Weight Loss to Prevent Obesity-Related Morbidity and Mortality in Adults: Behavioral Interventions

The US Preventive Services Task Force (USPSTF) makes recommendations about the effectiveness of specific preventive care services for patients without obvious related signs or symptoms.

It bases its recommendations on the evidence of both the benefits and harms of the service and an assessment of the balance. The USPSTF does not consider the costs of providing a service in this assessment.

The USPSTF recognizes that clinical decisions involve more considerations than evidence alone. Clinicians should understand the evidence but individualize decision making to the specific patient or situation. Similarly, the USPSTF notes that policy and coverage decisions involve considerations in addition to the evidence of clinical benefits and harms

Importance

More than 35% of men and 40% of women in the United States are obese.^1,2 Obesity is associated with health problems such as increased risk for coronary heart disease, type 2 diabetes, various types of cancer, gallstones, and disability.^1,3-7 Obesity is also associated with an increased risk for death, particularly among adults younger than 65 years.¹ The leading causes of death among adults with obesity include ischemic heart disease, type 2 diabetes, respiratory diseases, and cancer (eg, liver, kidney, breast, endometrial, prostate, and colon cancer).^1,3,8-12

Benefits of Behavioral Counseling Interventions

The USPSTF found adequate evidence that behavior-based weight loss interventions in adults with obesity can lead to clinically significant improvements in weight status and reduced incidence of type 2 diabetes among adults with obesity and elevated plasma glucose levels. The USPSTF found adequate evidence that behavior-based weight loss maintenance interventions are associated with less weight gain after the cessation of interventions, compared with control groups. The magnitude of these benefits is moderate.

Harms of Behavioral Counseling Interventions

The USPSTF found adequate evidence to bound the harms of intensive, multicomponent behavioral interventions (ie, behavior-based weight loss and weight loss maintenance interventions) in adults with obesity as small to none, based on the absence of reported harms in the evidence and the noninvasive nature of the interventions. When direct evidence is limited, absent, or restricted to select populations or clinical scenarios, the USPSTF may place conceptual upper or lower bounds on the magnitude of benefit or harms.

USPSTF Assessment

The USPSTF concludes with moderate certainty that offering or referring adults with obesity to intensive, multicomponent behavioral interventions (ie, behavior-based weight loss and weight loss maintenance interventions) has a moderate net benefit.

Patient Population Under Consideration

This recommendation applies to adults 18 years or older. The USPSTF uses the following terms to define categories of increased BMI: “overweight” is a BMI of 25 to 29.9 and “obesity” is a BMI of 30 or higher. Obesity can be categorized as class 1 (BMI of 30.0 to 34.9), class 2 (BMI of 35.0 to 39.9), or class 3 (BMI of ≥40) (see the Table for other USPSTF recommendations related to weight).

Behavioral Counseling Interventions

Many of the effective intensive behavioral interventions considered by the USPSTF were designed to help participants achieve or maintain a 5% or greater weight loss through a combination of dietary changes and increased physical activity. The US Food and Drug Administration considers a weight loss of 5% as clinically important.¹

Most of the intensive behavioral weight loss interventions considered by the USPSTF lasted for 1 to 2 years, and the majority had 12 or more sessions in the first year.¹ One-third of the interventions had a “core” phase (ranging from 3-12 months) followed by a “support” or “maintenance” phase (ranging from 9-12 months).¹ Most behavioral interventions encouraged self-monitoring of weight and provided tools to support weight loss or weight loss maintenance (eg, pedometers, food scales, or exercise videos).¹ Similar behavior change techniques and weight loss messages were used across the trials.¹ Some trials provided interventions modeled after the Diabetes Prevention Program lifestyle intervention for use in a primary care or community setting.¹ Study heterogeneity, trial quality, and differences in populations and settings made it difficult to identify the most effective intervention characteristics (eg, number of sessions, in-person vs remote sessions, or group- vs individual-based).¹ Benefits may depend on tailoring interventions to social, environmental, and individual factors.

