Water intake in women adopting increased physical activity: Can it help weight control?

Regular fluid intake is essential for health. Physical activity increases the body's water requirements. Does increased physical activity increase intake of water-rich foods as well as more beverages? Is exercise-induced water intake, in turn, associated with nutrient changes and with weight status at follow-up?

Water consumption patterns were observed among a group of 142 middle-class African American women assigned to the intervention condition of an eight-week gym-based intervention study. 24-hour dietary recalls were obtained up to three times in 8-week intervention period. BMI was assessed at 2-months, 6-months and 12-months follow-up.

Results: As designed, the intervention increased physical activity and aerobic fitness. Parallel increases in water consumption, overall (14.94%) and specifically derived from beverages (15.21%) and foods (14.26%) were observed. Total fluid intake at the third 24-hour recall was inversely associated with the 2-month change in body weight (r = -.24, p < .02). Long-term (6-month & 12 month) BMI status was inversely associated with beverage intake especially at the 3rd 24-hour recall (r = .38, p < .01). Increased water intake derived from food, in turn, was associated with increases in several micronutrients important in chronic disease prevention, such as vitamin C, vitamin A, carotenoids and potassium. Increased water intake derived from beverages, on the other hand, was associated with increased intake only of phosphorus, protein and alcohol.

Conclusion: Fluid intake mediates impact of physical activity on nutrient intake and may facilitate desirable body weight changes. Increased fluid derived from food is associated with increased intake of healthful micronutrients.