A, food intake over a 24 h period (n = 2–5 mice per group; means with the same lowercase letter are not significantly different from each other, Bonferroni test, P < 0.05). B, RER, (C) spontaneous activity and (D) energy expenditure were measured ∼12 weeks after the start of the dietary intervention (n = 4–5 mice per group; means with the same lowercase letter are not significantly different from each other, Tukey–Kramer test following ANOVA, P < 0.05). E, FGF21 was measured in the plasma of mice following an overnight fast (n = 4 mice per group; means with the same lowercase letter are not significantly different from each other, Tukey–Kramer test following ANOVA, P < 0.05). F, Fgf21 gene expression in the liver of mice following an overnight fast was assessed by quantitative PCR (n = 8–9 mice per group; #P < 0.1 vs. WD Control AA, Dunnett's test following ANOVA). Error bars represent the SE.