Obese patients who receive regular sessions of intensive behavioral therapy (IBT), which provides diet and physical activity counseling, can achieve meaningful weight loss in six to 12 months, according to a new Penn Medicine study published in the journal Obesity.
The study is the first randomized controlled evaluation of the efficacy of IBT when implemented under the Centers for Medicare and Medicaid Services (CMS) coverage guidelines.
“Intensive behavioral counseling is a proven method for helping people modify their eating and physical activity habits and achieve significant weight loss,” said study leader Tom Wadden, Ph.D., a psychology professor at Perelman School of Medicine at the University of Pennsylvania.
“We hope the findings from our study will encourage broader use of behavioral weight loss counseling under the CMS benefit and in other primary care settings.”
Wadden conducted the study with Jena Tronieri, Ph.D., an assistant professor of psychology, and found that patients who received IBT lost an average of 6.1 percent of their initial body weight at one year.
Medicare beneficiaries with obesity are eligible to receive IBT from a qualified health professional in a primary care setting. CMS covers weekly counseling visits for the first month, and then sessions every other week for the next five months. Patients who lose 6.6 pounds (3 kilograms) or more are eligible for six additional monthly sessions. Most private health insurers offer more limited coverage — if any at all — of IBT for obesity.
In the study, 150 obese participants were randomly assigned to one of three treatment groups, all of which provided distinct, one-year intervention regimens. Participants in each group were given 21 individual IBT counseling sessions as provided under the CMS coverage guidelines.
In group one, participants received IBT alone. This involved counseling from a physician, nurse practitioner or registered dietitian, and instructions to consume a diet of 1,200 to 1,800 calories a day (based on their body weight) and to gradually increase their physical activity to 225 minutes per week.
In addition to the IBT, participants in the second group received the medication liraglutide (3.0 mg), a drug approved by the U.S. Food and Drug Administration for chronic weight management.
Participants in the third group received the IBT counseling, liraglutide, and a prescription for 12 weeks of daily meal replacements.
The results show that 44 percent of those who received IBT alone lost 5 percent or more of baseline body weight, a measure of clinically meaningful weight loss.
More than 70 percent of the participants in both the second and third groups lost 5 percent or more of their baseline body weight, with an average loss of 11.5 percent and 11.8 percent of baseline weight, respectively. The significant weight loss experienced by participants who received liraglutide, in addition to IBT, is consistent with previous studies of existing weight loss medications.
All three interventions also were associated with improvements in average systolic and diastolic blood pressure, waist circumference, triglycerides, symptoms of depression and other cardiovascular risk factors.
Liraglutide appears to trigger weight loss, in part, by decreasing hunger and increasing the feeling of fullness after eating, according to additional data recently presented by Tronieri at Obesity Week, an international conference held in Nashville, Tennessee.
Tronieri observed a subset of patients within the larger trial and found that those who received IBT-liraglutide, compared with IBT-alone, reported significantly greater reductions in hunger and preoccupation with food during the first 24 weeks.
Tronieri’s study found no significant differences between the two groups in reported appetite control at weeks 40 or 52, though IBT-liraglutide participants still maintained nearly double the weight loss.
The IBT study also revealed that participants treated by a physician or nurse practitioner lost comparable amounts of weight to those treated by a registered dietitian, showing the practicality of educating primary care practitioners to provide this kind of therapy.
“We encourage CMS to expand the scope of practitioners who are eligible to provide IBT independently, which is currently limited to physicians, nurse practitioners, physician assistants and nurse specialists,” Tronieri said.
The research team believes the findings need to be replicated in a larger sample of participants who are treated in primary care practices, rather than in a specialized weight management clinic.
“As we move forward, we need to assess the effectiveness and cost of providing IBT in person, versus delivering it via a digital platform — like a mobile app or online patient portal,” Wadden said. “Millions of Americans could benefit from IBT, and we need to find low-cost, effective ways of getting it to them.”