Figure 4.
The effects of variable meal size (left) and energy availability (right) on the plasma concentrations of total ghrelin (top) and leptin (bottom) under the experimental conditions described in Fig. 1. Plasma ghrelin concentration was rapidly influenced by energy availability as the increases in the small-meal (Fdf4,36 = 13.23; P < 0.0001) and exercise trials (Fdf4,36 = 5.28; P < 0.002) were abolished by TPN. Plasma leptin concentration slowly and progressively increased in response to reduced energy availability caused by small meal (Fdf4,36 = 48.06; P < 0.0001) and exercise (Fdf4,36 = 39.08; P < 0.0001), and this response was abolished by TPN.