The argument surrounding diet versus exercise for weight loss seems as old as the chicken and egg theory.We all recognize that chronic dieting is difficult and not the best for our psyche in the long term. Now, a new study shines some light on the question of why dieters have difficulty maintaining their weight loss over time. The March issue of Obesity published the study by Danielle Ostendorf, Ph.D., a postdoctoral fellow at the CU Anschutz Health and Wellness Center which shows that participating in high levels of exercise helped prevent weight regain in a group of weight-loss maintainers (1).Rather than be in a state of chronic calorie restriction, the study indicates that those who were successful at keeping weight off relied on physical activity to prevent weight regain. Participants in the study lost at least 30 lbs. and maintained the loss for over a year (1).The research compared successful weight-loss maintainers to two groups- normal weight controls with BMIs similar to the weight-loss maintainers and overweight/obese subjects whose present BMIs were close to the pre-weight-loss BMI of the maintainers. The bodyweight of the weight-loss maintainers was ~150 lbs. which was nearly the same as the normal-weight controls and controls who were overweight or obese had a bodyweight of roughly 213 lbs (1).Some key points to the study include:

• Weight loss maintainers worked off (and ate) roughly 300 more calories per day than the people at normal weight controls, but what they ate was not statistically different from what overweight/obese individuals ate.
• The number of calories burned by weight loss maintainers through physical activity was higher (180 kcal/day) compared to normal-weight individuals and overweight/obese individuals, which provides evidence that the weight loss maintainers move more.
• Weight loss maintainers also reported higher step levels (12,000 steps daily) compared with people at normal body weight (9,000 steps per day) and overweight/obese individuals (6500 steps daily) (1).

According to Dr. Victoria A. Atenacci, a weight management doctor and researcher at CU Anschutz Medical Campus, "Our findings suggest that this group of successful weight-loss maintainers is 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" (1).This is one of only a few studies to calculate total daily energy use in individuals who have lost weight using the doubly labeled water method, which is the gold standard. This procedure lets researchers more accurately explore an individual’s energy expense through urine sample collection over one to two weeks after consumption of doubly labeled water. Doubly labeled water has both hydrogen and oxygen atoms replaced (labeled) with an uncommon isotope of each element to be used for tracing purposes (1).An estimate of calorie intake while people are weight stable is calculated using a measurement of total daily energy expenditure from doubly labeled water. Previous research relied on questionnaires or food diaries to measure energy intake, which have obvious limitations.The resting metabolic rate (RMR) of each participant was also measured. The RMR provides information on how much of the total daily energy expenditure is energy spent at rest versus energy used during physical activity. Techniques such as self-reported measures of activity monitors to measure physical activity were used in the past and do not provide the same accuracy (1).The results of this study are in line with the conclusions from the longitudinal study of “The Biggest Loser” contestants which showed that after six years, physical activity expenditure was strongly correlated with weight loss (2).If your clients are struggling with weight regain, they still need to be mindful of limiting calorie-dense food and liquids such as fried foods, high-calorie desserts, soft drinks, and alcohol. However, they should not have to remain on a stringent diet forever. Encourage more fruits and vegetables. Suggest whole grains over processed grains. Advise lean and plant-based proteins. But especially encourage more movement. Have them try a new exercise class or join a walking group at work. Suggest they use stretchy bands or free weights while watching TV. In addition to weight control, exercise helps reduce depression, improve bone density and prevent diabetes, heart disease, and cancer (3).By Lisa Andrews, MEd, RD, LDReferences:

1. Ann E. Caldwell, Seth A. Creasy Zhaoxing Pan Kate Lyden Audrey Bergouignan Paul S. MacLean, Holly R. Wyatt James O. Hill Edward L. Melanson Victoria A. Catenacci. Physical Activity Energy Expenditure and Total Daily Energy Expenditure in Successful Weight Loss Maintainers. Obesity, Volume27, Issue3, March 2019. Pages 496-504
2. https://www.scientificamerican.com/article/6-years-after-the-biggest-loser-metabolism-is-slower-and-weight-is-back-up/
3. Frank W. Booth, Ph.D.,1 Christian K. Roberts, Ph.D.,2 and Matthew J. Laye, Ph.D.3 Lack of exercise is a major cause of chronic diseases. Compr Physiol. 2012 Apr; 2(2): 1143–1211.