Previously submitted to: JMIR mHealth and uHealth (no longer under consideration since Feb 19, 2026)
Date Submitted: Jun 16, 2025
Open Peer Review Period: Jun 26, 2025 - Aug 21, 2025
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Self-Managed Weight Loss Enhances Skeletal Muscle Rate in Overweight and Obese Individuals via mHealth App
ABSTRACT
Background:
Obesity is a major risk factor for many chronic diseases. However, weight loss benefits may diminish if accompanied by skeletal muscle loss.
Objective:
This study evaluates muscle changes during mobile health (mHealth) app-based weight loss in overweight/obese individuals and identifies muscle gain predictors.
Methods:
Among the 38,209 participants achieving weight loss via the mHealth app were divided into two groups: weight loss without muscle gain (WL-NG) and with muscle gain (WL-MG, defined by ≥ 5% skeletal muscle rate [SMR] increase over 6 months). Women showed slower fat loss (8.36, IQR: 7.04 vs -12.24, IQR: 10.00%, P < 0.0001) and muscle gain (4.46, IQR: 3.77 vs 4.64, IQR: 3.85%, P < 0.001) than men, despite higher measurement frequency and weight-loss rates. WL-MG participants had lower baseline age/SMR but higher baseline BMI/body fat (PBF) versus WL-NG (P < 0.001). Weight-loss rate, fat-loss rate, and measurement frequency were higher in WL-MG (P < 0.0001). PBF change rate strongly correlated with SMR changes (woman: rs = -0.977, P < 0.0001; man: rs = -0.936, P < 0.0001). Multivariable regression identified higher measurement frequency as the strongest muscle-gain predictor (OR = 1.030, 95% CI: 1.028–1.031, χ²-df = 1658.983, P < 0.0001).
Results:
In conclusion, this study demonstrates that during the weight loss process, men tend to lose more fat and gain more muscle than women. The rate of weight change was negatively correlated with the rate of SMR change.
Conclusions:
Frequent mHealth self-monitoring enhances weight loss efficacy and muscle preservation, highlighting its critical role in optimizing body composition.
Citation
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