Being very physically active rather than restricting calories appears to be key to keeping the pounds from creeping back after successful weight loss, according to a small case-control study published in the March issue of Obesity. Researchers examined energy expenditure of 25 middle-aged people who, on average, had lost 26 kg (58 pounds) and kept it off for 9 years, and compared them with similar people who had normal or excess weight. "Strikingly," the individuals who successfully maintained this substantial long-term weight loss consumed roughly as many calories as those who were overweight/obese (and more than those who were normal weight). However, the people who kept the excess weight off were much more physically active. On average, they took 12,107 steps/day, much more than the 8935 steps/day in the normal-weight group and the 6477 steps/day in the overweight/obese group. This high level of physical activity corresponds to about 60 to 90 minutes/day of moderate-intensity physical activity (eg, walking) or 30 to 45 minutes/day of vigorous-intensity activity (eg, running). "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," lead author Danielle Ostendorf, PhD, a postdoctoral fellow at the University of Colorado Anschutz Medical Campus, said in a statement from the university. And in an accompanying commentary, Timothy S. Church, MD, MPH, PhD, and Corby K. Martin, PhD, from Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, note that this "physical activity dose associated with weight loss maintenance is large and daunting." "In addition and critically," they stress, "the Ostendorf results are striking in that the weight loss maintainers did not appear to maintain their weight loss via continuous calorie restriction. "Rather, the weight loss maintainers ate approximately the same number of calories per day as the control participants with overweight/obesity but had much higher energy burn from exercise." They wonder what drives these people to keep up this intense exercise and where do they find the time? Are these individuals the ones who derive more of the benefits from exercise — lower stress and anxiety, and better quality of life — and do they have a more supportive family or workplace, or better access to facilities to maintain a high level of exercise? "This highlights the need for further research to identify the physiological, psychological, and environmental factors that help people successfully maintain weight loss through large amounts of exercise, as such research will help shape future weight loss maintenance strategies," Church and Martin conclude. Is It Moving More or Eating Less? Ostendorf and colleagues aimed to examine the relative contributions of metabolism, physical activity, and caloric intake in long-term weight loss maintenance. From 2009 to 2012 they enrolled 80 adults with a mean age of 47 years at their center and stratified them into three groups: Successful weight-loss maintenance group, n = 25 (maintained weight loss ≥ 13.6 kg for ≥ 1 year) Normal-weight control group, n = 27 Overweight/obese control group, n = 28 The study excluded people with diabetes or cardiovascular disease and those who had undergone bariatric surgery, among other things. On average, people in the weight-loss maintenance group weighed 67.8 kg (149 pounds) and had a body mass index (BMI) of 24.1 kg/m2, which was similar to the normal-weight group. Those in the overweight/obese group weighed 96.7 kg (213 pounds) and had a BMI of 34.3 kg/m2. Participants were given a doubly labeled water test, which involved ingesting 2H and 18O isotopes and collecting urine samples over 7 days to determine their total daily energy expenditure. Indirect calorimetry was used to determine participants' resting energy expenditure. Physical activity energy expenditure was then calculated using both measures. Participants wore an activPAL (PAL Technologies) tracker 24 hours/day for 7 days. Those who maintained weight loss had a significantly higher physical activity energy expenditure (812 kcal/day) than those in the normal-weight group (621 kcal/day) or overweight/obese group (637 kcal/day). Total daily energy expenditure was also significantly higher in those who maintained weight loss (2495 kcal/day) than normal-weight controls (2195 kcal/day) but was similar to that in the overweight/obese controls (2573 kcal/day). Ostendorf and colleagues acknowledge this was a relatively small cross-sectional study and those who maintained weight loss were white and mainly women (80%), so "results may not be generalizable to other populations" and further study is needed. Nevertheless, they write, "results from this study provide valuable insight into how individuals successfully achieve long-term weight loss maintenance." These findings are also consistent with results from the longitudinal study of the Biggest Loser contestants, which found physical activity was strongly correlated with weight loss/weight regain at 6 years. The study was supported by grants from the National Institutes of Health and American Heart Association. Ostendorf and the editorialists have reported no relevant financial disclosures. Disclosures for the other authors are listed with the article. Source
