Effects of time-restricted feeding and walking exercise on the physical health of female college students with hidden obesity: a randomized trial

Time-Restricted Eating and Bone Health: A Systematic Review with Meta-Analysis

Time-restricted eating (TRE) has emerged as a dietary strategy that restricts food consumption to a specific time window and is commonly applied to facilitate weight loss. The benefits of TRE on adipose tissue have been evidenced in human trials and animal models; however, its impact on bone tissue remains unclear. To systematically synthesize and examine the evidence on the impact of TRE on bone health (bone mineral content (BMC), bone mineral density (BMD), and bone turnover factors), PubMed, Scopus, Cochrane CENTRAL, and Web of Science databases were systematically explored from inception to 1 October 2023 searching for randomized controlled trials (RCTs) aimed at determining the effects of TRE on bone health in adults (≥18 years). The Cochrane Handbook and the PRISMA recommendations were followed. A total of seven RCTs involving 313 participants (19 to 68 years) were included, with an average length of 10.5 weeks (range: 4 to 24 weeks). Despite the significant weight loss reported in five out of seven studies when compared to the control, our meta-analysis showed no significant difference in BMD (g/cm2) between groups (MD = -0.009, 95% CI: -0.026 to 0.009, p = 0.328; I2 = 0%). BMC and bone turnover markers between TRE interventions and control conditions were not meta-analyzed because of scarcity of studies (less than five). Despite its short-term benefits on cardiometabolic health, TRE did not show detrimental effects on bone health outcomes compared to those in the control group. Nevertheless, caution should be taken when interpreting our results due to the scarcity of RCTs adequately powered to assess changes in bone outcomes.

Combined versus independent effects of exercise training and intermittent fasting on body composition and cardiometabolic health in adults: a systematic review and meta-analysis

INTRODUCTION AND AIM

Exercise training (Ex) and intermittent fasting (IF) are effective for improving body composition and cardiometabolic health overweight and obese adults, but whether combining Ex and IF induces additive or synergistic effects is less well established. We therefore, performed a systematic review and meta-analysis to compare the combined versus independent effects of Ex and IF on body composition and cardiometabolic health in adults.

METHOD

An electronic search was conducted in three main online databases including PubMed, Web of Science, and Scopus, from inception to March 9, 2023 for studies involving Ex plus IF trials versus standalone Ex and/or IF interventions in adults. Interventions had a duration of ≥ 2 weeks. Standardized (SMD) or weighted mean differences (WMD) and 95% confidence intervals were calculated in order to compare effects on body weight, body mass index (BMI), body fat lean body mass (LBM), visceral fat, and waist circumference. For cardiometabolic health, outcomes included fasting glucose, insulin, total cholesterol (TC), low-density lipoprotein cholesterol (LDL), triglycerides (TG), high-density lipoprotein cholesterol (HDL), systolic (SBP) and diastolic (DBP) blood pressure, and VO2max/peak.

RESULTS

Ex plus IF decreased body weight [WMD: -3.03 kg (95% CI: -3.44 to -2.61), p = 0.001], BMI [WMD: -1.12 kg.m2 (95% CI: -1.28 to -0.95), p = 0.001], body fat [SMD: -0.72 (95% CI: -1.23 to -0.21), p = 0.005], visceral fat [SMD: -0.34 (95% CI: -0.63 to -0.05), p = 0.01], and waist circumference [WMD: -2.63 cm (95% CI: -4.16 to -1.11), p = 0.001] more than Ex alone. However, changes in body composition and cardiometabolic health markers were not significantly different for Ex plus IF when compared with IF alone, with the exception of VO2max/peak [SMD: 0.55 (95% CI: 0.14 to 0.97), p = 0.009].

CONCLUSION

We demonstrate that a combination of Ex and IF produces superior changes in body composition, but not in markers of cardiometabolic health when compared with Ex or IF alone. Ex plus IF could therefore be effective for weight and fat loss but has no additive or synergistic effects for other cardiometabolic health markers.