Reproducibility of short-term food intake and subjective appetite scores after a glucose preload, ventilation threshold, and body composition in boys

The objective of these studies was to assess the reproducibility of (i) short-term food intake (FI) and subjective appetite following a glucose preload, (ii) ventilation threshold (VT) and subjective appetite after short-duration exercise, and (iii) body composition assessed by bioelectrical impedance (BIA). On two separate weekend mornings, boys (n = 11; aged 9-14 years) received drinks containing 50 g glucose made up to 250 mL with water 2 h after a standardized breakfast. FI from a pizza meal was measured 30 min later. Subjective appetite was measured before and after the glucose loads and the VT measures. VTs were measured on 2 weekday evenings, 1 week apart. BIA was measured during the FI assessment sessions. Short-term FI after the glucose preload was highly reproducible. Mean energy intake was 925 +/- 139 kcal on the first day and 988 +/- 147 kcal on the second day (coefficient of repeatability (CR) = 259 kcal; intra-class correlation coefficient (ICC) = 0.96). Moderate reproducibility of the average appetite score was found at 30 min (CR = 24 mm; ICC = 0.82). Subjective appetite was increased similarly by short-duration exercise on both days (CR = 19 mm). Absolute VT was more highly reproducible (CR = 359 mL O2.min(-1), ICC = 0.85) than VT expressed on the basis of body weight (CR = 8.0 mL O2.kg(-1).min(-1), ICC = 0.59). Fat mass (FM) estimated from BIA was highly reproducible (CR = 2.7 kg, ICC = 0.95), but underestimated FM compared with skinfolds. In conclusion, FI and subjective appetite scores in response to glucose preloads, VT, subjective appetite after short-duration exercise, and estimates of FM from BIA are reproducible in boys.