Initial adiposity is associated with body composition changes in response to diet-induced weight loss in normal-weight healthy individuals: The first results of the NUTRILEX study

While a significant number of normal-weight individuals are engaged in dieting practices, there is a need to better characterize the composition of weight change during and after weight loss (WL) intervention in this population. The study aimed to examine body composition in response to diet-induced WL and 4-month follow-up in normal-weight adults. Thirty-five participants (23 +/- 4 y, 24 females) joined the laboratory to measure body weight (BW) and body composition using Dual-energy X-ray absorptiometry on 5 occasions: baseline (T0), 3 % WL (T1, n = 32), 6 % WL (T2, n = 18), 1-month follow-up (T3, n = 18), 4-month follow-up (T4, n = 16). BW, fat mass ([FM], kg and %), and lean body mass (LBM) decreased at T1 and T2 compared to T0 (p < 0.01). While the participants with lower initial adiposity lost a lower proportion of FM at T1 and T2 (rho < -0.45, p < 0.05), the rate of WL and WL duration were not associated with changes in body composition. Participants declaring to stop the diet after the intervention significantly regained more BW and LBM, but not FM, from the end of the intervention to T3 (p <0.01) and T4 (p <= 0.01) compared to those who wanted to continue. To conclude, while both FM and LBM tissues were reduced in response to a diet-induced WL, only a major LBM regain was observed after 4 months of follow-up in participants who declared to not continue the diet at the end of the intervention.