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Is Weight Loss All In Your Head? New Research Examines Behavioral, Psychological Factors

A woman in a black shirt exercises while smiling and holding an apple
Written By Nick Wilson

A comprehensive weight-loss maintenance study led by a Cal Poly research team and supported by WeightWatchers found that a wide range of factors — from body image, to food cues that spark cravings, to self-monitoring — can differ between people who regain weight versus those who do not. 

“This study comprehensively examines the different factors that relate to weight loss maintenance versus regain among those who had already lost over 20 pounds,” said Suzanne Phelan, director of Cal Poly’s Center for Health Research and a professor of kinesiology and public health in the Bailey College of Science and Mathematics. “And because the study is so comprehensive, we have the ability to determine which factors are most important.” 

A woman in a black polo shirt smiles into the camera.
Professor Suzanne Phelan.

The study assessed 2,843 individuals, all participants who had lost at least 20 pounds and kept it off for at least one year on the WeightWatchers weight-management program. On average, they had lost 56 pounds and kept it off for three and a half years. One year later, 57.4% were classified as “weight maintainers” (having maintained their weight within roughly five pounds) and 42.6% as “gainers” (those who gained at least five pounds).

“Relative to those who maintained weight loss, those who gained at least five pounds showed greater challenges in sustaining eating habits in the face of a variety of food cues or triggers such as the sight of food, social situations, taste and smell of food, and feelings,” said Gary Foster, chief scientific officer at WeightWatchers. “Similarly, those who maintained weight loss had greater acceptance of uncomfortable food cravings and showed greater intrinsic drives to consume less healthy foods that conflicted with weight loss goals.”

Bodily pain, caused by factors such as injuries or health problems, was another contributor to weight gain and considered a “quality-of-life metric.”

“We’re unsure if bodily pain caused overeating and reduced activity or if weight regain preceded bodily pain,” said Phelan, emphasizing the need for more frequent follow-up. “The team will conduct annual assessments and develop interventions for overeating, body image and self-monitoring. Promoting positive body image, irrespective of size, is crucial, as it's linked to better psychological and physical well-being, including addressing weight regain.” 

“This new study is hugely encouraging," said Foster. "It reaffirms our belief that there isn't only one way to support an individual's weight health, and in fact, there are many complex factors that determine positive outcomes.

“By acknowledging and understanding these nuances whether that is the critical need for self-compassion, or the importance of monitoring, we can help people to access the right tools for them in the long term,” he said.

Phelan was invited to present the group's findings at the prestigious Obesity Journal Symposium on Oct. 16 in Dallas. Her presentation will took place during the 41st annual meeting of The Obesity Society, a nonprofit and leading organization of about 2,800 scientists and health professionals devoted to understanding and reversing the epidemic of obesity and its adverse health.

Insights and findings from the study were also published in the Oct. 16 edition of Obesity, a peer-reviewed journal covering topics regarding health and medicine.

Phelan, along with colleagues at the University of Florida College of Medicine and the Perelman School of Medicine at the University of Pennsylvania, will continue the study on an annual basis and will also compare U.S. weight-loss maintainers with people from around the world.