Puberty and observed energy intake: boy, can they eat!

Abstract

Anecdotal reports suggest that adolescent males consume large quantities of food to meet the growth demands of pubertal development. However, limited experimental data exist to support this impression. The objective was to measure energy intakes of youth at different pubertal stages. Participants were 204 volunteers (50.5% male) aged 8-17 y. Pubertal development was categorized by physical examination into prepuberty (males: testes < 4 mL; females: Tanner breast stage 1), early-mid puberty (males: testes = 4-12 mL; females: Tanner breast stages 2-3), or late puberty (males: testes >12 mL; females: Tanner breast stages 4-5). Energy intake was measured as consumption from a 9835-kcal food array during 2 lunch time meals. Males consumed more energy than did females across all pubertal stages (P < 0.001). Intake increased with pubertal development (P < 0.001), but the timing and magnitude of change varied by sex (P = 0.02). Males' unadjusted energy intake was greater in late puberty (mean +/- SE: 1955 +/- 70 kcal) than in prepuberty (1287 +/- 90 kcal) or early-mid puberty (1413 +/- 92 kcal) (P < 0.001). Females' unadjusted energy intake tended to be lower among prepubertal girls (905 +/- 140 kcal) than among females in early-mid puberty (1278 +/- 82 kcal, P = 0.07) or late puberty (1388 +/- 68 kcal, P = 0.01). After adjustment for fat-free mass, fat mass, height, overweight status, race, and meal instruction, the main effect of sex (P < 0.001) remained significant, but the effect of puberty was not significant (P = 0.66). The observed intake patterns are congruent with known sexual dimorphisms for body composition, peak growth velocity, and pubertal development. Consistent with their higher energy requirements, males can consume significantly larger amounts of food than females, especially during later puberty. This trial was registered at clinicaltrials.gov as NCT00320177.