Interventionists varied across the trials, and interventions included varied interactions with a primary care clinician. Primary care clinician involvement ranged from limited interactions with participants in interventions conducted by other practitioners or individuals (ie, group-based interventions conducted by lifestyle coaches or registered dietitians) to reinforcing intervention messages through brief counseling sessions.¹ Few interventions included a primary care clinician as the primary interventionist over 3 to 12 months of individual counseling. In the trials not involving a primary care clinician, the interventionists were highly diverse and included behavioral therapists, psychologists, registered dietitians, exercise physiologists, lifestyle coaches, and other staff. The majority of the trials focused on individual participants, but a few interventions invited family members to participate.¹

Trials used various delivery methods (group, individual, mixed, and technology- or print-based). Group-based interventions ranged from 8 group sessions over 2.5 months to weekly group sessions over 1 year (median, 23 total sessions in the first year). These interventions consisted of classroom-style sessions lasting 1 to 2 hours.¹ Within the group-based interventions, some trials offered supplemental support with 1 brief individual counseling session, while other trials provided referral and free access to commercially available group-based weight loss programs.

Most of the individual-based interventions provided individual counseling sessions, with or without ongoing telephone support.¹ The remaining interventions were provided remotely through telephone counseling calls (average time, 15-30 minutes) and web-based self-monitoring and support. The median number of sessions in the first year for individual-based interventions was 12.¹

Mixed interventions included comparatively equal numbers of group- and individual-based counseling sessions, with or without other forms of support (eg, telephone-, print-, or web-based). Most of these interventions took place for more than 1 year and involved more than 12 sessions (median, 23 total sessions in the first year).

Among technology-based interventions, intervention components included computer- or web-based intervention modules,¹ web-based self-monitoring, mobile phone–based text messages, smartphone applications, social networking platforms, or DVD learning. Only 1 trial delivered its intervention through print-based tailored materials.¹

Rates of participant adherence were generally high.¹ More than two-thirds of study participants completed interventions. In addition, all study participants completed more than two-thirds of the intervention. Participation rates did decline over time.¹

Behavior-based weight loss maintenance trials were designed to maintain weight loss by continuing dietary changes and physical activity.¹ Interventions included group interventions, technology-based individual counseling sessions, or a combination of individual and group counseling. Most weight loss maintenance interventions lasted for 12 to 18 months; the majority of interventions had more than 12 sessions in the first year.¹ Intervention components focused on nutrition, physical activity, self-monitoring, identifying barriers, problem solving, peer support, and relapse prevention.¹ Participants used tools such as food diaries and pedometers to help maintain weight loss.¹

Interventions that combined pharmacotherapy with behavioral interventions reported greater weight loss and weight loss maintenance over 12 to 18 months compared with behavioral interventions alone.¹ However, the participants in the pharmacotherapy trials were required to meet highly selective inclusion criteria, including adherence to taking medications and meeting weight loss goals before enrollment. These trials also had high attrition.¹ Therefore, it is unclear how well patients tolerate these medications and whether the findings from these trials are applicable to the general US primary care population. In addition, data were lacking about the maintenance of improvement after discontinuation of pharmacotherapy.¹ As a result, the USPSTF encourages clinicians to promote behavioral interventions as the primary focus of effective interventions for weight loss in adults.

Additional Approaches to Prevention

The USPSTF has made recommendations on screening for abnormal blood glucose levels and type 2 diabetes,¹³ screening for high blood pressure,¹⁴ statin use in persons at risk for cardiovascular disease,¹⁵ counseling for tobacco smoking cessation,¹⁶ aspirin use in certain persons for prevention of cardiovascular disease,¹⁷ and behavioral counseling interventions to promote a healthful diet and physical activity for cardiovascular disease prevention in adults with and without common risk factors^18,19 (Table). The USPSTF recommends that clinicians screen for obesity in children 6 years or older and offer or refer them to a comprehensive, intensive behavioral intervention (B recommendation).²⁰

Useful Resources

The Community Preventive Services Task Force recommends multicomponent interventions that use technology-supported coaching or counseling to help adults lose weight and maintain weight loss.²¹

Research Needs and Gaps

Further research is needed to examine the effects of interventions for obesity on longer-term weight and health outcomes (eg, cardiovascular outcomes), including data on important subpopulations (eg, older adults, racial/ethnic groups, or persons who are overweight). Psychosocial, quality of life, and patient-centered outcomes should continue to be evaluated in future studies. Well-designed pragmatic trials and improved reporting of intervention characteristics to enable evaluation and dissemination of interventions in primary care settings are needed. Future research is needed on factors (eg, genetics or untreated medical or psychological conditions) that may be barriers to weight loss during behavioral interventions. Trials are needed that examine whether interventions that focus on both weight loss and support of persons living with obesity improve patient-centered outcomes. Comparative effectiveness trials would provide more evidence about the components of effective interventions.

