A study recently published in The Nutrition Diary 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 of weight regain in response to weight loss and to “personalize nutrition” by identifying the biological factors that influence individual response to weight loss diets.
Excess adiposity is associated with an 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. Measurements of body weight and body mass index (BMI; in kg/m2) do not distinguish between fat mass and lean mass. Individual differences in insulin dynamics may influence changes in body composition in response to energy restriction and consequent weight loss. To better understand these dynamics, researcher David Ludwig (Harvard Medical School) and his colleagues tested the hypothesis that insulin secretion predicts changes in body composition in young and middle-aged adults with high BMI following to significant weight loss.
Using data from 2 large eating trials, participants consumed moderate-carb or very-low-carb calorie-restricted 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 after weight loss. The 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 to those with lower insulin secretions . Similarly, adverse changes in body composition were predicted by higher baseline insulin resistance. 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 results, a better understanding of the biological mechanisms influencing the composition of weight loss and the basis of weight regain could help better characterize those who respond negatively to calorie restriction.
A companion editorial by Mads Hjorth and Arne Astrup (Healthy Weight Center Novo Nordisk Foundation Hellerup, Denmark) provides additional information on the importance of these new findings and how a better understanding of insulin and glucose dynamics can help us move closer to precision dietary management of obesity.
Julia MW 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 after loss of weight in adults with a high BMI, The Nutrition Diaryvolume 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 precise dietary management of obesity?, The Nutrition Diaryvolume 152, issue 3, March 2022, pages 649–650, https://doi.org/10.1093/jn/nxac001.
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