Z, Wagner EH. A dietary intervention in primary care practice: the Eating Patterns Study. Am J Public Health. 1997;87:610-6. [PMID: 9146440]
  75. Bernstein A, Nelson ME, Tucker KL, Layne J, Johnson E, Nuernberger A, et al. A home-based nutrition intervention to increase consumption of fruits, vegetables, and calcium-rich foods in community dwelling elders. J Am Diet Assoc. 2002;102:1421-7. [PMID: 12396159]
  76. Brekke HK, Jansson PA, Lenner RA. Long-term (1- and 2-year) effects of lifestyle intervention in type 2 diabetes relatives. Diabetes Res Clin Pract. 2005; 70:225-34. [PMID: 15885845]
  77. Carpenter RA, Finley C, Barlow CE. Pilot test of a behavioral skill building intervention to improve overall diet quality. J Nutr Educ Behav. 2004;36:20-4. [PMID: 14756978]
  78. Coates RJ, Bowen DJ, Kristal AR, Feng Z, Oberman A, Hall WD, et al. The Women's Health Trial Feasibility Study in Minority Populations: changes in dietary intakes. Am J Epidemiol. 1999;149:1104-12. [PMID: 10369504]
  79. Bowen D, Clifford CK, Coates R, Evans M, Feng Z, Fouad M, et al. The Women's Health Trial Feasibility Study in Minority Populations: design and baseline descriptions. Ann Epidemiol. 1996;6:507-19. [PMID: 8978881]
  80. Hall WD, Feng Z, George VA, Lewis CE, Oberman A, Huber M, et al; Women's Health Trial: Feasibility Study in Minority Populations. Low-fat diet: effect on anthropometrics, blood pressure, glucose, and insulin in older women. Ethn Dis. 2003;13:337-43. [PMID: 12894958]
  81. Fries E, Edinboro P, McClish D, Manion L, Bowen D, Beresford SA, et al. Randomized trial of a low-intensity dietary intervention in rural residents: the Rural Physician Cancer Prevention Project. Am J Prev Med. 2005;28:162-8. [PMID: 15710271]
  82. Hypertension Prevention Trial Research Group. The Hypertension Prevention Trial: three-year effects of dietary changes on blood pressure. Arch Intern Med. 1990;150:153-62. [PMID: 2404477]
  83. Shah M, Jeffery RW, Laing B, Savre SG, Van Natta M, Strickland D. Hypertension Prevention Trial (HPT): food pattern changes resulting from intervention on sodium, potassium, and energy intake. Hypertension Prevention Trial Research Group. J Am Diet Assoc. 1990;90:69-76. [PMID: 2404050]
  84. Meinert CL, Borhani NO, Langford HG. Design, methods, and rationale in the Hypertension Prevention Trial. Hypertension Prevention Trial Research Group. Control Clin Trials. 1989;10:1S-29S. [PMID: 2680271]
  85. John JH, Ziebland S, Yudkin P, Roe LS, Neil HA; Oxford Fruit and Vegetable Study Group. Effects of fruit and vegetable consumption on plasma antioxidant concentrations and blood pressure: a randomised controlled trial. Lancet. 2002;359:1969-74. [PMID: 12076551]
  86. Kristal AR, Curry SJ, Shattuck AL, Feng Z, Li S. A randomized trial of a tailored, self-help dietary intervention: the Puget Sound Eating Patterns study. Prev Med. 2000;31:380-9. [PMID: 11006063]
  87. Lutz SF, Ammerman AS, Atwood JR, Campbell MK, DeVellis RF, Rosamond WD. Innovative newsletter interventions improve fruit and vegetable consumption in healthy adults. J Am Diet Assoc. 1999;99:705-9. [PMID: 10361533]
  88. Prochaska JO, Velicer WF, Redding C, Rossi JS, Goldstein M, DePue J, et al. Stage-based expert systems to guide a population of primary care patients to quit smoking, eat healthier, prevent skin cancer, and receive regular mammograms. Prev Med. 2005;41:406-16. [PMID: 15896835]