Burden of Disease

From 2013 to 2014, the prevalence of obesity in the United States was greater than 35% among men and 40% among women.² One in 13 Americans has a BMI higher than 40 (class 3 obesity).²² According to 2011-2014 data, the age-adjusted prevalence of persons who are overweight or obese is 72.8% among men and 66.2% among women.²³

The prevalence of overweight and obesity varies across race/ethnicity. The age-adjusted prevalence of obesity is higher among non-Hispanic black (57.2%) and Hispanic (46.9%) women than among non-Hispanic white (38.2%) women. Among men, obesity prevalence is 38.0% in non-Hispanic black, 37.9% in Hispanic, and 34.7% in non-Hispanic white men.²⁴ Obesity rates among Asian Americans are lower than among other racial/ethnic groups (12.6% and 12.4% in men and women, respectively). However, Asian Americans have higher body fat at a given BMI than other racial/ethnic groups. When using an adjusted cut point of greater than 25, obesity prevalence is higher among US-born Asian Americans (43%) than among non-Hispanic whites (36%).²⁵

Scope of Review

The USPSTF commissioned a systematic evidence review to update its 2012 recommendation on screening for obesity in adults.^1,26 Because screening for obesity is now part of routine clinical practice, it was not a focus of this review. The USPSTF reviewed evidence on interventions (behavioral counseling and pharmacotherapy) for weight loss or weight loss maintenance that can be provided in or referred from a primary care setting. Waist circumference may be an acceptable alternative to BMI measurement in some patient subpopulations. Surgical weight loss interventions and nonsurgical weight loss devices (eg, gastric balloons) are considered to be outside the scope of the primary care setting.

Effectiveness of Behavioral Counseling and Pharmacotherapy Interventions

The USPSTF reviewed the evidence on 4 types of interventions: behavior-based weight loss (80 trials), behavior-based weight loss maintenance (9 trials), pharmacotherapy-based weight loss (32 trials), and pharmacotherapy-based weight loss maintenance (3 trials). In the weight loss maintenance trials, patient randomization occurred after prior weight loss.¹

Behavioral Counseling Interventions

The USPSTF identified 89 behavior-based weight loss and weight loss maintenance trials, 26 of which were good quality and 63 of which were fair quality. Eighty trials focused on behavior-based weight loss interventions.¹ The majority of behavior-based weight loss intervention trials (47 trials) were conducted in the United States; other study sites included Europe (15 trials), the United Kingdom (11 trials), Japan (3 trials), Australia (2 trials), and Canada (2 trials). In more than half of the trials (40 trials), participants came from an unselected population of adults who were overweight or had obesity. In the remaining trials, enrolled participants had elevated clinical or subclinical risk of cardiovascular disease or cancer.¹ Trial sample sizes ranged from 30 to 2161. The mean baseline BMI ranged from 25 to 39.2 (median, 33.4), and the mean age ranged from 22 to 66 years (median, 50.3 years). Fourteen trials were limited to women, and 4 trials were restricted to men.¹ Eleven trials focused on specific racial/ethnic groups (eg, African American, Asian and South Asian, American Indian, or Hispanic). Socioeconomic status was not well reported in trials; however, when described, most participants were of medium to high socioeconomic status. Most trials did not stratify results by BMI or BMI category, age, race/ethnicity, or health status.¹

Although some trials included participants who were overweight, the average BMI in the majority of trials was in the obese range (median BMI, >33).¹ Therefore, the USPSTF was unable to examine the differential effects of interventions among participants who were overweight or had obesity.

Nine trials focused on behavior-based weight loss maintenance.¹ Study sites were in the United States, the United Kingdom, Finland, and Australia. In most trials (8 trials), participants came from an unselected population of adults who were overweight or had obesity. One trial enrolled participants with cardiovascular risk factors.¹ Trial sample sizes ranged from 92 to 1032. Participants were required to meet weight loss goals before enrollment. The mean BMI at enrollment ranged from 28.4 to 41.7 and the mean age ranged from 46.4 to 61.8 years (median, 49.2 years).¹ One trial was limited to women, and 1 trial was limited to men. The majority of trials did not report information regarding race/ethnicity or socioeconomic status. When this information was reported, participants were mostly white and of medium to high socioeconomic status.¹

Behavior-Based Weight Loss and Weight Loss Maintenance Interventions

Few health outcomes were identified in the behavior-based weight loss and weight loss maintenance trials (20 trials [n = 9910]). There were no significant differences in mortality between intervention and control groups (4 trials [n = 4442]). There were also no significant differences in cardiovascular events between intervention and control groups (2 trials [n = 2666]).¹ Trials that examined health-related quality of life (17 trials [n = 7120]) mostly demonstrated a lack of statistically significant differences between intervention and control groups.

