The significance of human growth and maturity is derived from their relationships to the future size, proportions, and composition of the body, and from associations of growth measures with current and future risk factors for serious diseases.

EARLY GROWTH AND LATER GROWTH

Growth status and growth rates at young ages are related to later growth. Tracking of status values, which is usually estimated from age-to-age correlations, is described in Chapter 3. The relationships between the timing of spurts, particularly the pubescent spurt, and body size before and after these spurts are considered together with other effects of maturity in Chapter 3.

Size at birth

In overview, birth weight has only slight relationships to weight, length, BMI, and skinfold thickness during infancy and childhood, but it is negatively correlated with the rates of growth in weight and length during early infancy. Small positive effects of length at birth on stature may persist until adulthood. The effects of birth weight on size during infancy decrease with age. The differences in weight, calculated as Z scores, among groups of infants with different birth weights, decrease markedly to 18 months, but change little from 18 months to 5 years (Binkin et al., 1988). There are low to moderate correlations (r =0.2–0.5) of birth weight with weight in infancy (Boryslawski, 1988; Cole, 1995; Wright et al., 1994) and with BMI and skinfold thicknesses at 2 years and 5 years (Rolland-Cachera et al., 1996).