Comparative Effects of Intermittent Fasting and Swimming Exercise on Metabolic Markers and White Adipose Tissue Browning in High-Fat Diet-induced Obese Mice

This study aimed to compare the effects of intermittent fasting (IF) and swimming exercise (SE) on metabolic markers and white adipose tissue (WAT) browning in high-fat diet (HFD)-induced obese mice.METHODS: Forty male C57BL/6J mice (six weeks old) were randomly assigned to four groups: normal chow diet (CON), high-fat diet (HFD), HFD with intermittent fasting (HFD+IF), and HFD with swimming exercise (HFD+SE).The IF protocol consisted of a 48-h feeding and 24-h fasting cycle, while SE was performed for 90 minutes per day, five days per week, at 321C for eight weeks.Body weight, glucose, triglycerides, serum insulin, and HOMA-IR were analyzed.The protein expression of AMPK, PGC-1, and UCP1 in skeletal muscle and subcutaneous WAT was evaluated using Western blotting.RESULTS: After eight weeks, the HFD group showed significant increases in body weight, triglycerides, and HOMA-IR compared with the CON group (p<.05).Both IF and SE interventions partially ameliorated these metabolic impairments.IF significantly increased AMPK expression in the gastrocnemius muscle and UCP1 in subcutaneous WAT, whereas SE significantly elevated PGC-1 expression in skeletal muscle.CONCLUSIONS: These findings suggest that IF improves metabolic health primarily through activation of the AMPK-UCP1 signaling pathway, while SE promotes mitochondrial biogenesis via PGC-1 upregulation.Both interventions exert anti-obesity effects through distinct molecular mechanisms, and their combination may offer a synergistic strategy for preventing obesity-related metabolic disorders.