Intermediate outcomes (eg, prevalence of high blood pressure or the metabolic syndrome, use of cardiovascular disease medications, or estimated 10-year risk of cardiovascular disease) were seldom reported. Effects of interventions on cardiovascular disease risk, the metabolic syndrome, hypertension or hyperlipidemia diagnoses, and medication use were mixed.

Thirteen behavior-based weight loss trials (n = 4095) evaluated incident type 2 diabetes in intervention vs control groups. Twelve of the 13 trials enrolled participants with impaired fasting glucose or increased risk for type 2 diabetes (ie, persons with a family history of diabetes or personal history of gestational diabetes or the metabolic syndrome). In the good-quality Diabetes Prevention Program trial (n = 1295), the estimated cumulative incidence of type 2 diabetes at 3 years was 14.4% vs 28.9% in the intervention vs placebo groups, respectively, and the number needed to treat to prevent 1 case of diabetes was 6.8. The good-quality Finnish Diabetes Prevention Study (n = 523) demonstrated that participants in the intervention group were significantly less likely to develop type 2 diabetes than those in the control group after 9 years (40.0% vs 54.5%, respectively; hazard ratio, 0.4 [95% CI, 0.3 to 0.7]). In the remaining trials, the differences between the intervention and control groups were not statistically significant. However, these trials were smaller and shorter than the larger trials. Pooling the trials (9 studies; n = 3140) showed a significant reduction in the risk of developing type 2 diabetes over 1 to 9 years (pooled risk ratio, 0.67 [95% CI, 0.51 to 0.89]; I² = 49.2%).^1,27-29

Participants in behavior-based weight loss intervention groups demonstrated greater weight loss and decreased waist circumference compared with those in control groups at 24 months of follow-up. At 12 to 18 months, pooled results showed greater weight loss among intervention participants (−2.39 kg [−5.3 lb] [95% CI, −2.86 to −1.93]; 67 trials [n = 22,065]; I² = 90.0%).¹ The mean absolute change in weight ranged from −0.5 kg (−1.1 lb) to −9.3 kg (−20.5 lb) among intervention groups and from 1.4 kg (3.1 lb) to −5.6 (−12.3 lb) among control groups. At 12 to 18 months, intervention participants were more likely to lose 5% of their initial weight compared with control participants (risk ratio, 1.94 [95% CI, 1.70 to 2.22]; 38 trials [n = 12,231]; I² = 67.2%; number needed to treat = 8).¹ Participants in weight loss maintenance interventions had less weight gain compared with participants in control groups (pooled mean difference in weight change, −1.59 kg [−3.5 lb] [95% CI, −2.38 to −0.79]; 8 studies [n = 1408]; I² = 26.8%).¹

Pharmacotherapy-Based Weight Loss and Weight Loss Maintenance Interventions

Pharmacotherapy trials evaluated liraglutide (4 trials), lorcaserin (4 trials), naltrexone and bupropion (3 trials), orlistat (21 trials), and phentermine-topiramate (3 trials) in combination with behavioral counseling.¹ The review of pharmacotherapy-based trials focused on trials that used dosages approved by the US Food and Drug Administration. All trials were fair quality. Across all trials, both study groups (ie, placebo and pharmacotherapy groups) received the same behavioral interventions. The trials were conducted in the United States, Europe, Australia, New Zealand, and other regions. Participant characteristics were similar to those in the behavioral intervention trials. Many trials required participants to demonstrate medication adherence, meet weight loss goals before enrollment, or both. The more narrowly defined inclusion criteria of these trials resulted in more selective populations enrolled as study participants.¹ Meta-analyses could not be conducted because of the few number of trials for each drug or variability in outcome reporting.¹ The rate of trial completion in the medication and placebo groups ranged from 10% to 93% (most ranged from 50% to 70%).¹

Ten trials of pharmacotherapy-based interventions (n = 13,145) examined quality of life outcomes.¹ Many trials showed improvement in obesity-specific quality of life measures among participants receiving pharmacotherapy compared with placebo. However, these outcomes are difficult to interpret because of high dropout rates (≥35% in half of the included trials), the small differences between study groups, and the unclear clinical significance of improved quality of life scores.¹ Trials that reported cardiovascular events found few events in any group (2 trials [n = 6210]). Pharmacotherapy-based weight loss maintenance trials did not report any health outcomes.¹

