This study will investigate the nutritional status and energy balance of a sample of adult Swazi women who are living in an African environment that is characterized by suboptimal nutrition and heavy workloads. The investigators hypothesize that balance between energy intake and expenditure will vary by season, with expenditure exceeding intake during periods of peak labor and low food supply. The question of how work output is related to its energetic cost is generally considered one of the more importantproblems in adaptive human population biology today.
