The Effects of Time-Restricted Eating and Alternate-Day Modified Fasting on Interferon-γ and Interleukin-10 Levels in Young Asian Women with Obesity: A Quasi-Experimental Study

Background/Objectives: Obesity induces chronic low-grade inflammation marked by elevated pro-inflammatory cytokines, such as interferon-gamma (IFN-γ), and reduced anti-inflammatory cytokines like interleukin-10 (IL-10), contributing to immune dysregulation. Intermittent fasting (IF) may restore immune balance through metabolic and circadian mechanisms. This study compared the effects of time-restricted eating (TRE) and alternate-day modified fasting (ADMF) on IFN-γ and IL-10 levels in young women with obesity. Methods: A 20-day quasi-experimental study with a pretest–posttest control group design included 23 non-diabetic women with obesity (aged 18–25 years; BMI ≥ 25 kg/m2 according to the Asia-Pacific classification), randomized into control (n = 8), TRE 18:6 (n = 8), and ADMF (n = 7) groups. IFN-γ and IL-10 serum levels were measured pre- and post-intervention using ELISA kits. Results: TRE significantly reduced IFN-γ levels (p = 0.025), while no significant change was observed in the ADMF or control groups. No significant changes were found in IL-10 levels. Conclusions: TRE effectively reduced pro-inflammatory IFN-γ levels without significantly altering anti-inflammatory IL-10 levels, suggesting an anti-inflammatory effect primarily mediated through suppression of IFN-γ rather than IL-10 upregulation. The absence of significant IL-10 changes may reflect complex immunoregulatory dynamics in obesity. ADMF showed no significant immunomodulatory impact. These findings support TRE as a promising non-pharmacologic strategy to attenuate inflammation and improve immune balance in young women with obesity.