Drexel Joins NIH Study to Understand Why Dieters Regain Weight

For almost two decades weight loss research has shown that some — but not all — people regain weight they have lost after making dietary changes or increasing physical activity. Researchers from Drexel University are helping to lead a $3.7 million National Institutes of Health effort to understand why this is the case as recent developments in weight loss interventions are raising new questions about how we understand this public health challenge.

Because relatively little is known about how changes in specific components of metabolism and appetite contribute to weight regain, researchers Michael Lowe, PhD, of Drexel University, Kelly Allison, PhD and Matthew Hayes, PhD, of the Perelman School of Medicine at the University of Pennsylvania, and Susan Roberts, PhD, of Tufts University, have answered the NIH’s call to investigate.

The team will attempt to answer the age-old question: What is the secret sauce of preventing substantial weight regain?

Previous research has suggested the possibility of a weight “set point” — with factors such as increased appetite and reduced activity encouraging the body to return to the original weight. However, people regain weight to different degrees and scientists want to know why some people are able to maintain a reduced weight while others struggle with weight regain. 

Lowe and his colleagues are aiming to determine how diet-induced weight loss affects psychological, metabolic and neurological measures, including food intake and appetite drive, metabolic rate and physical activity. They will evaluate these changes to determine if they can be used as predictors of future weight regain, with the hope that better understanding of the specific causes of weight regain can improve the durability of current weight loss treatments.

“Current research and societal beliefs have some dieters believing it’s a futile exercise,” said Lowe, a professor in Drexel’s College of Arts and Sciences. “By conducting this research, we hope to explain why some people regain weight and that dieting is not self-defeating when effective approaches to weight maintenance are taken.”

The comprehensive and rigorous clinical trial will begin this month. The team will study participants over an 18-month long trial period — from the weight loss phase through maintenance phase. They will collect physical, biological and psychological measurements at each stage of the trial: assessment of the multiple ways the body uses energy; body composition; how the brain responds to food cues; hormonal and metabolic markers during test meals; and a measure of the time it takes food to empty out of the stomach during weight loss and regain.

The treatment program for weight loss and maintenance will be modeled after the National Diabetes Prevention Program, which was designed to help people lose 7% or more of their body weight through healthier eating and physical activity.

Each phase – beginning of trial, behavioral weight loss period, and four-month and 12-month follow ups – will allow for maintenance to be studied as a process, not just as a sudden shift. According to the research team, the data will be used to predict weight regain at 12 months.

“This study is unique because of the comprehensive and rigorous measures we’re taking,” said Allison, director of the Center for Weight and Eating Disorders at Penn Medicine. “We’re chasing down every possible influence on weight regain, from behavior down to the cellular and molecular level.” 

For more information on the study and trial participation, visit: powers-study.org.