Weight loss strategies, weight change, and type 2 diabetes in US health professionals: A cohort study

Abstract

Background Weight loss is crucial for disease prevention among individuals with overweight or obesity. This study aimed to examine associations of weight loss strategies (WLSs) with weight change and type 2 diabetes (T2D) risk among US health professionals. Methods and findings This study included 93,110 participants (24 to 60 years old; 11.6% male) from the Nurses’ Health Study (NHS), NHSII, and Health Professionals Follow-Up Study (HPFS) cohorts who were free of T2D, cardiovascular disease, and cancer at baseline (1988 for NHS/HPFS and 1989 for NHSII) for analyses of weight change and 104,180 (24 to 78 years old; 14.2% male) for T2D risk assessment. WLSs used to achieve an intentional weight loss of 4.5+ kg were collected in 1992 (NHS/HPFS)/1993 (NHSII) and grouped into 7 mutually exclusive categories, including low-calorie diet, exercise, low-calorie diet and exercise, fasting, commercial weight loss program (CWLP), diet pills, and FCP (selected at least 2 methods from fasting, CWLP, and pill). The reference group was participants who did not attempt to lose weight. Generalized estimating equations and Cox regression were applied to estimate up to 10-year weight change trajectory and incident T2D risk through 2016 (NHS/HPFS)/2017 (NHSII), respectively. The associations of WLSs with weight change and T2D risk were differential by baseline body weight (Pinteraction 0.99) for FCP] and a lower T2D risk [hazard ratios (HRs) ranging from 0.79 (0.66 to 0.95; P = 0.04) for exercise to 0.87 (0.66 to 1.13; P = 0.30) for pill]. Such a pattern was less clear among overweight individuals: the difference of weight change varied from −2.5% (−3.0% to −2.1%; P Conclusions The current study showed that individuals with obesity who attempted to lose weight, regardless of the WLSs used, tended to gain less body weight and have a lower diabetes risk. In contrast, lean individuals who intentionally lost weight tended to gain more weight and have a higher diabetes risk. These data support the notion that intentional weight loss may not be beneficial for lean individuals and the use of WLSs for achieving weight loss shall be guided by medical indications only. Keyi Si and colleagues investigate associations of weight loss strategies with weight gain and type 2 diabetes in health professionals in the US. Author summary Why was this study done? Weight control is one of the primary and effective strategies for the prevention and management of obesity and related chronic diseases. Trying to lose weight is common not only among overweight individuals or those with obesity, but also among lean individuals. Long-term weight change and risks of developing type 2 diabetes (T2D) following various weight loss strategies (WLSs) are understudied. What did the researchers do and find? Up to 10-year weight change and 24-year T2D risk were compared between individuals who lost 4.5+ kg (10+ lbs) through various WLSs (low-calorie diet, exercise, low-calorie diet and exercise, fasting, commercial weight loss program (CWLP), diet pills, or a combination of the last 3 strategies collectively named as FCP) and those who did not attempt to lose weight. Association of WLSs with weight change and T2D risk varied by baseline body mass index status: individuals with obesity who lost 4.5+ kg intentionally were likely to have less weight gain within 4 years since baseline and lower risk of T2D during 24 years of follow-up, regardless of WLS, but the beneficial associations were attenuated in individuals with overweight and even inverted in lean individuals. Of all WLSs, exercise was associated with the least weight gain and the lowest T2D risk among individuals with obesity. Approximately 15.6% to 46.8% of the association between WLSs and the T2D risk was attributable to body weight changes after weight loss attempts. What do these findings mean? Individuals with obesity may benefit from intentional weight loss regardless of the methods used to achieve the weight loss, whereas lean individuals may not enjoy the same health benefits from intentionally losing a significant amount of body weight. These data suggest that the use of weight loss methods for achieving weight loss should be guided by medical or health indications.