By Ellen Feldman, MD

Altru Health System, Grand Forks, ND

Dr. Feldman reports no financial relationships relevant to this field of study.

SYNOPSIS: The U.S. Preventive Services Task Force evaluated the risks and benefits of interventions for weight loss and weight loss maintenance to prevent complications from obesity. Panelists found a moderate net benefit from weight loss-intensive behavioral interventions.

SOURCE: US Preventive Services Task Force; Curry SJ, Krist AH, Owens DK, et al. Behavioral weight loss interventions to prevent obesity-related morbidity and mortality in adults: US Preventive Services Task Force Recommendation Statement. JAMA 2018;320:1163-1171.

Obesity is a serious and growing problem that affects more than one-third of U.S. adults. Health problems related to obesity are numerous. Obesity increases the risk and complications from disorders such as cardiovascular disease, endocrine problems, maladies of the musculoskeletal system, and specific carcinomas, and increases the risk for death.1,2

The U.S. Preventive Services Task Force (USPSTF) generates recommendations based on evaluation of evidence by a volunteer panel composed of experts in preventive medicine and primary care. Recommendations are based solely on peer-reviewed studies; neither cost nor accessibility is factored into the analysis. However, insurers often use these recommendations to determine coverage. Each recommendation receives a letter grade (A, B, C, D, or I) reflecting strength of evidence and any concerns about harm. The goal is to provide primary care providers and patients a platform for discussion regarding specific preventive measures.3

This article reflects the latest USPSTF recommendations regarding prevention of morbidity and mortality related to obesity in adults. The recommendation to offer or refer patients with a body mass index (BMI) of 30 kg/m2 for behavioral interventions received a “B” from the organization, meaning there is “moderate certainty” that the net benefit is moderate. The USPSTF categorizes BMI from 25 to 29.9 kg/m2 as overweight and BMI of 30 kg/m2 as obese. BMIs higher than this are subdivided further into obesity classes 1, 2, and 3.4

The USPSTF evaluated studies related to behavioral or pharmaceutical interventions for weight loss or weight loss maintenance. It reviewed 124 studies: 80 involved behavioral-based weight loss; nine concerned behavior-based weight loss maintenance; 32 were about pharmacotherapy for weight loss; and three involved pharmacotherapy for weight loss maintenance. No surgical or weight loss device studies or trials were considered, as these were believed to fall outside the scope of the review.

The behavioral interventions consisted of a multimodal approach incorporating diet, physical activity, and psychological interventions in most reviewed studies. Most studies were intensive and included at least 12 sessions during year 1. Interventions ranged from in-person counseling sessions to DVD learning to text messaging. Participation rates were high. The degree of heterogeneity precluded a recommendation regarding the most effective type of behavioral intervention. However, these methods showed evidence of efficacy, with a risk ratio at 12- to 18-month follow-up of 1.94 (95% confidence interval, 1.70-2.22) for participants losing or maintaining at least 5% of baseline weight compared with control subjects. In other words, the behavioral intervention was associated with almost two times the probability of weight loss or weight loss maintenance in follow-up.

Pharmacotherapy investigations included the following agents usually combined with behavioral interventions: liraglutide (four trials), lorcaserin (four trials), naltrexone/bupropion (four trials), orlistat (21 trials), and phentermine/topiramate (three trials). The USPSTF found the pharmacotherapy trials to be of fair quality, but was unable to complete a meta-analysis because of high variability in outcome measures in the context of the limited number of studies for each agent. Additionally, it noted that fairly stringent criteria for inclusion in these trials (typically, participants needed to demonstrate medication compliance and/or meet a weight loss goal for eligibility) impeded the ability to generalize results. Potential harms of these agents may have led to an observed higher dropout rate when compared to the group with behavioral interventions only. However, those who completed the combined interventions lost more weight over 12 to 18 months than the group with behavioral interventions alone.

Given concerns about generalizability of the pharmacology studies, the potential harms, and the difficulty performing a meta-analysis, the USPSTF recommendations focused on multimodal intensive behavioral interventions and made no recommendations regarding psychopharmacological interventions.

Recommendations to offer or refer all adults with BMI 30 kg/m2 to intensive, multicomponent behavioral interventions for weight loss or weight loss maintenance are clear. It is less clear how to convert the recommendations into a meaningful, clinically relevant process. In a November 2018 JAMA editorial, Haire-Joshu and Hill-Briggs noted barriers and challenges to making the recommendations reality. These include underdiagnosis of obesity in primary care, a decrease in weight management counseling over the last decade, and many higher-risk patients (young adults and those with lower socioeconomic status) who are less likely to see a primary care provider. Haire-Joshu and Hill-Briggs discussed the benefits of recruiting and training lay-persons to reach deep into communities rather than waiting for members of high-risk populations to come to primary care. They also discussed the advantages of training lifestyle or health coaches for this work.5

Although the USPSTF recommendations for intensive multimodal behavioral interventions were not specific, they do give rise to a few guidelines for patients. Most interventions included at least 12 sessions the first year. Most incorporated support for dietary modification along with physical activity. Primary care and integrative medicine providers remain at the forefront in screening, diagnosing, and referring patients with obesity. However, not all persons who are interested in weight loss seek medical care. Collaborating with well-trained community members to extend preventive efforts into areas traditionally not associated with medicine, such as community centers, schools, and religious organizations, potentially can help providers reach this segment of the population. Public speaking and efforts at forming nutritionally sound public policy measures also can be effective ways to extend this message. These steps out of the office can help USPSTF recommendations become a reality for individuals who may not yet be part of a primary care practice.

REFERENCES

  1. West Virginia Health Statistic Center. Obesity: Facts, Figures, Guidelines. Available at: https://bit.ly/1REDU0U. Accessed March 25, 2019.
  2. World Health Organization. Obesity and overweight. Available at: https://bit.ly/2Lul9Q9. Accessed March 25, 2019.
  3. U.S. Preventive Services Task Force. Available at: https://bit.ly/2jyrhLQ. Accessed March 25, 2019.
  4. Yao A. Screening for and management of obesity in adults: U.S. Preventive Services Task Force recommendation statement: A policy review. Ann Med Surg (Lond) 2012;2:18-21.
  5. Haire-Joshu D, Hill-Briggs F. Treating obesity — Moving from recommendation to implementation. JAMA Intern Med 2018;178:1447-1449.