Limited data from 4 trials examined weight loss medication and incident diabetes (n = 9763) and found a reduced risk of diabetes. However, these trials were limited by high dropout rates.^1,26 Other intermediate outcomes (use of lipid-lowering and antihypertensive medications, prevalence of the metabolic syndrome, and 10-year risk of cardiovascular disease) were sparsely reported and had mixed findings.¹

At 12 to 18 months, participants in pharmacotherapy-based weight loss trials (32 trials) had more weight loss compared with placebo groups (mean or least squares mean difference in weight change, −1.0 kg [−2.2 lb] to −5.8 kg [−12.8 lb]).^1,26 Participants also experienced a greater decrease in waist circumference and a greater likelihood of losing 5% of their initial weight compared with placebo groups. Three pharmacotherapy-based weight loss maintenance trials showed that participants receiving the intervention had better weight loss maintenance compared with placebo groups over 12 to 36 months (mean difference, −0.6 to −3.5 kg).¹

Potential Harms of Behavioral Counseling Interventions

Behavior-Based Weight Loss and Weight Loss Maintenance Interventions

The USPSTF looked for evidence on potential harms of behavioral weight-loss interventions, including increased risk for fractures, serious injuries resulting from increased physical activity, and an increased risk for eating disorders, weight stigma, and weight fluctuation. Thirty trials (n = 12,824) examined the harms of behavior-based weight loss and weight loss maintenance interventions. Fifteen trials were good quality and 15 trials were fair quality. Intervention harms were sparsely reported. Overall, the trials showed no serious harms, and most trials observed no difference in the rate of adverse events between intervention and control groups. Three trials demonstrated mixed results for musculoskeletal problems.

Pharmacotherapy-Based Weight Loss and Weight Loss Maintenance Interventions

Pharmacological agents for weight loss have multiple potential harms, including anxiety, pancreatitis, and gastrointestinal symptoms with liraglutide; dizziness and cognitive impairment with lorcaserin; nausea, constipation, headache, and dry mouth with naltrexone and bupropion; cramps, flatus, fecal incontinence, and oily spotting with orlistat; and mood disorders, elevated heart rate, and metabolic acidosis with phentermine-topiramate. These harms have not been well studied. Thirty-three trials and 2 observational studies (n = 239,428), all fair quality, assessed the harms of pharmacotherapy-based weight loss and weight loss maintenance interventions. Serious adverse events were uncommon and similar between groups.¹ Adverse event rates were high in both intervention and placebo groups by 12 months, with 80% to 96% of participants experiencing an adverse event in the medication group compared with 63% to 94% in the placebo group. The higher rate of adverse events in the medication groups resulted in higher dropout rates than in the placebo groups.¹ Other limitations of the pharmacotherapy studies include a small number of trials for each medication, methodological variability, missing data, poor follow-up, and limited applicability (participants met narrowly defined inclusion criteria).²⁶

Estimate of Magnitude of Net Benefit

The USPSTF found adequate evidence that intensive, multicomponent behavioral interventions in adults with obesity can lead to clinically significant improvements in weight status and reduce the incidence of type 2 diabetes among adults with obesity and elevated plasma glucose levels; these interventions are of moderate benefit. The USPSTF found adequate evidence that behavior-based weight loss maintenance interventions are of moderate benefit. The USPSTF found adequate evidence that the harms of intensive, multicomponent behavioral interventions (including weight loss maintenance interventions) in adults with obesity are small to none.

Therefore, the USPSTF concludes with moderate certainty that offering or referring adults with obesity to intensive behavioral interventions or behavior-based weight loss maintenance interventions has a moderate net benefit.

How Does Evidence Fit With Biological Understanding?

Various environmental and genetic factors play an important role in the development of obesity. After obesity has developed, an individual’s biological mechanisms work to sustain the body’s weight gain.³⁰ Changes in neuronal signaling decrease satiety and perceptions of the amount of food eaten. As a result, weight loss can be challenging.³¹ Weight gain can progressively increase over the life span of an adult until later in life. Weight declines after the sixth decade of life.³² An increasing BMI may lead to increased long-term health risks. Losing weight may reduce the risk for illness and mortality and improve overall health.

Response to Public Comment

A draft version of this recommendation statement was posted for public comment on the USPSTF website from February 20 to March 19, 2018. In response to comments, the USPSTF expanded the description of behavioral counseling interventions in the Clinical Considerations section. In the Discussion section, the USPSTF clarified why persons who are overweight were not included in the recommendation statement, expanded the description on harms of behavioral counseling interventions and pharmacotherapy, and added the limitations of pharmacotherapy trials.

