ABSTRACT
BACKGROUND: Seasonality has been recognized as a key determinant of human energy balance, especially in low-income countries. OBJECTIVE: The objective was to test the hypothesis that, in rural Bangladesh, different age and sex groups adapt similarly to seasonal changes in energy intake (EI). DESIGN: A prospective study was carried out in 2 rural Bangladeshi villages in the lean and peak seasons. Data on anthropometric measures (weight, height, and midupper arm circumference) and dietary food intake (collected with the use of a 24-h food weighing method) were obtained from all subjects from 304 households. RESULTS: The average EI increased from a least-squares mean (+/- SE) of 7.87 +/- 0.10 MJ x person(-1) x d(-1) in the lean season to 9.47 +/- 0.13 MJ x person(-1) x d(-1) in the peak season. In children and adolescents aged < 18 y of age, the prevalence of underweight (weight-for-age) was not significantly different (56%) in the 2 seasons. Among adults, a significantly higher prevalence of chronic energy deficiency [body mass index (in kg/m(2)) < 18.5] was observed in the peak season (67%) than in the lean season (61%), despite a higher EI in the peak season. Other determinants of seasonal nutritional status are presented. CONCLUSIONS: Seasonal fluctuations in EI were substantial in all age and sex groups. Children and adolescents showed no significant seasonal changes in the prevalence of underweight, which indicated that they adapted to changes in EI. In adults, the season in which EI was high coincided with average weight loss, which indicated that adults did not adapt fully to seasonal fluctuations in EI and that seasonal energy expenditure is probably a major determinant of nutritional status.
