Decreased adipocyte size and lipid of high aerobic capacity rats is associated with protection from steatosis following a 3‐day high fat diet (711.10)

In obese individuals, 60 ‐ 80% possesses hepatic steatosis. We assessed if intrinsic aerobic capacity influences adipose cellularity and hepatic steatosis following an acute high fat diet (HFD). High capacity runner (HCR)/low capacity runner (LCR) rats (n=8), divergent for aerobic capacity, were fed a 45% HFD for days followed by measures of body composition, adipose cellularity/lipid content and liver steatosis. LCR rats have higher percent body fat (%BF), greater average adipocyte size and lipid content, and greater steatosis on control diet compared to HCR. Acute HFD resulted in increased %BF and steatosis in the LCR, while HCR were protected. The HFD increased adipocyte size and lipid in both strains; however, LCR remained higher than HCR. Interestingly, LCR demonstrated a greater distribution of large adipocytes compared to HCR on control diet. HFD resulted in a shift to larger adipocytes in both groups, with LCR demonstrating greater total lipid in this large adipocyte fraction. In conclusion, high aerobic capacity in the HCR results in protection from HFD‐induced hepatic steatosis, which is associated with smaller adipocytes and less lipid per adipocyte than the low aerobic capacity LCR. Grant Funding Source : Supported by NIH DK‐088940 & T32 AR048523