Factors influencing individual variability in high fat diet-induced weight gain in out-bred MF1 mice

Weight changes on HFD ranged from − 1 to 26%, equivalent to − 0.2 g to 10.5 g in absolute mass. Multiple regression models showed that fat free mass (FFM) of the mice before exposure to HFD predicted 12% of the variability in weight gain on HFD (p < 0.001). Also, FI during the first week of HFD feeding predicted 20% of the variability in BM and fat mass (FM) gain 4 weeks later. These data may point to a role for the reward system in driving individual differences in FI and weight gain. Weight gain on the HFD was significantly negatively correlated to weight loss on CR, indicating that animals that are poor at defending against weight gain on HFD, were also poor at defending against CR-induced weight loss. Changes in FM and FFM in response to HFD or CR were not correlated however.