  89. Roderick P, Ruddock V, Hunt P, Miller G. A randomized trial to evaluate the effectiveness of dietary advice by practice nurses in lowering diet-related coronary heart disease risk. Br J Gen Pract. 1997;47:7-12. [PMID: 9115804]
  90. Sacerdote C, Fiorini L, Rosato R, Audenino M, Valpreda M, Vineis P. Randomized controlled trial: effect of nutritional counselling in general practice. Int J Epidemiol. 2006;35:409-15. [PMID: 16157616]
  91. Stefanick ML, Mackey S, Sheehan M, Ellsworth N, Haskell WL, Wood PD. Effects of diet and exercise in men and postmenopausal women with low levels of HDL cholesterol and high levels of LDL cholesterol. N Engl J Med. 1998;339:12-20. [PMID: 9647874]
  92. Stevens VJ, Glasgow RE, Toobert DJ, Karanja N, Smith KS. One-year results from a brief, computer-assisted intervention to decrease consumption of fat and increase consumption of fruits and vegetables. Prev Med. 2003;36:594-600. [PMID: 12689805]
  93. The effects of nonpharmacologic interventions on blood pressure of persons with high normal levels. Results of the Trials of Hypertension Prevention, Phase I. JAMA. 1992;267:1213-20. [PMID: 1586398]
  94. Kumanyika SK, Hebert PR, Cutler JA, Lasser VI, Sugars CP, Steffen-Batey L, et al. Feasibility and efficacy of sodium reduction in the Trials of Hypertension Prevention, phase I. Trials of Hypertension Prevention Collaborative Research Group. Hypertension. 1993;22:502-12. [PMID: 8406655]
  95. Satterfield S, Cutler JA, Langford HG, Applegate WB, Borhani NO, Brittain E, et al. Trials of hypertension prevention. Phase I design. Ann Epidemiol. 1991;1:455-71. [PMID: 1669525]
  96. The Trials of Hypertension Prevention Collaborative Research Group. Effects of weight loss and sodium reduction intervention on blood pressure and hypertension incidence in overweight people with high-normal blood pressure. The Trials of Hypertension Prevention, phase II. Arch Intern Med. 1997;157: 657-67. [PMID: 9080920]
  97. Hebert PR, Bolt RJ, Borhani NO, Cook NR, Cohen JD, Cutler JA, et al. Design of a multicenter trial to evaluate long-term life-style intervention in adults with high-normal blood pressure levels. Trials of Hypertension Prevention (phase II). Trials of Hypertension Prevention (TOHP) Collaborative Research Group. Ann Epidemiol. 1995;5:130-9. [PMID: 7795831]
  98. Kumanyika SK, Cook NR, Cutler JA, Belden L, Brewer A, Cohen JD, et al; Trials of Hypertension Prevention Collaborative Research Group. Sodium reduction for hypertension prevention in overweight adults: further results from the Trials of Hypertension Prevention Phase II. J Hum Hypertens. 2005;19:33-45. [PMID: 15372064]
  99. Tinker LF, Bonds DE, Margolis KL, Manson JE, Howard BV, Larson J, et al; Women's Health Initiative. Low-fat dietary pattern and risk of treated diabetes mellitus in postmenopausal women: the Women's Health Initiative randomized controlled dietary modification trial. Arch Intern Med. 2008;168:1500-11. [PMID: 18663162]
  100. Prentice RL, Caan B, Chlebowski RT, Patterson R, Kuller LH, Ockene JK, et al. Low-fat dietary pattern and risk of invasive breast cancer: the Women's Health Initiative Randomized Controlled Dietary Modification Trial. JAMA. 2006;295:629-42. [PMID: 16467232]
