Regular physical activity is more effective than a restricted diet for maintaining weight loss, according to a new study from the University of Colorado Anschutz Health and Wellness Center (AHWC) at the CU Anschutz Medical Campus.
The findings are published as an Editor’s Choice article in the journal Obesity.
“This study addresses the difficult question of why so many people struggle to keep weight off over a long period,” said Danielle Ostendorf, Ph.D., a postdoctoral fellow at the CU Anschutz Health and Wellness Center.
“By providing evidence that a group of successful weight-loss maintainers engages in high levels of physical activity to prevent weight regain — rather than chronically restricting their energy intake — is a step forward to clarifying the relationship between exercise and weight-loss maintenance.”
In the study, successful weight-loss maintainers were those who maintained a reduced body weight of 30 pounds or more for over a year.
Overall, the findings show that successful weight-loss maintainers are more likely to depend on physical activity to remain in energy balance (rather than chronic restriction of dietary intake) to avoid gaining their weight back.
The research team looked at successful weight-loss maintainers compared to two other groups: controls with normal body weight — body mass index (BMI) similar to the current BMI of the weight-loss maintainers — and controls with overweight/obesity (whose current BMI was similar to the pre-weight-loss BMI of the maintainers).
The weight-loss maintainers had a body weight of around 150 pounds, which was similar to the normal weight controls, while the controls with overweight and obesity had a body weight of around 213 pounds.
Key findings include:
- The total calories burned (and consumed) each day by weight-loss maintainers was much higher (300 kcal/day) compared with that in participants with normal body weight but was not significantly different from that in overweight/obese participants;
- Notably, of the total calories burned, the amount burned in physical activity by weight-loss maintainers was significantly higher (180 kcal/day) compared with that in both individuals of normal body weight and those with overweight/obesity. Despite the higher energy cost of moving a larger body mass in those with overweight/obesity, weight-loss maintainers were burning more energy in physical activity, suggesting they were moving more;
- This is supported by the fact that the weight-loss maintainer group also demonstrated significantly higher levels of steps per day (12,000 steps per day) compared to participants at a normal body weight (9,000 steps per day) and participants with overweight/obesity (6,500 steps per day).
“Our findings suggest that this group of successful weight-loss maintainers are consuming a similar number of calories per day as individuals with overweight and obesity but appear to avoid weight regain by compensating for this with high levels of physical activity,” said Victoria A. Catenacci, M.D., a weight management physician and researcher at CU Anschutz Medical Campus.
The results are consistent with those from the longitudinal study of “The Biggest Loser” contestants, where physical activity energy expenditure was significantly linked to weight loss and weight gain after six years.