Effects of testosterone upon feeding in male mice.

Food intake and pattern of feeding were recorded in intact and castrate male mice. Intact adults are larger and eat more than pre-pubertal castrates, due to rapid growth at puberty. Castration in adulthood has little effect upon food intake, but feeding becomes concentrated into large, infrequent meals. The change in meal size appears primary and is reversed by testosterone. During rapid growth at puberty, both meal size and frequency are high. It is suggested that testosterone affects feeding in two ways. Rapid weight gain at puberty leads to high meal size and frequency, but in adulthood meal size is depressed. Meal size in adults is further depressed by stimuli from females, and it is argued in this case that testosterone affects a general mechanism for altering feeding when other activities have a high priority.