Abstract / Summary
Abstract Purpose Loss of fat-free mass is a frequent adverse effect during energy-restrictive diets. While whole-body electromyostimulation (WB-EMS) mitigates the undesirable loss of fat-free mass during intentional weight loss, not all individuals benefit from WB-EMS. The present study aimed to determine the effects of sex, age, and overweight/obesity status on body mass, fat mass, and skeletal muscle mass (SMM) during a WB-EMS and nutritional intervention in overweight and obese individuals. Methods Altogether, 134 overweight or obese, sedentary participants aged 21–64 years were included in the study. All participants fully complied with the 8-week, 2×20 min.week −1 WB-EMS protocol. Regular dietary counseling was scheduled to reduce energy intake by ≈500 kcal.d −1 , but maintain protein intake. Body composition was determined using bioimpedance analysis. Potential effects of “sex”, “age”, and “overweight/obesity” on changes of the given body composition outcome were analysed using ANCOVA adjusted for baseline differences. Results While no significant effects of age and overweight/obesity status on body mass and composition were observed, body mass and SMM differ significantly between men and women. In detail, women lose significantly more SMM compared with men (− 0.10±0.61 vs. − 0.39±0.73 kg, p<.001, d=.43). Even after adjusting for body mass changes (women: − 4.1±2.3 vs. and men − 3.5±2.2 kg, p=.018), the difference remained significant (p≤.001). Conclusion Although data should be interpreted with caution, small reductions in SMM suggest that WB-EMS is a feasible option for maintaining muscle mass during energy-restricted weight loss. However, this favorable effect seems more pronounced in men compared to women. ClinicalTrials.gov: NCT06584578, date: 09/02/2024.