WEIGHT AT MENARCHE: SIMILARITY FOR WELL-NOURISHED AND UNDERNOURISHED GIRLS AT DIFFERING AGES, AND EVIDENCE FOR HISTORICAL CONSTANCY

Abstract

The mean weight at menarche of 30 undernourished Alabama girls did not differ from that of 30 well-nourished controls, although the undernourished girls attained menarche two years later than controls and at a significantly greater height. This supports the hypothesis that a critical weight triggers menarche. The weight-dependency of menarche, irrespective of a causal relationship, reduces variation in body size at sexual maturity by delaying or advancing the age of sexual maturation as a compensation for environmental or genetic variation. Recent and historical evidence indicates that the mean weight at menarche of Caucasian girls has been about 46 kg. for over a century.