in progress

Draft Research Plan

Healthy Diet, Physical Activity, and/or Weight Loss to Prevent Cardiovascular Disease in Adults: Behavioral Counseling Interventions

May 18, 2023

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.

Figure 1 is the analytic framework that depicts the three Key Questions to be addressed in the systematic review. The figure illustrates how interventions to support weight loss and weight loss maintenance may result in a reduction of all-cause and CVD mortality, CVD events, depression, and improve quality of life and functioning (KQ1). Additionally, the figure illustrates how interventions to support weight loss and weight loss maintenance may have an impact on weight outcomes, incidence and prevalence of diabetes mellitus, hypertension, and dyslipidemia, and may improve cardiorespiratory fitness measures (KQ2). Further, the figure depicts whether interventions to support weight loss and weight loss maintenance are associated with any harms (KQ3).

*BMI ≥25 kg/m2.
Abbreviations: BMI=body mass index; CVD=cardiovascular disease; KQ=key question; QoL=quality of life.

  1. Do primary care–relevant behavioral or pharmacotherapy weight loss and weight loss maintenance interventions for adults with higher body mass index (BMI) affect health outcomes?
  2. Do primary care–relevant behavioral or pharmacotherapy weight loss and weight loss maintenance interventions for adults with higher BMI affect weight outcomes or cardiometabolic outcomes?
  3. What are the harms associated with weight loss interventions for adults?

Contextual questions will not be systematically reviewed and are not shown in the Analytic Framework

  1. What is the association between intentional weight loss and health outcomes, including harms?
  2. What is the added value of measures of central adiposity in assessing the health risks associated with higher BMI?
  3. What are the important issues related to weight stigma and bias in the clinical setting?
  4. What is the effectiveness and comparative effectiveness and safety of bariatric procedures for weight loss?
  5. What inequities exist in relation to weight management interventions?

Health equity will be considered throughout the review using several approaches. For Key Questions, we will describe the population and intervention characteristics of the included studies to assess the degree to which the evidence is representative of diverse populations. Further, we will characterize the extent to which interventions are tailored to meet the needs of specific populations or aspects of social determinants of health more broadly. We will also analyze the benefits and harms of interventions by specific populations to the extent that this is reported in the literature for selected populations of interest. These groups include, but are not limited to, categorizations by age; racial, ethnic, and cultural identity; socioeconomic and insurance status; and presence of comorbid conditions. We will also include a contextual question to explore inequities in relation to weight management interventions in the United States. We acknowledge that the mechanisms for inequities related to weight management interventions are complex, thus this question is considered broadly.

The proposed Research Approach identifies the study characteristics and criteria that the Evidence-based Practice Center will use to search for publications and to determine whether identified studies should be included or excluded from the Evidence Review. Criteria are overarching as well as specific to each of the Key Questions.

  Include Exclude
Study aim Weight loss or weight loss maintenance
  • Healthy lifestyle counseling with no weight-related messages
  • Primary prevention of weight gain
  • Treatment of cardiovascular disease
  • Management of diabetes*
  • Treatment of cancer
Population Adults age 18 years or older selected based on higher BMI (≥25 kg/m2) or other adiposity measures (e.g., waist circumference)

Studies including or limited to individuals with additional cardiovascular disease risk factors, including hypertension, dyslipidemia, or impaired glucose metabolism; postpartum women; persons with a history of cancer are included

