September 28, 2022
3 min read
Sun reports no relevant financial disclosures. Please see the full study for all other authors’ relevant financial disclosures.
Adults with obesity — but not those with normal weight — who try to lose weight lower their risk for developing type 2 diabetes regardless of weight-loss strategy, according to study findings published in PLOS Medicine.
In findings from three U.S. cohorts, adults with normal weight who attempted to lose weight did not experience the same health benefits as people with obesity who attempted weight loss. In addition, normal-weight adults who attempted to lose weight had a higher risk for type 2 diabetes with most weight-loss strategies compared with those with normal weight who did not try to lose weight.
“The health consequences of losing a significant amount of body weight intentionally are distinct between lean individuals and individuals with obesity,” Qi Sun, MD, ScD, associate professor in the departments of nutrition and epidemiology at Harvard T.H. Chan School of Public Health and in the Channing Division of Network Medicine at Brigham and Women’s Hospital and Harvard Medical School, told Healio. “It appears that lean individuals, when losing weight, are more likely to gain more weight and have a higher risk of developing diabetes. In contrast, obese individuals will always benefit from losing weight, regardless of which of the common methods used to achieve the weight loss and have less weight gain and lower diabetes risk.”
Researchers analyzed data from the Health Professionals Follow-up Study, the Nurses’ Health Study and the Nurses Health Study II. Adults aged 24 to 60 years without type 2 diabetes, cardiovascular disease or cancer at baseline were included. Weight-loss attempts within 4 years of baseline were self-reported in all three cohorts. Participants reported the amount of weight lost and frequency of intentional weight loss. Methods of weight loss were self-reported. Seven weight-loss strategies included in the study were low-calorie diet, exercise, low-calorie diet plus exercise, commercial weight-loss program, weight-loss pill and a combination of two or more of fasting, a commercial weight-loss program and a weight-loss pill. Adults who did not attempt to lose weight were the reference group in the study.
Any weight-loss strategy linked to higher long-term diabetes risk
There were 104,180 adults included in the study. Of all participants, 53.2% reported intentionally losing at least 4.5 kg of body weight. Of those who intentionally lost weight, 29.2% lost weight through a low-calorie diet and exercise, 27.4% through a commercial weight-loss program, 13.3% through a low-calorie diet alone, 12.6% through fasting, 10.7% through exercise alone, 5.1% through a combination of fasting, a weight-loss program and a weight-loss pill, and 1.9% through a weight-loss pill alone. At 10 years of follow-up, adults who performed any weight-loss strategies had more weight gain compared with the reference group.
During 2.14 million person-years of follow-up, there were 10,149 cases of incident type 2 diabetes. All weight-loss strategies were associated with a higher risk for type 2 diabetes compared with no weight-loss attempt. Adults who used a weight-loss pill had the highest type 2 diabetes risk compared with those who did not attempt to lose weight. (HR = 1.64; 95% CI, 1.41-1.92; P < .001).
Benefits of weight loss for adults with obesity
Among adults with obesity, all weight-loss strategies were associated with less weight gain in the first 4 years of follow-up compared with those who did not try to lose weight, whereas people with normal weight had more weight gain with all weight-loss strategies except exercise compared with those who did not attempt to lose weight. Exercise was associated with a 2% weight gain for those with overweight and a 2.6% weight gain for those with normal weight at 4 years, whereas adults with obesity lost 0.7% of body weight.
Among those with obesity, all weight-loss strategies were associated with lower risk for type 2 diabetes compared with no attempt at weight loss. For people with normal weight, an increased risk for type 2 diabetes was observed for all weight-loss strategies except exercise compared with the reference group.
“Lean individuals, when losing weight, are more likely to lose more lean mass and less fat mass than obese individuals,” Sun said. “As a result, when they regain weight, they continue to regain and accumulate fat mass rather than lean mass. And this excess weight gain, especially fat mass gain, is the culprit for increased diabetes risk.”
Sun said the decision to lose weight should be guided only by medical indications for adults with type 2 diabetes and emphasized the importance of regular physical activity and eating a healthy diet to prevent weight gain.
“We are interested in understanding whether a certain diet can help lean individuals counteract the excess weight gain and higher diabetes risk after weight loss,” Sun said of future research. “We are also interested in finding factors that particularly predict adverse health consequences among lean individuals when they try to lose weight.”
For more information:
Qi Sun, MD, ScD, can be reached at [email protected].