This recommendation updates the 2012 USPSTF recommendation statement on screening for obesity in adults (B recommendation).³³

The Canadian Task Force on Preventive Health Care recommends screening for obesity in adults with BMI at primary care visits.³⁴ The Academy of Nutrition and Dietetics, American College of Cardiology, American Heart Association, and the Obesity Society recommend screening for obesity in adults with BMI and waist circumference.^35,36 The American Association of Clinical Endocrinologists, American College of Endocrinology, and the National Institute for Health and Care Excellence recommend screening for obesity with BMI and using waist circumference as a supplement in adults with a BMI higher than 35.^37,38 The American Academy of Family Physicians recommends screening for obesity in all adults and offering or referring patients with a BMI of 30 or higher to intensive, multicomponent behavioral interventions.³⁹

The US Preventive Services Task Force (USPSTF) members include the following individuals: Susan J. Curry, PhD (University of Iowa, Iowa City); Alex H. Krist, MD, MPH (Fairfax Family Practice Residency, Fairfax, Virginia, and Virginia Commonwealth University, Richmond); Douglas K. Owens, MD, MS (Veterans Affairs Palo Alto Health Care System, Palo Alto, California, and Stanford University, Stanford, California); Michael J. Barry, MD (Harvard Medical School, Boston, Massachusetts); Aaron B. Caughey, MD, PhD (Oregon Health & Science University, Portland); Karina W. Davidson, PhD, MASc (Columbia University, New York, New York); Chyke A. Doubeni, MD, MPH (University of Pennsylvania, Philadelphia); John W. Epling Jr, MD, MSEd (Virginia Tech Carilion School of Medicine, Roanoke); David C. Grossman, MD, MPH (Kaiser Permanente Washington Health Research Institute, Seattle); Alex R. Kemper, MD, MPH, MS (Nationwide Children’s Hospital, Columbus, Ohio); Martha Kubik, PhD, RN (Temple University, Philadelphia, Pennsylvania); C. Seth Landefeld, MD (University of Alabama at Birmingham); Carol M. Mangione, MD, MSPH (University of California, Los Angeles); Maureen G. Phipps, MD, MPH (Brown University, Providence, Rhode Island); Michael Silverstein, MD, MPH (Boston University, Boston, Massachusetts); Melissa A. Simon, MD, MPH (Northwestern University, Evanston, Illinois); Chien-Wen Tseng, MD, MPH, MSEE (University of Hawaii, Honolulu, and Pacific Health Research and Education Institute, Honolulu, Hawaii); John B. Wong, MD (Tufts University School of Medicine, Boston, Massachusetts).

Conflict of Interest Disclosures: All authors have completed and submitted the ICMJE Form for Disclosure of Potential Conflicts of Interest. All members of the USPSTF receive travel reimbursement and an honorarium for participating in USPSTF meetings. No other disclosures were reported.

Funding/Support: The USPSTF is an independent, voluntary body. The US Congress mandates that the Agency for Healthcare Research and Quality (AHRQ) support the operations of the USPSTF.

Disclaimer: Recommendations made by the USPSTF are independent of the US government. They should not be construed as an official position of AHRQ or the US Department of Health and Human Services.

Copyright Notice: USPSTF recommendations are based on a rigorous review of existing peer-reviewed evidence and are intended to help primary care clinicians and patients decide together whether a preventive service is right for a patient's needs. To encourage widespread discussion, consideration, adoption, and implementation of USPSTF recommendations, AHRQ permits members of the public to reproduce, redistribute, publicly display, and incorporate USPSTF work into other materials provided that it is reproduced without any changes to the work of portions thereof, except as permitted as fair use under the US Copyright Act.

AHRQ and the US Department of Health and Human Services cannot endorse, or appear to endorse, derivative or excerpted materials, and they cannot be held liable for the content or use of adapted products that are incorporated on other Web sites. Any adaptations of these electronic documents and resources must include a disclaimer to this effect. Advertising or implied endorsement for any commercial products or services is strictly prohibited.

This work may not be reproduced, reprinted, or redistributed for a fee, nor may the work be sold for profit or incorporated into a profit-making venture without the express written permission of AHRQ. This work is subject to the restrictions of Section 1140 of the Social Security Act, 42 U.S.C. §320b-10. When parts of a recommendation statement are used or quoted, the USPSTF Web page should be cited as the source.