Studies limited to:
  • Adults with secondary causes of higher BMI, such as steroid use
  • Adults with a chronic disease for which weight loss or weight loss maintenance is part of disease management (e.g., osteoarthritis, cardiovascular disease, diabetes mellitus, polycystic ovary syndrome, nonalcoholic fatty liver disease, or sleep apnea)
  • Adults with a known chronic disease not generalizable to the primary care population (e.g., eating disorder, cancer, chronic kidney disease, severe mental illness, or cognitive impairment)
  • Adults with monogenic or syndromic obesity due to rare genetic conditions
  • Children and adolescents
  • Pregnant women
Setting Studies conducted in or recruited from primary care or a healthcare setting or that could feasibly be implemented in or referred from primary care (e.g., virtual/online interventions, telephone-based interventions, research settings, or community settings) Studies conducted in or recruited from settings not generalizable to primary care (e.g., worksites, churches, university classrooms, or institutional settings) or in a setting where the intervention could not be reproduced in primary care or within a broader health system
Interventions Interventions focused on weight loss or weight loss maintenance, including the following, alone or in combination:
  • Behavioral-based interventions (e.g., behavior modification, cognitive behavioral therapy, or health-behavior change counseling and coaching)
  • Pharmacologic interventions approved by the FDA or clinically used for weight management: orlistat, phentermine-topiramate extended release, naltrexone hydrochloride and bupropion hydrochloride, liraglutide, semaglutide, tirzepatide, and metformin
Interventions may be delivered via face-to-face contact, telephone, print materials, or technology (e.g., computer-based, text messages, or apps) and can be delivered by numerous potential interventionists, including, but not limited to, physicians, nurses, exercise specialists, dietitians, nutritionists, and behavioral health specialists
  • Surgical and nonsurgical devices and procedures (e.g., laparoscopic adjustable gastric banding, Roux-en-Y gastric bypass, or balloon system)
  • Medications that are not currently approved by the FDA for weight management (e.g., lorcaserin hydrochloride or phentermine)
  • Complementary and alternative treatments (e.g., acupuncture or hypnosis)
  • Dietary supplements intended for weight loss (e.g., chitosan or green tea extract)
  • Interventions that provide all or most of participants’ food
  • Broader community-based programs (e.g., mass media, social marketing, changes to the built environment, or legislation)
Comparisons Behavioral-based interventions vs.:  
  • No treatment (e.g., wait list/delayed intervention)
  • Usual care (usual weight loss intervention provided by study setting)
  • Minimal intervention (e.g., pamphlets or single annual session presenting information like what intervention groups receive through usual care in a primary care setting)
  • Weight-neutral healthy lifestyle intervention (i.e., diet and physical activity counseling with no weight loss message)
  • Attention control (e.g., similar format and intensity of intervention on a different content area)
Pharmacologic interventions (alone or in combination with behavioral-based interventions) vs. placebo or no medication (alone or in combination with behavioral-based interventions)
Head-to-head comparisons of different weight management interventions
Outcomes KQ 1: Health outcomes:
  • All-cause and cardiovascular disease mortality
  • Cardiovascular disease events
  • Depression
  • Quality of life or functioning

KQ 2: Intermediate outcomes:

Weight outcomes (required for inclusion) including:

  • Measured weight (e.g., kilograms or pounds) or weight status (e.g., BMI, percent overweight, or percent obese)
  • Total adiposity (e.g., dual-energy x-ray absorptiometry or underwater weighing)
  • Central adiposity (e.g., waist circumference or waist-to-hip circumference ratio

Incidence or prevalence of the following cardiometabolic conditions and measures:

  • Diabetes mellitus
  • Hypertension
  • Dyslipidemia
  • Cardiorespiratory fitness measures

KQ 3: Harms:

Any adverse treatment-related harm after initiation of the intervention, including:

  • Any adverse event or serious adverse event
  • Withdrawals or discontinuation of medication due to adverse effects
  • Unhealthy weight management efforts (e.g., using laxatives or self-induced vomiting) or eating patterns (excessive fasting, overly restrictive eating, or binging)
  • Worsening of quality of life or psychological symptoms, including increased symptoms of depression and anxiety, and body image concerns
  • Exercise-induced injury
  • Self-reported weight
  • Continuous measures of glucose, blood pressure, or lipid levels
  • Behavioral changes (e.g., physical activity or diet)
Timing of outcome assessment KQs 1, 2: ≥12 months after baseline or beginning of weight loss or weight maintenance phase

KQ 3: No minimum followup

<12 months after baseline (except for harms of pharmacotherapy)
Study design All KQs: Randomized clinical trials

KQ 3 (harms of pharmacotherapy): Large nonrandomized studies of interventions comparing concurrent exposure vs. nonexposure to medication

All other study designs
Country Studies that take place in countries categorized as “Very High” in 2021 on the Human Development Index (as defined by the United Nations Development Programme) Studies that are conducted in countries that are not categorized as “Very High” on the 2021 Human Development Index
Publication language Studies published in English Studies only published in languages other than English
Study quality Fair or good, according to study design and risk of bias criteria Poor

* Screening and treatment of diabetes is included in a separate USPSTF review and recommendation. Interventions to prevent diabetes with weight loss messages are included in this review.
The effectiveness, comparative effectiveness, and safety of bariatric weight loss procedures will be addressed in a Contextual Question.

Abbreviations: BMI=body mass index; FDA=Food and Drug Administration; KQ=key question; USPSTF=U.S. Preventive Services Task Force.