Topic Spotlight


As of March 2020, the U.S. adult obesity prevalence was nearly 42%. (Centers for Disease Control and Prevention)

1 in 5

About one in five children and adolescents in the United States have obesity. (Centers for Disease Control and Prevention)


PCORI supports 21 comparative clinical effectiveness research studies related to obesity. (As of February 2022)

Evidence for Decisions from PCORI-Funded Studies

Evidence Updates: Comparing Two Types of Weight Loss Surgery

Bariatric surgery can help people with obesity lose weight and improve problems related to obesity, like diabetes. But surgery can also cause harm, and outcomes may vary across different procedures. A PCORI-funded study compared the benefits and harms of the two most common types of bariatric surgery: Roux-en-Y gastric bypass, or gastric bypass, and sleeve gastrectomy, or sleeve surgery.

A pair of Evidence Updates is now available that can help clinicians and patients work together to make informed decisions regarding patient care.

View the Evidence Updates

Study Results that Support Better-Informed Decisions

Comparing Ways to Treat People with Obesity in Rural United States

People living in rural areas are more likely to have obesity than those living in cities, and they are also less likely to have access to weight loss programs. This PCORI-funded study compared three ways to treat obesity in rural populations: regular in-person clinic sessions, in-person group sessions, and phone-based group sessions.

In a paper published January 2021 in JAMA, the study reported that people in the in-person group sessions averaged greater weight loss after 24 months than the other two groups.

Comparative Effectiveness of Different Approaches to Weight Loss Management Programs

This PCORI-funded study compared three types of weight loss management programs for people with high blood pressure or type 2 diabetes who also had overweight or obesity. The study compared outcomes of patients in three groups: an online weight management program with meal plans, menus, and a weight tracker; that same program plus support from a health manager; and usual care.

As reported in JAMA, the group that used the online weight management program and had access to a health manager, on average, experienced a statistically significant greater weight loss after 12 months compared to the other two groups.

Key Lifestyle Changes Can Help Patients with Obesity Lose More Weight, Keep It Off Longer, Study Finds

Reporting in the New England Journal of Medicine, the PROPEL Study found that an intensive healthy lifestyle intervention—which included health coaches embedded in primary care practices working with patients to develop healthy habits—resulted in patients losing significantly more weight than those who received usual care from their primary care clinics, and they kept more weight off at two years later.

The results show that successful weight loss can be achieved in primary care settings in a highly underserved population who have significant barriers to obtaining health care services.

Five-Year Outcomes for Common Bariatric Surgeries

The PCORnet® Bariatric Study—which is using data from PCORnet, The National Patient-Centered Clinical Research Network—to study outcomes among patients who undergo common weight-loss surgeries has published several papers in prominent medical journals. The most recent clinical findings, published in JAMA Surgery, are on diabetes remission outcomes among patients who underwent gastric bypass and gastric sleeve surgeries.

Another article, also published in JAMA Surgery, details the five-year outcomes of patients who underwent either gastric bypass or adjustable banding, finding that gastric bypass patients were significantly more likely than gastric sleeve patients to end up back in the hospital in the years following surgery.

Obesity Study Spotlights

PCORnet® Improves Decision Making for Patients with Obesity

PCORI-funded study Principal Investigator David Arterburn, MD, MPH. discusses the focus of The PCORnet® Bariatric Study and the advantages of using PCORnet®, The National Patient-Centered Clinical Research Network, to conduct research.