Body mass changes in double-crossover and long-term control mice. (A,B) Body mass curves for female (A) and male (B) mice. Prior to the experiment starting (day −7), when mice were 3 months old there was no difference in body mass or food intake between the groups (P >0.05). A 40% food restriction was initiated in the dietary restricted group on day 0. Data represent means ± SEM from N = 6 to 10 mice/group in the crossover groups and from 280 (at start) to 48 (at the end) mice in the control groups. (C,D) Rates of body mass change with time under the indicated treatments in females (C) and males (D). Rates were calculated by linear regression for time points within an approximately linear range and are means ± SEM. Colors are as in (A) and (B). Asterisks denote significant differences between groups (*P <0.05, **P <0.001 assessed using one-way analysis of variance (ANOVA)/Holm-Sidak).