  101. Howard BV, Van Horn L, Hsia J, Manson JE, Stefanick ML, Wassertheil-Smoller S, et al. Low-fat dietary pattern and risk of cardiovascular disease: the Women's Health Initiative Randomized Controlled Dietary Modification Trial. JAMA. 2006;295:655-66. [PMID: 16467234]
  102. The Women's Health Initiative Study Group. Design of the Women's Health Initiative clinical trial and observational study. Control Clin Trials. 1998; 19:61-109. [PMID: 9492970]
  103. Watanabe M, Yamaoka K, Yokotsuka M, Tango T. Randomized controlled trial of a new dietary education program to prevent type 2 diabetes in a high-risk group of Japanese male workers. Diabetes Care. 2003;26:3209-14. [PMID: 14633803]
  104. Aldana SG, Greenlaw RL, Diehl HA, Salberg A, Merrill RM, Ohmine S, et al. The behavioral and clinical effects of therapeutic lifestyle change on middle-aged adults. Prev Chronic Dis. 2006;3:A05. [PMID: 16356358]
  105. Aldana SG, Greenlaw RL, Diehl HA, Salberg A, Merrill RM, Ohmine S, et al. Effects of an intensive diet and physical activity modification program on the health risks of adults. J Am Diet Assoc. 2005;105:371-81. [PMID: 15746824]
  106. Babazono A, Kame C, Ishihara R, Yamamoto E, Hillman AL. Patient-motivated prevention of lifestyle-related disease in Japan: A randomized, controlled clinical trial. Disease Management & Health Outcomes. 2007;15:119-26.
  107. Brekke HK, Sunesson A, Axelsen M, Lenner RA. Attitudes and barriers to dietary advice aimed at reducing risk of type 2 diabetes in first-degree relatives of patients with type 2 diabetes. J Hum Nutr Diet. 2004;17:513-21. [PMID: 15546428]
  108. Eakin EG, Bull SS, Riley KM, Reeves MM, McLaughlin P, Gutierrez S. Resources for health: a primary-care-based diet and physical activity intervention targeting urban Latinos with multiple chronic conditions. Health Psychol. 2007; 26:392-400. [PMID: 17605558]
  109. Edelman D, Oddone EZ, Liebowitz RS, Yancy WS Jr, Olsen MK, Jeffreys AS, et al. A multidimensional integrative medicine intervention to improve cardiovascular risk. J Gen Intern Med. 2006;21:728-34. [PMID: 16808774]
  110. Franko DL, Cousineau TM, Trant M, Green TC, Rancourt D, Thompson D, et al. Motivation, self-efficacy, physical activity and nutrition in college students: randomized controlled trial of an internet-based education program. Prev Med. 2008;47:369-77. [PMID: 18639581]
  111. Hardcastle S, Taylor A, Bailey M, Castle R. A randomised controlled trial on the effectiveness of a primary health care based counselling intervention on physical activity, diet and CHD risk factors. Patient Educ Couns. 2008;70:31-9. [PMID: 17997263]
  112. Oldroyd JC, Unwin NC, White M, Mathers JC, Alberti KG. Randomised controlled trial evaluating lifestyle interventions in people with impaired glucose tolerance. Diabetes Res Clin Pract. 2006;72:117-27. [PMID: 16297488]
  113. Hivert MF, Langlois MF, Bérard P, Cuerrier JP, Carpentier AC. Prevention of weight gain in young adults through a seminar-based intervention program. Int J Obes (Lond). 2007;31:1262-9. [PMID: 17356531]
  114. Jeffery RW, French SA. Preventing weight gain in adults: the pound of prevention study. Am J Public Health. 1999;89:747-51. [PMID: 10224988]
  115. Keyserling TC, Samuel Hodge CD, Jilcott SB, Johnston LF, Garcia BA, Gizlice Z, et al. Randomized trial of a clinic-based, community-supported, lifestyle intervention to improve physical activity and diet: the North Carolina enhanced WISEWOMAN project. Prev Med. 2008;46:499-510. [PMID: 18394692]
