A newly released study in The Journal of Nutrition reported that individual differences in baseline insulin dynamics predicted changes in body composition independent of weight loss. These findings may help to better understand the basis for weight regain in response to weight loss and “personalize nutrition” by identifying biological factors that influence individual response to weight loss diets.
Excess adiposity is associated with increased risk of weight-related mortality. However, current recommendations for obesity management often focus more on body weight with less attention given to body composition. Measures of body weight and body mass index (BMI; in kg/m2) do not discriminate between fat mass and lean mass. Individual differences in insulin dynamics may influence changes in body composition in response to energy restriction and subsequent weight loss. To better understand these dynamics, researcher David Ludwig (Harvard Medical School) and colleagues tested the hypothesis that insulin secretion predicts body composition changes in young and middle-aged adults with high BMI following major weight loss.
Using data from 2 large feeding trials, participants consumed calorie-restricted moderate-carbohydrate or very-low-carbohydrates diets to produce 12-18% weight loss in ~14 weeks or 10-14% in ~10 weeks, respectively. Insulin secretion and insulin resistance were measured at baseline. Body composition was determined at baseline and post-weight loss. Percentages of fat mass, lean mass, and trunk fat mass relative to total body weight were calculated.
Insulin secretion predicted adverse changes in body composition independent of total weight loss. Participants with higher insulin secretions lost less weight as fat mass, lost more weight as lean mass, and had greater central adiposity compared with those with lower insulin secretions. Similarly, adverse body composition changes were predicted by higher insulin resistance at baseline. These results suggest that baseline differences in insulin dynamics may influence changes in body composition independent of weight loss. Although future studies are needed to confirm these exploratory findings, a better understanding of the biological mechanisms influencing the composition of weight loss and basis for weight regain may help better characterize those that respond adversely to calorie restriction.
A companion editorial by Mads Hjorth and Arne Astrup (Healthy Weight Center Novo Nordisk Foundation Hellerup, Denmark) provides further insights of the significance of these novel findings and how a better understanding of insulin and glucose dynamics may help bring us closer to precision dietary management of obesity.
References
Julia M W Wong, Shui Yu, Clement Ma, Tapan Mehta, Stephanie L Dickinson, David B Allison, Steven B Heymsfield, Cara B Ebbeling, David S Ludwig, Stimulated Insulin Secretion Predicts Changes in Body Composition Following Weight Loss in Adults with High BMI, The Journal of Nutrition, Volume 152, Issue 3, March 2022, Pages 655–662, https://doi.org/10.1093/jn/nxab315.
Mads F Hjorth, Arne Astrup, Can Insulin and Glucose Dynamics Bring Us Closer to Precision Dietary Management of Obesity?, The Journal of Nutrition, Volume 152, Issue 3, March 2022, Pages 649–650, https://doi.org/10.1093/jn/nxac001.
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