Effects of Intermittent Fasting on Inflammatory Biomarkers and Metabolic Health in Overweight Adults: A Randomized Controlled Trial

Abstract

Background: Chronic low-grade inflammation is a hallmark of obesity and contributes to insulin resistance and cardiometabolic complications. Intermittent fasting (IF) has been proposed as a dietary strategy to improve metabolic health, but its effect on systemic inflammation remains underexplored. Objective: To evaluate the impact of a 12-week intermittent fasting regimen on inflammatory biomarkers, insulin sensitivity, and lipid profiles in overweight adults. Methods: Eighty overweight participants (BMI 27–32 kg/m²) were randomized into two groups: (1) Intermittent Fasting (16:8), fasting for 16 hours and eating within an 8-hour window daily, and (2) Control group, following standard diet advice. Blood samples were collected at baseline and after 12 weeks to assess high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), fasting glucose, HOMA-IR, and lipid profile. Anthropometric parameters were also recorded. Results: After 12 weeks, the IF group showed significant reductions in hs-CRP (−28%, p < 0.01), IL-6 (−21%, p < 0.05), and TNF-α (−17%, p < 0.05) compared to controls. Fasting glucose decreased by 12% and HOMA-IR improved by 18% in the IF group (p < 0.01). HDL cholesterol increased (+9%) and triglycerides decreased (−15%) compared to controls. Body weight and BMI decreased significantly in the IF group (−5.4 ± 1.2 kg vs −1.8 ± 0.9 kg in controls, p < 0.001). Conclusion: A 12-week intermittent fasting regimen improves inflammatory status, insulin sensitivity, and lipid profiles in overweight adults. IF may be a promising non-pharmacological intervention to reduce obesity-related cardiometabolic risk.

Keywords: Intermittent Fasting, Inflammation, Insulin Resistance, Obesity, Metabolic Health