JMIR Publications

ABSTRACT

Background:

Lifestyle interventions are a crucial component of weight loss programs, yet digital, personalized, and theory- and evidence-based lifestyle interventions remain limited.

Objective:

To investigate the impact of a combination of various dietary approaches and exercise, based on digital technology, on the body composition of obese college students.

Methods:

From October to December 2023, an intervention study was conducted, enrolling 129 obese university students from a university in Nanchang, China. All participants voluntarily selected one of the following dietary approaches: twice-per week fasting diet (TWF), low-calorie diet group (LCD), or 16/8 time-restricted feeding group (TRF). The exercise, self-monitoring, and feedback were consistent across the three groups. The research team provided an 8-week intervention. The primary outcome was body composition (muscle, fat, and water content). Data were collected at baseline, 4 weeks, and 8 weeks. Repeated measures analysis of variance was used for within-group comparisons, one-way analysis of variance for between-group comparisons, and independent samples t-tests for gender comparisons.

Results:

Ultimately, 127 participants completed the study, with two participants from the TRF+EX group dropping out.After the 8-week intervention, body composition improved for all three groups of participants. In terms of muscle indices, there was no change in lean body mass in the TRF group when comparing the 8-week data to the 4-week data, with a slight increase observed in females, showing no statistical significance for both males (P=.909) and females (P=.944). Regarding fat indices, after 8 weeks of intervention, males in the TWF group showed greater reductions in body weight (MD -5.233; P < .001) and visceral fat mass (MD -0.556; P < .003) compared to the other two groups. Females in the LCD group exhibited greater reductions in body weight (MD -5.662; P < .001) and visceral fat mass (MD -1.031; P = .001) compared to the other groups. In moisture indices, after 8 weeks of intervention, both males (MD -1.411; P = .001) and females (MD -0.588; P = .057) in the TWF group experienced a smaller decrease in body moisture compared to the other two groups.

Conclusions:

Research indicates that the combination of various dietary approaches with exercise has distinct effects on body composition. In muscle indices, the TRF group experienced a rapid decrease in lean body mass at four weeks, which remained unchanged at eight weeks, with a slight increase observed in females. In fat indices, males in the TWF group achieved better fat reduction, while females in the LCD group had superior fat loss effects. Regarding moisture indices, both males and females retained more body water in the TWF group. Clinical Trial: Chinese Clinical Trial Registry ChiCTR2300073166