1. LeBlanc EL, Patnode CD, Webber EM, Redmond N, Rushkin M, O’Connor EA. Behavioral and Pharmacotherapy Weight Loss Interventions to Prevent Obesity-Related Morbidity and Mortality in Adults: An Updated Systematic Review for the US Preventive Services Task Force: Evidence Synthesis No. 168. Rockville, MD: Agency for Healthcare Research and Quality; 2018. AHRQ publication 18-05239-EF-1.
2. Ogden CL, Carroll MD, Fryar CD, Flegal KM. Prevalence of obesity among adults and youth: United States, 2011-2014. NCHS Data Brief. 2015(219):1-8.
3. Bogers RP, Bemelmans WJ, Hoogenveen RT, et al; BMI-CHD Collaboration Investigators. Association of overweight with increased risk of coronary heart disease partly independent of blood pressure and cholesterol levels: a meta-analysis of 21 cohort studies including more than 300 000 persons. Arch Intern Med. 2007;167(16):1720-8.
4. Colditz GA, Willett WC, Rotnitzky A, Manson JE. Weight gain as a risk factor for clinical diabetes mellitus in women. Ann Intern Med. 1995;122(7):481-6.
5. Guh DP, Zhang W, Bansback N, Amarsi Z, Birmingham CL, Anis AH. The incidence of co-morbidities related to obesity and overweight: a systematic review and meta-analysis. BMC Public Health. 2009;9:88.
6. Bhaskaran K, Douglas I, Forbes H, dos-Santos-Silva I, Leon DA, Smeeth L. Body-mass index and risk of 22 specific cancers: a population-based cohort study of 5.24 million UK adults. Lancet. 2014;384(9945):755-65.
7. Kyrgiou M, Kalliala I, Markozannes G, et al. Adiposity and cancer at major anatomical sites: umbrella review of the literature. BMJ. 2017;356:j477.
8. Afshin A, Forouzanfar MH, et al; GBD 2015 Obesity Collaborators. Health effects of overweight and obesity in 195 countries over 25 years. N Engl J Med. 2017;377(1):13-27.
9. Flegal K, Kit B, Orpana H, Graubard BI. Association of all-cause mortality with overweight and obesity using standard body mass index categories: a systematic review and meta-analysis. JAMA. 2013;309(1):71-82.
10. Borrell LN, Samuel L. Body mass index categories and mortality risk in US adults: the effect of overweight and obesity on advancing death. Am J Public Health. 2014;104(3):512-9.
11. Dobbins M, Decorby K, Choi BC. The association between obesity and cancer risk: a meta-analysis of observational studies from 1985 to 2011. ISRN Prev Med. 2013;2013:680536.
12. Whitlock G, Lewington S, Sherliker P, et al; Prospective Studies Collaboration. Body-mass index and cause-specific mortality in 900,000 adults: collaborative analyses of 57 prospective studies. Lancet. 2009;373(9669):1083-96.
13. U.S. Preventive Services Task Force. Screening for abnormal blood glucose and type 2 diabetes mellitus: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2015;163(11):861-868.
14. U.S. Preventive Services Task Force. Screening for high blood pressure in adults: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2015;163(10):778-86.
15. US Preventive Services Task Force. Statin use for the primary prevention of cardiovascular disease in adults: US Preventive Services Task Force recommendation statement. JAMA. 2016;316(19):1997-2007.
16. U.S. Preventive Services Task Force. Behavioral and pharmacotherapy interventions for tobacco smoking cessation in adults, including pregnant women: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2015;163(8):622-34.
17. U.S. Preventive Services Task Force. Aspirin use for the primary prevention of cardiovascular disease and colorectal cancer: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2016;164(12):836-45.
18. U.S. Preventive Services Task Force. Behavioral counseling to promote a healthful diet and physical activity for cardiovascular disease prevention in adults with cardiovascular risk factors: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2014;161(8):587-93.
19. US Preventive Services Task Force. Behavioral counseling to promote a healthful diet and physical activity for cardiovascular disease prevention in adults without cardiovascular risk factors: US Preventive Services Task Force recommendation statement. JAMA. 2017;318(2):167-74.
20. US Preventive Services Task Force. Screening for obesity in children and adolescents: US Preventive Services Task Force recommendation statement. JAMA. 2017;317(23):2417-2426.
21. Community Preventive Services Task Force (CPSTF). CPSTF findings for obesity. The Community Guide website. https://www.thecommunityguide.org/content/task-force-findings-obesity. Accessed July 31, 2018.
