Fig. 2: Effects of an acute low-protein meal and prolonged protein-restricted diet on circulating FGF21 levels and energy requirements for weight maintenance.
a, Illustration of study 1, in which healthy, lean men ingested a LPHC meal or a habitual HP meal in randomized order followed by a eucaloric LPHC diet for 5 weeks. b, Fasting and postprandial plasma FGF21 level, c, glucose and d, insulin levels. e, Whole-body oxygen uptake. f, RER during the LPHC and HP meal. g, Daily energy provision during the LPHC intervention. h, Fasting plasma FGF21 levels before and after the LPHC intervention. i, Daily number of steps and j, daily measurement of body weight during the LPHC intervention. P values in b–f determined by repeated measures two-way ANOVA/mixed-effects model with Bonferroni multiple comparisons test; in g, i and j, repeated measures one-way ANOVA/mixed-effects model with a Bonferroni post hoc test; in h, two-tailed paired t-test. Asterisk (*) indicates difference between diets in d and g (different from day 0): *P < 0.05, **P < 0.01, ***P < 0.001; # indicates effect of time (or main effect of time in c, e, f and j) in d: ##P < 0.01, ###P < 0.001. All data are presented as mean ± s.e.m. Meal test data in b, c, e, f, n = 9; in d, n = 8 owing to insulin analysis issues for one participant. LPHC diet intervention data in g–j, n = 8, as one participant only completed the meal test.
