I guess I need to address an article in this week’s New England Journal of Medicine that demonstrates how exercise can prevent the relapse of weight gain after accomplishing weight loss by eating less calories. (1) For losing weight, exercise has finally been dismissed as being useful. But a lot of people are still saying that to maintain weight loss after you lose by dieting exercise is helpful, despite evidence that it has minor effect or no effect. This report of a study from Denmark would give support to this maintenance part of benefit for exercise in the treatment of obesity.
These investigators started with 215 obese participants of whom 195 accomplished a weight loss of at least 5% by eating a low-calorie diet for 8 weeks. The average weight loss of those eligible persons was 29 pounds or a 12% reduction in body weight. They then divided these into 4 groups for an observation of weight loss maintenance for another 52 weeks. One group got the exercise program and placebo, the second group got liraglutide alone, the third group got a combination of both and a fourth group was placebo. Eighty-five percent, 166 participants, finished the experiment.
The placebo group put half of the weight lost back on. The exercise alone group only put 7% of the weight lost back on. The liraglutide group maintained all of the weight lost and the combo group actually lost 7 and a half pounds more over the 52 weeks. So the weight loss maintenance benefit of liraglutide was slightly better than exercise alone and the combination was additive. In the case of fat tissue loss the benefits were even more pronounced in the same directions.
Why was exercise beneficial for weight loss maintenance here in contradiction of prior evidence. Are Danish people different? One part of the answer might be that the exercise program was predominantly of vigorous intensity and they had a high compliance and supervision of about two hours per week. Maybe the Danish are different.
A few more pieces of background about exercise bears repeating. There are 2 kinds of exercise termed body building and aerobic. There is a real thing, variously defined, called fitness that comes from exercising hard and consistently over time. When you get fit your efficiency during exercise and between bouts of exercise for the motions of daily living goes up. That means the energy cost, calories burned, goes down during and between exercise spells. Your heart rate and blood pressure go down and lots of other good things happen. So since even though you burn more calories while you are exercising hard, overall and in the course of the rest of your daily activity the calories you’re using go down and you eat less. All of this is unrelated to your size and shape per se.
Bottom line if you can be as dedicated and disciplined as the Danes forever then exercise maybe can help you maintain some weight loss after all and even though GLP-1s like liraglutide are easier if you exercise you can even improve on that weight lost. The GLP-1s and possible interactions with exercise are an even bigger story for later.
1. Lundgren JR et al. Healthy weight loss maintenance with exercise, liraglutide or both combined. N Engl J Med 2021;384:1719-30.
This writer’s opinion is their own and not the opinion of this newspaper
John DiTraglia M.D. is a Pediatrician in Portsmouth. He can be reached by e-mail- firstname.lastname@example.org or phone-354-6605.