Weight loss is 80 per cent diet and 20 per cent exercise, right? Well, that’s where we’re wrong. According to a world first study published in the journal Obesity, abs aren’t made in the kitchen, and in actual fact, physical activity actually does more to maintain substantial weight loss than diet.
Researchers from the University of Colorado Anschutz Health and Wellness Center (AHWC) at the CU Anschutz Medical Campus revealed that successful weight-loss maintainers – those who are able to maintain a reduced body weight of 30 pounds (13.6kg) or more for over a pear – rely on physical activity to remain in energy balance to avoid weight gain, compared to restriction of dietary intake.
“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.”
To conduct the study, the researchers compared weight-loss maintainers to two other groups: controls with individuals of normal body weight (BMI similar to the current BMI of the weight-loss maintainers); and controls with overweight or obese individuals (those with a BMI similar to the pre-weight-loss BMI of the maintainers). The weight-loss maintainers had a body weight of approximately 68kg, while the controls who were overweight had a body weight of approximately 97kg.
The researchers precisely determined an individual’s energy expenditure and intake by collecting their urine samples over one to two weeks after given a dose of doubly labelled water – a water in which both the hydrogen and oxygen atoms are replaced with an uncommon isotope of these elements for tracing purposes.
The researchers also measured each individual’s resting metabolic rate in order to understand how much of the total daily energy expenditure came from energy expended at rest versus energy expended from physical activity.
The team concluded the study with three findings:
1. The total calories consumed and burned each day by weight-loss maintainers was approximately 300 calories more compared to individuals with normal body weight controls, but was not significantly different from the overweight individuals.
2. The amount burned during physical activity by weight-loss maintainers was significantly higher (180 calories) compared to the two other control groups. Despite the high energy cost of moving a larger body mass for the overweight individuals, the weight-loss maintainers were burning more energy in physical activity.
3. The weight-loss maintainers 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 the overweight participants (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, MD, a weight management physician and researcher at CU Anschutz Medical Campus.