1143-P: Early Aged Mice Stay Metabolically Stable with High-Fat Diet

The relationship between obesity, aging, and the risk of metabolic diseases is a crucial area of study. This research focuses on understanding how aging influences the body's response to high-fat diet (HFD) consumption and its subsequent impact on metabolic health. Our hypothesis posits that aging significantly affects how the body adapts to HFD intake, potentially improving metabolic outcomes. To explore this, we conducted a study using mice of varying ages (4, 6, 8, and 10 weeks old, with 6-8 mice per age group). Over a period of 16 weeks, these mice were fed either a standard chow diet or an HFD. Our findings indicate that older mice (aged) demonstrate a more rapid weight gain in response to HFD compared to younger (early-aged) mice. Interestingly, younger mice appeared to be protected against HFD-induced obesity. Additionally, adipose tissues from younger mice showed fewer inflammatory markers. We also investigated the characteristics of non-alcoholic fatty liver disease (NAFLD), including fatty deposition, lesions, atypical yellowish coloration, and enlargement. These were notably absent in younger mice consuming HFD. Further analysis involved staining liver sections with hematoxylin and eosin (H&E) and Oil Red O to assess lipid accumulation. Results revealed a higher presence of lipid vacuoles in the livers of older mice compared to their younger counterparts on an HFD. Consistent with increased adiposity, fat accumulation in the liver, and inflammation, older mice exhibited impaired glucose tolerance and reduced insulin sensitivity compared to younger mice fed the same diet. In conclusion, our study unveils a significant link between the body's adaptations during early aging and its metabolic responses to HFD. These findings suggest potential avenues for preventing obesity and its associated complications, particularly those exacerbated by overnutrition. This research contributes valuable insights to the field, highlighting the importance of age as a factor in dietary and metabolic health.