The effects of time-restricted feeding on early vascular, liver, and renal structural changes, oxidative stress, and inflammation in obese rats

Cardiovascular disease remains a leading global cause of death, highlighting the need for new strategies to improve cardiovascular health. Time-restricted feeding (TRF), which limits daily food intake to a specific window, has shown promise in improving metabolic health and supporting weight control. This study investigated the effects of TRF in an obese rat model induced by a high-fat diet (HFD), focusing on early vascular, liver, and kidney structural changes, as well as oxidative stress and inflammation. Thirty male Sprague Dawley rats were assigned to five groups: a normal diet group (NOR), a normal chow with TRF (NOR + TRFNC), a continued HFD group (OB), an HFD with TRF group (OB + TRFHFD), and a group switched to TRF with normal chow (OB + TRFNC). Obesity was induced in three groups over six weeks, followed by a six-week intervention phase. TRF involved fasting for 16 h daily (5:00 p.m. to 9:00 a.m.). TRF led to improved lipid profiles and atherogenic indices in obese rats, regardless of diet. Elevated liver enzymes, alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) in obese rats were normalized by TRF. Additionally, TRF increased vascular superoxide dismutase (SOD) and decreased malondialdehyde (MDA), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α). Histological analysis showed that fat infiltration and steatosis in the liver were reduced by TRF. Renal and vascular structures also showed improvement. In conclusion, TRF exhibits anti-atherosclerotic effects, likely due to reduced vascular oxidative stress, inflammation, improved liver and kidney function, and better atherogenic profiles. These benefits were supported by histopathological findings in hepatic and renal tissues.