LACTATION PERFORMANCE IN RURAL WOMEN WITH LOW BIOAVAILABILITY OF NUTRIENTS FROM THE HABITUAL DIET

Metabolizable energy (ME) and apparent nitrogen, fat and energy bioava ilability from the habitual diet were measured in a group of lactating women from a Mexican rural community. Food intake was estimated in 40 women, age 24+/-3 y 3-5 m postpartum, body weight 48.7+/-5.4 kg and h eight 148+/-5 cm. Habitual diet was predominantly from vegetable sourc es based on maize (tortillas), beans, tomato, onion and chili. The dai ly intake was: 2224+/-336kcal energy, 47.8+/-7.0g protein, 44.7+/-11.3 fat and 408+/-70 g carbohydrates. Ten women were studied in balance c onditions and consuming a controlled diet similar to their habitual di et. ME and apparent energy, nitrogen and fat availability were measure d by metabolic balance. Milk output was measured by the test-weighing infant method and milk samples representative of 24-h were obtained fo r chemical analysis. Apparent digestibility of energy was 87+/-1.4%, f rom nitrogen 68.4+/-3.1% and 65.8+/-3.7 from fat. Measured ME was 1940 kcal/day. Metabolizable energy from the habitual diet by the marginal ly nourished lactating group was lower than the energy recommended all owance during lactation. Macronutrient's availability from the habitua l diet was similar to that found in population with intake of predomin antly vegetable diets and high dietary fiber content.