Diet-induced changes in body mass and fat levels in control and high-fat fed mice. (a) High-fat (HF)-fed mice showed much greater levels of variation in body mass, body fat, and visceral fat compared with control mice. The same individual HF mice (denoted numerically) fell in either the upper half or lower half of the bar plot distributions for these variables. Those mice in the upper half of the distribution were classified as high gainers (HG), and those in the lower half were classified as low gainers (LG). (b) Body mass in HG mice was greater than controls after 4 weeks of HF feeding compared with 37 weeks of HF feeding in LG mice (P < 0.05). Bar indicates duration of HF feeding. Data shown as mean ± standard error of the mean.