22. Ogden CL, Carroll MD, Kit BK, Flegal KM. Prevalence of childhood and adult obesity in the United States, 2011-2012. JAMA. 2014;311(8):806-14.
23. National Center for Health Statistics. Health, United States, 2016: With Chartbook on Long-term Trends in Health. Hyattsville, MD: National Center for Health Statistics; 2017. Report 2017-1232.
24. Flegal KM, Kruszon-Moran D, Carroll MD, Fryar CD, Ogden CL. Trends in obesity among adults in the United States, 2005 to 2014. JAMA. 2016;315(21):2284-91.
25. Echeverria SE, Mustafa M, Pentakota SR, et al. Social and clinically-relevant cardiovascular risk factors in Asian Americans adults: NHANES 2011-2014. Prev Med. 2017;99:222-7.
26. LeBlanc EL, Patnode CD, Webber EM, Redmond N, Rushkin M, O’Connor EA. Behavioral and pharmacotherapy weight loss interventions to prevent obesity-related morbidity and mortality in adults: evidence report and systematic review for the US Preventive Services Task Force. JAMA. 2018;320(11):1172-1191.
27. Knowler WC, Barrett-Connor E, Fowler SE, et al. Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl J Med. 2002;346(6):393-403.
28. Tuomilehto J, Lindström J, Eriksson JG, et al; Finnish Diabetes Prevention Study Group. Prevention of type 2 diabetes mellitus by changes in lifestyle among subjects with impaired glucose tolerance. N Engl J Med. 2001;344(18):1343-50.
29. Lindström J, Peltonen M, Eriksson JG, et al; Finnish Diabetes Prevention Study (DPS). Improved lifestyle and decreased diabetes risk over 13 years: long-term follow-up of the randomised Finnish Diabetes Prevention Study (DPS). Diabetologia. 2013;56(2):284-93.
30. Ochner CN, Barrios DM, Lee CD, Pi-Sunyer FX. Biological mechanisms that promote weight regain following weight loss in obese humans. Physiol Behav. 2013;120:106-113.
31. Rosenbaum M, Kissileff HR, Mayer LE, Hirsch J, Leibel RL. Energy intake in weight-reduced humans. Brain Res. 2010;1350:95-102.
32. National Institutes of Health. Clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults—the evidence report. Obes Res. 1998;6(suppl 2):51S-209S.
33. U.S. Preventive Services Task Force. Screening for and management of obesity in adults: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2012;157(5):373-378.
34. Brauer P, Connor Gorber S, Shaw E, et al; Canadian Task Force on Preventive Health Care. Recommendations for prevention of weight gain and use of behavioural and pharmacologic interventions to manage overweight and obesity in adults in primary care. CMAJ. 2015;187(3):184-195.
35. Jortberg B, Myers E, Gigliotti L, et al. Academy of Nutrition and Dietetics: standards of practice and standards of professional performance for registered dietitian nutritionists (competent, proficient, and expert) in adult weight management. J Acad Nutr Diet. 2015;115(4):609-18.e40.
36. Jensen MD, Ryan DH, Apovian CM, et al; American College of Cardiology/American Heart Association Task Force on Practice Guidelines; Obesity Society. 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and The Obesity Society. J Am Coll Cardiol. 2014;63(25 Pt B):2985-3023.
37. Garvey W, Garber A, Mechanick J, et al; The AACE Obesity Scientific Committee. American Association of Clinical Endocrinologists and American College of Endocrinology position statement on the 2014 advanced framework for a new diagnosis of obesity as a chronic disease. Endocr Pract. 2014;20(9):977-89.
38. Stegenga H, Haines A, Jones K, Wilding J; Guideline Development Group. Identification, assessment, and management of overweight and obesity: summary of updated NICE guidance. BMJ. 2014;349:g6608.
39. American Academy of Family Physicians (AAFP). Clinical Preventive Service Recommendation: obesity. https://www.aafp.org/patient-care/clinical-recommendations/all/obesity.html. Accessed July 31, 2018.

^a BMI calculated as weight in kilograms divided by the square of height in meters.
^b The USPSTF recommends screening for abnormal blood glucose levels as part of cardiovascular risk assessment in adults aged 40 to 70 years who are overweight or have obesity. Patients with certain risk factors (family history of diabetes, personal history of gestational diabetes or polycystic ovarian syndrome, or being a member of certain racial/ethnic groups [African American, American Indian or Alaskan Native, Asian American, Hispanic or Latino, or Native Hawaiian or Pacific Islander]) may also be at increased risk of diabetes at a younger age or at a lower BMI and should be considered for screening.¹³

Abbreviation: BMI=body mass index.