While many people are able to lose weight with lifestyle changes, the toughest part is to keep that weight off. In fact, less than 10% of people who have lost 5% of their weight are able to keep it off long term. This is because our bodies are built by evolution to defend our body weight. When weight goes down, our hunger hormone (ghrelin) goes up, our fullness (satiety) hormones go down, and our metabolism slows down as well – all of which powerfully drive weight regain.
Many of my patients will describe a ‘yo-yo’ pattern over the years – they will be able to improve their weight for a while, but the weight then cycles back up again.
SO: what can we do to maintain weight after the hard work of losing weight with lifestyle changes?
Exercise without a dietary prescription hasn’t been much studied for weight maintenance, so a recent study took the interesting approach of pitting exercise vs weight management medication vs the two strategies combined, to see what would work to help maintain weight lost by dietary changes.
The study, published in the New England Journal of Medicine, enrolled 215 adults with obesity, without diabetes (BMI between 32-43, 64% women, average age 43 years), and helped them to lose weight over 8 weeks with a medically supervised low calorie meal replacement diet for 8 weeks. Those who were able to lose at least 5% of their weight (195 participants) with this diet were then randomized to one of four strategies, to see if weight loss could be maintained:
- exercise program: minimum 150 minutes per week of moderate-intensity aerobic physical activity, or 75 minutes of vigorous, or an equivalent combination, with an exercise instructor’s support, and the option of supervised group sessions
- weight management medication (liraglutide 3.0mg per day, trade name Saxenda)
- exercise program with liraglutide 3.0 mg
- placebo (no treatment)
All groups who were not taking liraglutide were taking a placebo medication instead, and both participants and study investigators were blinded (meaning neither knew who was on liraglutide or who was on placebo).
After the 8 week low calorie diet, the average weight loss was 13.1kg (12% weight).
At 1 year after the dietary-induced weight loss:
- the group without any ongoing treatment (placebo) had regained 6.1kg (for a total weight loss of -6.7% through the entire study)
- the exercise group had regained a little (2.0kg), but kept most of the weight off (for a total weight loss of -10.9% through the entire study)
- the liraglutide group had kept all of the weight off, plus lost an extra -0.7kg (for a total weight loss of -13.4% through the entire study)
- the combination group (liraglutide and exercise) had kept all of the weight off, plus lost an addition -3.4kg (for a total weight loss of -15.7% through the entire study)
At 1 year, compared to no treatment (placebo), all three treatment arms had a significantly lower weight:
- the exercise group was -4.1kg lower in weight
- the liraglutide 3mg group was -6.8kg lower in weight
- the combined liraglutide + exercise group was -9.5kg lower in weight
The people in the exercise groups actually exceeded the exercise requirements a little, doing about 115 minutes (just under 2 hours) of mostly vigorous activity per week (average 119% of requirements in the exercise alone group, and 113% of requirements in the combination group). Most people on liraglutide were able to tolerate the full dose of medication (average dose was 2.8mg per day).
Health benefits were seen in all three active treatment groups. The groups that included exercise enjoyed an improvement in fitness and emotional well being. The groups that included liraglutide enjoyed a reduction in A1C (reflecting better blood sugars), compared with an increase in the placebo group. Only the combination strategy was associated with an improvement in insulin sensitivity and physical functioning. Interestingly, while the heart rate increased by about 4 beats per minute in the liraglutide group (as expected with this and other GLP1 receptor agonists), the combination group did not have an increase in heart rate. Gallstones were uncommon, but slightly more frequent in the liraglutide groups (1 out of 48 participants in the exercise group, 2 out of 49 in the liraglutide group, and 2 out of 49 in the combination group).
The Key Points from this study are:
- A strategy to keep weight off after weight loss is a must. Without a strategy in place, weight will be regained.
- A moderate to vigorous exercise regimen can successfully help keep most weight off after weight loss – provided it is continued long term. (which can be challenging without the support of a clinical trial)
- Weight management medication can successfully help keep weight off after weight loss. As blogged previously, in our 2020 Canadian Obesity guidelines, we recommend weight management medication not only for weight loss, but to maintain weight loss that has been achieved by lifestyle changes.
- Exercise with weight management medication was better than either one alone for healthy weight loss maintenance.
Disclaimer: I have been involved as a principal investigator of trials of liraglutide 3.0mg as an obesity treatment. I receive honoraria as a continuing medical education speaker and consultant from the makers of liraglutide (Novo Nordisk).
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