Exercise beats diet when it comes to weight loss

Research suggests it’s easier to keep weight off through exercise than nutrition.

Research out of the University of Colorado Anschutz Health and Wellness Center (AHWC) has found that exercise is more important to maintaining weight loss than diet.

These findings suggest that the key to losing weight and keeping it off is physical activity rather than restrictive eating.

“This study addresses the difficult question of why so many people struggle to keep weight off over a long period,” said Danielle Ostendorf, PhD, 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.”

The study

The study compared successful weight-loss maintainers with two control groups: one with normal body weight (similar to current BMI of study group), and another with an overweight or obese group (similar to pre-weight loss BMI of study group).

Researchers measured total daily energy expenditure using the ‘doubly labelled water method’. This involves collecting urine samples after participants have consumed ‘doubled labelled water’, which is water in which the hydrogen and oxygen atoms have been replaced with an uncommon isotope in order to trace them.

Results showed that the weight-loss maintainer group burned significantly more calories per day compared with both control groups. This group also performed significantly more exercise (measured in steps per day) than control groups.

The study did not appear to address whether the weight loss maintainer group benefited from excess post-exercise oxygen consumption (aka the afterburn effect) or from the metabolic effects of building muscle mass.

In the study’s conclusion, the researchers note that those who have been able to maintain their weight loss relied on physical activity to “remain in energy balance (and avoid weight regain) at a reduced body weight”.

“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, MD, a weight management physician and researcher at CU Anschutz Medical Campus.

This study has been published in the journal Obesity.


Ostendorf, DM et al. (2019.) ‘Physical Activity Energy Expenditure and Total Daily Energy Expenditure in Successful Weight Loss Maintainers.’
Obesity. Vol. 27: Issue 3. March 2019. First published: 25 February 2019.

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