Effects of intermittent fasting on blood glucose, lipid profile and renal-hepatic biomarkers of streptozotocin-induced rats fed with a high-fat diet

Abstract

Objectives: Intermittent fasting (IF) is increasingly adopted as a dietary strategy for managing diabetes mellitus, yet its effects on vital metabolic organs such as the liver and kidneys remain unclear. This study investigated the impact of different IF regimens on hepatic and renal functions in streptozotocin-induced diabetic rats.

Methods: Fifty male Wistar rats were divided into five groups (n=10): control (group 1), diabetic (group 2), and three diabetic groups subjected to distinct IF protocols with a high-fat diet—time-restricted feeding (group 3), alternate-day fasting (group 4), and the 5:2 diet (group 5). The experiment lasted four weeks. Weekly body weight and blood glucose (BG) levels were monitored. Serum lipid profile, liver enzymes (ALT, AST, ALP), renal markers (urea, creatinine), and histopathological changes were assessed using standard methods. Data were analysed by one-way ANOVA at p<0.05.

Results: All groups gained weight, but BG and biochemical parameters varied significantly. Groups 2 and 5 showed the greatest BG reduction (104.0 ± 10.23 to 63.3 ± 15.37 mg/dL and 93.8 ± 6.65 to 42.8 ± 4.72 mg/dL, respectively; p=0.05). The 5:2 diet produced the lowest total cholesterol (3.0 ± 0.06 mg/dL), AST (56.5 ± 7.92 U/L), and urea (1.43 mg/dL), with elevated HDL and creatinine. Histological analysis showed varying degrees of hepatic alteration across IF groups.

Conclusion: Intermittent fasting, particularly the 5:2 regimen, improved glycemic and lipid profiles despite mild hepatic and renal stress. IF may support metabolic regulation in diabetes, though dietary fat modification and cautious fasting durations are advised to protect organ integrity.