Cal Poly Study Finds Weight-Loss Maintainers Sit Less Than Weight-Stable People with Obesity

SAN LUIS OBISPO — A new Cal Poly study found that people who lost weight and kept it off spent less time sitting compared to people with obesity whose weight stayed the same. This is the first study to examine time spent in various sitting activities among weight-loss maintainers. The research was published today in the journal Obesity.

In 2006, the National Weight Control Registry showed that weight-loss maintainers watched significantly less television than controls, but other sitting activities weren’t included in the registry. The Rhode Island-based research study includes more than 10,000 who have lost at least 30 pounds of weight and kept it off for at least one year.

In the Cal Poly study, weight-loss maintainers and controls reported similar TV time, but weight-loss maintainers spent less time using a computer or video game outside of work.

Differences between the findings could reflect changes in electronic devices over the past 15 years, including the rise in availability of computers and video games.

Weight-loss maintainers and controls also spent about the same amount of time sitting while engaged in more mentally active forms of sedentary behavior, such as reading, studying, traveling, talking, texting and socializing.

“The findings hopefully will prompt future weight maintenance intervention research testing the effects of and optimal approaches for reducing sedentary behavior, including non-work-related computer and video game usage.,” said Suzanne Phelan one of the study’s lead authors, director of Cal Poly’s Center for Health Research, and a professor in the Kinesiology and Public Health Department. “Future research should include objective measures of sedentary behavior and activity.”

Participants in the study included 4,305 weight-loss maintainers from WW (formerly Weight Watchers) who had maintained a weight loss of more than 20 pounds for an average of more than three years and had an average current body mass index (BMI) of 27.6 kg/m2. The group of weight-stable individuals with obesity had an average BMI of 38.9 kg/m2.

The BMI calculation divides an adult’s weight in kilograms by their height in meters squared. For most adults, an ideal BMI is in the 18.5 to 24.9 range. People with a BMI that ranges between 25 and 29.9 are considered overweight; those between 30 and 39.9 have obesity.

One of the key findings relates to time spent seated.

Weight-loss maintainers spent three fewer hours per day sitting than weight-stable individuals with obesity. Compared with controls, weight-loss maintainers spent one hour less per day in non-work-related sitting using a computer or playing a video game.

There were no meaningful differences between weight-loss maintainers and weight-stable individuals with obesity in the number of television sets and sedentary-promoting devices in the home. Weight-loss maintainers expended significantly more calories per week in physical activity, 1,835 versus 785.

A person weighing 250 pounds walking a normal pace of 3 mph for 60 minutes would burn nearly 420 calories — and walking five times a week would burn almost 2,100 calories.

“These findings are important for understanding behaviors that may enhance weight loss maintenance, and one of those may be to reduce sitting time and other modes of sedentary behavior,” said John M. Jakicic, distinguished professor, the highest honor accorded a faculty member at the University of Pittsburgh in Pennsylvania, and director of the Healthy Lifestyle Institute and the Physical Activity and Weight Management Research Center.

“However,” added Jakicic (who was not associated with the research), “this study also showed that physical activity was associated with improved weight loss maintenance. Thus, this study does not imply that simply standing more rather than sitting will contribute to weight loss maintenance but may suggest that less sitting that results in more movement is what is key to weight loss maintenance.

“Hence, sit less and move more.”

Researchers from Texas A&M and WW also contributed to the study. This research was supported by a grant from WW International, Inc.

To see the paper, visit

May 24, 2021
Contact: Suzanne Phelan


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