Water intakes of lactating women.

Women are commonly advised to increase their water intake during lactation, even though empirical data describing fluid intakes of successfully lactating women is lacking. Water intake from solid food and beverage was determined from 135 food records completed by 26 lactating women who had fully breast-fed their infants for 3 to 4 mo. Inter-subject variability in total water intake, food water, and beverage was significantly greater (one-way analysis of variance, p less than 0.01) than intra-subject variability. Total water consumption/subject (mean +/- SEM) was 2860 +/- 108 g/day, with 640 +/- 48 g/day from food and 2220 +/- 110 g/day from beverage. One-third of the subjects consumed less than the 1 g of water/kcal of energy need described in the current Recommended Dietary Allowances. Thus, it appears that while many successfully lactating women consume large quantities of water, many do not consume enough to satisfy theoretical recommendations. Results indicate that estimation of water intake must include water available in food as well as in beverage.