A descriptive study of undernutrition, gender and sexual maturation among adolescents in Kilosa District, Tanzania

OBJECTIVE: Undernutrition is a major public health concern and afflicts between 15-30% of adolescents in Sub Saharan Africa. A significant gender difference in adolescent nutritional status has been observed in several developing country studies, with boys appearing to be twice as undernourished as girls. We sought to examine the associations among undernutrition, gender, and sexual maturation in a sample of adolescents from Tanzania.

METHODS: This cross-sectional study examined the nutritional status of 670 individuals aged 10-19 years from 28 villages in Kilosa District, Tanzania. Undernutrition was defined as BMI for Age <5th percentile of the NCHS/WHO reference. Logistic regression models tested associations between gender, sexual maturation, and the outcome variable, undernutrition. We also included an interaction term to represent the cross-product of male and mid-adolescence, a period associated with peak linear growth.

RESULTS: The prevalence of undernutrition in this sample was 25.4% among boys and 15.7% among girls. Undernutrition appeared to be transient during adolescence, with marked improvement in nutritional status after mid-adolescence. Multivariate analyses indicated a moderating effect of mid-adolescence on the nutritional status of males but not females. The odds of being undernourished were significantly greater for mid-adolescent males relative to all other groups.

CONCLUSION: Our findings suggest that undernutrition among adolescent males in this sample might be a function of the rapid growth, physiological changes, and increased nutrient demands associated with sexual maturation. Longitudinal studies are needed to determine whether the gender differential observed in adolescent nutritional status in developing countries has a physiological explanation.