The present grant proposal will study energy-nutrition relations in urban poor women using epidemiological methods. We have long been engaged in the study of the functional consequence of chronic malnutrition in Columbia, in adult males in relation to work capacity and productivity and in school- aged boys in relation to growth and work capacity. Studies are currently underway on the effects of dietary interventions on the daily patterns and total energy expenditures of normal and undernourished boys and girls, 6-16 years of age. Practically no data exist on the ways in which poor women in developing countries adapt their daily pattern of or total daily energy expenditures in the face of chronic low energy intakes and their multiple responsibilities within the family. The proposed studies will be carried out in Cali, Columbia. The specific hypotheses to be tested are; 1) low nutritional intakes are compensated by avoidance of high energy-expenditure activity; 2) Total daily energy expenditure is directly related to nutritional status; 3) the muscular efficiencies of women with inadequate nutritional intakes are the same as those of women with adequate diets. The study will also; 1) assess changes in nutritional intake and total daily energy expenditure during pregnancy and lactation; 2) compare energy expenditure patterns of women with adequate and inadequate nutritional intake but similar activity schedules; 3) determine priorities of energy expenditure in situations of multiple time demands; 4) obtain several anthropometric measurements of the children of the subjects to assess mothers. The measurements of total daily energy expenditure will be carried out be a combination of a new application of the heart rate method (recently validated in whole body calorimeter measurements) and basal metabolic rate; nutritional intake will be determined by recall and nutritional status by anthropometry). The latter will involve the establishment of descriptive values for target population during the first year of study. Physical condition and efficiencies in standardized laboratory and common household tasks will be measured, as well as time distribution associated with energy expenditure. Measurements will be carried out in groups of women; non-pregnant at home and working, pregnant at home and working and lactating women. Each subject will be studied on 3 occasions separated by about 3 months to cover different seasons and to allow for measurements of the growth performance of their children. The results will provide much needed information on how energy expenditures of third-world urban women related to their nutritional intakes, and will have important implications for policy makers.