  116. Mosca L, Mochari H, Liao M, Christian AH, Edelman DJ, Aggarwal B, et al. A novel family-based intervention trial to improve heart health: FIT Heart: results of a randomized controlled trial. Circ Cardiovasc Qual Outcomes. 2008; 1:98-106. [PMID: 20031796]
  117. Oldroyd JC, Unwin NC, White M, Imrie K, Mathers JC, Alberti KG. Randomised controlled trial evaluating the effectiveness of behavioural interventions to modify cardiovascular risk factors in men and women with impaired glucose tolerance: outcomes at 6 months. Diabetes Res Clin Pract. 2001;52:29-43. [PMID: 11182214]
  118. Simkin-Silverman LR, Wing RR, Boraz MA, Meilahn EN, Kuller LH. Maintenance of cardiovascular risk factor changes among middle-aged women in a lifestyle intervention trial. Womens Health. 1998;4:255-71. [PMID: 9787651]
  119. Simkin-Silverman L, Wing RR, Hansen DH, Klem ML, Pasagian-Macaulay AP, Meilahn EN, et al. Prevention of cardiovascular risk factor elevations in healthy premenopausal women. Prev Med. 1995;24:509-17. [PMID: 8524727]
  120. Simkin-Silverman LR, Wing RR, Boraz MA, Kuller LH. Lifestyle intervention can prevent weight gain during menopause: results from a 5-year randomized clinical trial. Ann Behav Med. 2003;26:212-20. [PMID: 14644697]
  121. Thompson JL, Allen P, Helitzer DL, Qualls C, Whyte AN, Wolfe VK, et al. Reducing diabetes risk in American Indian women. Am J Prev Med. 2008; 34:192-201. [PMID: 18312806]
  122. Herman C, Thompson J, Wolfe V, Wilson N, Whyte A, Perez G, et al. Six-month results from a healthy lifestyles diabetes primary prevention program among urban Native American women. Presented at: American Public Health Association 134th Annual Meeting and Exposition; 4 November 2006; Boston, MA.
  123. Allen P, Thompson JL, Herman CJ, Whyte AN, Wolfe VK, Qualls C, et al. Impact of periodic follow-up testing among urban American Indian women with impaired fasting glucose. Prev Chronic Dis. 2008;5:A76. [PMID: 18558026]
  124. Vandelanotte C, De Bourdeaudhuij I, Sallis JF, Spittaels H, Brug J. Efficacy of sequential or simultaneous interactive computer-tailored interventions for increasing physical activity and decreasing fat intake. Ann Behav Med. 2005;29: 138-46. [PMID: 15823787]
  125. Wister A, Loewen N, Kennedy-Symonds H, McGowan B, McCoy B, Singer J. One-year follow-up of a therapeutic lifestyle intervention targeting cardiovascular disease risk. CMAJ. 2007;177:859-65. [PMID: 17923653]
  126. Albert CM, Mittleman MA, Chae CU, Lee IM, Hennekens CH, Manson JE. Triggering of sudden death from cardiac causes by vigorous exertion. N Engl J Med. 2000;343:1355-61. [PMID: 11070099]
  127. Giri S, Thompson PD, Kiernan FJ, Clive J, Fram DB, Mitchel JF, et al. Clinical and angiographic characteristics of exertion-related acute myocardial infarction. JAMA. 1999;282:1731-6. [PMID: 10568645]
  128. Hallqvist J, Möller J, Ahlbom A, Diderichsen F, Reuterwall C, de Faire U. Does heavy physical exertion trigger myocardial infarction? A case-crossover analysis nested in a population-based case-referent study. Am J Epidemiol. 2000;151: 459-67. [PMID: 10707914]
  129. Mittleman MA, Maclure M, Tofler GH, Sherwood JB, Goldberg RJ, Muller JE. Triggering of acute myocardial infarction by heavy physical exertion. Protection against triggering by regular exertion. Determinants of Myocardial Infarction Onset Study Investigators. N Engl J Med. 1993;329:1677-83. [PMID: 8232456]
