A mixed-longitudinal study on the pattern of pubertal growth: relationship to socioeconomic status and caloric-intake--IV.

The pubertal growth pattern was observed on 791 girls belonging to upper and low SES. These girls ranged between 7-16 years. The effect of calorie intake on the pubertal growth was also ascertained. The development of breast was first to appear at the age of 8.25 years. It was followed by pubic and axillary hair development. The mean age of menarche was 12 years and 12.8 years for USES and LSES, respectively. The onset of menarche, breast and pubic hair was significantly delayed in LSES girls by 0.8 years. Menarche was found to correlate better with breast development than pubic or axillary hair. The girls on adequate calories showed early onset of breast, pubic hair and axillary hair development and of menarche. Similarly, these girls attained mature stage (adult) of these variables earlier compared to those who were on inadequate calories. However, intermittent developmental stages of pubic hair and axillary hair showed no consistency with intake of calories. The girls on inadequate calories showed approximately one year late onset of breast and pubic hair development. The present observations suggest that the onset of puberty is strongly influenced by environment but its attainment is under the genetical control.