Is Nutrient Adequacy Linked to Physical Activity Level in Healthy Young Adults?

Abstract

Both physical activity (PA) and diet are important contributors to health and well-being but there is limited information on the interaction of these behaviors and whether the association differs by weight category. PURPOSE: To evaluate the association between physical activity (PA) and dietary intake in young, normal weight and overweight/obese adults. METHODS: The cross-sectional analysis includes 412 adults (27.6±3.8 years, 48% male) with valid dietary and PA data. Height (cm) and weight (kg) were measured with participants in surgical scrubs and bare feet. BMI was calculated (kg/m2) and used to differentiate between normal weight (BMI<25) and overweight/obese (BMI≥25). Multiple 24-hr dietary recalls (24HR) were administered over a period of 14 days and nutrient intake was calculated as the average of at least two 24HR. Total daily energy expenditure (TDEE) was assessed over a period of 10 days with the BodyMedia armband during the time period diet recalls were administered. Resting metabolic rate (RMR) was measured via indirect calorimetry after a 12 hour overnight fast and at least 24 hours abstention from exercise. Physical activity level (PAL=TDEE/RMR) was calculated and used to stratify groups (PAL 1<1.60, 1.6≤PAL 2<1.9, PAL 3≥1.9). RESULTS: A majority of participants (>60%) met macronutrient recommendations (% of calories/day). Conformance with micronutrient recommendations varied between 3% and 99%. Macronutrient intake did not differ between activity groups but a higher PAL was associated with higher fiber intake. In normal weight participants, higher PAL was associated with the higher intakes of minerals (except calcium, iron, and zinc), thiamin, riboflavin, niacin, vitamin B12, and choline (p for trend <0.05). In the overweight/obese group, higher PAL was associated with the higher intakes of potassium, sodium, copper, and niacin (p for trend <0.05). CONCLUSIONS: Higher PA is associated with increased fiber and micronutrient intake in normal weight and overweight/obese young adults. An active lifestyle, therefore, may provide additional benefits beyond those directly attributed to PA.