individual participated in leisure activity that day). It is reasonable to assume that these two populations differed in physical activity levels on the surveyed day; however, data are not available to document this difference. The more active groups had a greater daily total water intake by approximately 0.6 and 0.5 L for the men and women, respectively.

There are few data concerning water intake during gestation or during lactation. NHANES III surveyed 341 pregnant and 98 lactating women (Appendix D). The median daily intake of drinking and beverage water was estimated to be 2.3 L, and the intake of water from food was 0.6 L, providing a total intake of approximate 2.9 L for total water from foods, beverages, and drinking water. CSFII surveyed 124 women listed as pregnant or lactating (Appendix E). The median daily intake of drinking and beverage water was estimated to be 1.8, and the intake of water from food was 0.7, providing a total water intake of approximately 2.5 L from foods, beverages, and drinking water. CSFII data were not separated as to period of gestation nor to gestation versus lactation.

Water intoxication can lead to hyponatremia, which can be life threatening. This occurs occasionally in psychiatric patients (psychogenic polydipsia) and needs to be addressed quickly before serious side effects occur. Water intoxication and death from acute water toxicity have also been reported in nonpsychiatric situations in which voluntary consumption of excess amounts occurred