Postnatal weight and height growth velocities at different ages between birth and 5 y and body composition in adolescent boys and girls

Background: Rapid weight gain in the first years of life is associated with adult obesity. Whether there are critical windows for this long-term effect is unclear. Objective: The objective was to study anthropometric measures in adolescence by sex according to weight and height growth velocities at different ages between birth and 5 y. Design: Anthropometric measures, including fat and fat-free mass by bipodal impedancemetry, were measured in 468 adolescents aged 8-17 y. We retrospectively collected early infancy data and individually estimated weight and height growth velocities in 69.4% of them using a mathematical model. Associations between birth variables, growth velocities, and anthropometric measures in adolescence were studied. Results: Weight growth velocity at 3 mo was associated with overweight (odds ratio for a 1-SD increase: 1.52; 95% CI: 1.04, 2.22), fat mass, and waist circumference in adolescence in both sexes and with fat-free mass in boys (r = 0.29, P < 0.001) but not in girls (r = -0.01,NS). Weight growth velocities after 2 y were associated with all anthropometric measures in adolescence, in both sexes. Between 6 mo and 2 y, weight growth velocities were significantly associated only with adolescent height in boys; in girls, associations with fat mass in adolescence were weaker. Conclusion: Our results support the hypothesis of 2 critical windows in early childhood associated with the later risk of obesity: up to 6 mo and from 2 y onward. The study of the determinants of growth during these 2 periods is of major importance for the prevention of obesity in adolescence.