  130. Siscovick DS, Weiss NS, Fletcher RH, Lasky T. The incidence of primary cardiac arrest during vigorous exercise. N Engl J Med. 1984;311:874-7. [PMID: 6472399]
  131. von Klot S, Mittleman MA, Dockery DW, Heier M, Meisinger C, Hörmann A, et al. Intensity of physical exertion and triggering of myocardial infarction: a case-crossover study. Eur Heart J. 2008;29:1881-8. [PMID: 18534976]
  132. Willich SN, Lewis M, Löwel H, Arntz HR, Schubert F, Schröder R. Physical exertion as a trigger of acute myocardial infarction. Triggers and Mechanisms of Myocardial Infarction Study Group. N Engl J Med. 1993;329:1684-90. [PMID: 8232457]
  133. Yates T, Davies M, Gorely T, Bull F, Khunti K. Effectiveness of a pragmatic education program designed to promote walking activity in individuals with impaired glucose tolerance: a randomized controlled trial. Diabetes Care. 2009;32:1404-10. [PMID: 19602539]
  134. Moore TJ, Vollmer WM, Appel LJ, Sacks FM, Svetkey LP, Vogt TM, et al. Effect of dietary patterns on ambulatory blood pressure: results from the Dietary Approaches to Stop Hypertension (DASH) Trial. DASH Collaborative Research Group. Hypertension. 1999;34:472-7. [PMID: 10489396]
  135. Sacks FM, Svetkey LP, Vollmer WM, Appel LJ, Bray GA, Harsha D, et al; DASH-Sodium Collaborative Research Group. Effects on blood pressure of reduced dietary sodium and the Dietary Approaches to Stop Hypertension (DASH) diet. DASH-Sodium Collaborative Research Group. N Engl J Med. 2001;344:3-10. [PMID: 11136953]
  136. MacMahon S, Peto R, Cutler J, Collins R, Sorlie P, Neaton J, et al. Blood pressure, stroke, and coronary heart disease. Part 1, Prolonged differences in blood pressure: prospective observational studies corrected for the regression dilution bias. Lancet. 1990;335:765-74. [PMID: 1969518]
  137. Cook NR, Cutler JA, Obarzanek E, Buring JE, Rexrode KM, Kumanyika SK, et al. Long term effects of dietary sodium reduction on cardiovascular disease outcomes: observational follow-up of the trials of hypertension prevention (TOHP). BMJ. 2007;334:885-8. [PMID: 17449506]
  138. Law MR, Wald NJ, Thompson SG. By how much and how quickly does reduction in serum cholesterol concentration lower risk of ischaemic heart disease? BMJ. 1994;308:367-72. [PMID: 8043072]
  139. Howard BV, Curb JD, Eaton CB, Kooperberg C, Ockene J, Kostis JB, et al. Low-fat dietary pattern and lipoprotein risk factors: the Women's Health Initiative Dietary Modification Trial. Am J Clin Nutr. 2010;91:860-74. [PMID: 20164311]
  140. Zaza S, Lawrence RS, Mahan CS, Fullilove M, Fleming D, Isham GJ, et al. Scope and organization of the Guide to Community Preventive Services. The Task Force on Community Preventive Services. Am J Prev Med. 2000;18: 27-34. [PMID: 10806977]
  141. Fowles ER, Sterling BS, Walker LO. Measuring dietary intake in nursing research. Can J Nurs Res. 2007;39:146-65. [PMID: 17679590]
Current as of: December 2010

Internet Citation: Final Evidence Summary: Healthy Diet and Physical Activity: Counseling for CVD Prevention in Adults. U.S. Preventive Services Task Force. August 2014.
https://www.uspreventiveservicestaskforce.org/Page/Document/final-evidence-summary27/healthy-diet-and-physical-activity-counseling-for-cvd-prevention-in-adults

USPSTF Program Office   5600 Fishers Lane, Mail Stop 06E53A, Rockville, MD 20857