The effects of moderate exercise training on nutrient intake in mildly obese women

The relationship between moderate exercise training (five 45-minute sessions per week, brisk walking at 62 +/- 2% VO2 max for 15 weeks) and changes in nutrient intake was investigated in a group of 36 sedentary, mildly obese women. The study was conducted using a 2 x 3 factorial design (two groups of subjects: exercise and nonexercise groups; three periods: baseline, 6-week, and 15-week testing sessions). Data were analyzed using repeated measures ANOVA. The pattern of change in caloric intake over time tended to be different between groups (F[2, 68] = 2.50, p = .089); the exercise group experienced a significant decrease in caloric intake by 15 weeks. Significant group x time interactions were found for intakes of carbohydrate, dietary fiber, thiamin, niacin, vitamin B-6, and folate. Intake tended to decrease in the exercise group and to increase in the nonexercise group. Change in intake of each of these nutrients was significantly correlated with change in bread and cereal consumption. The pattern of change in bread and cereal intake over time was significantly different between groups (Pillais Trace = 0.266, F[2, 33] = 5.99, p = .006); the exercise group had significant decreases in intake at 6 and 15 weeks vs baseline values. These data suggest that mildly obese women reduce energy intake subsequent to initiating an exercise program; concomitantly there is a decrease in the quality of nutrient intake from their diets compared with those of sedentary controls.