Influence of changes in sedentary behavior on energy and macronutrient intake in youth

Background: Changes in sedentary behavior may be related to changes in energy intake. Objective: The purpose of this study was to investigate how experimental changes in the amount of sedentary behaviors influence energy intake. Design: Sixteen nonoverweight 12-16-y-old youth were studied in a within-subject crossover design with three 3-wk phases: baseline, increasing targeted sedentary behaviors by 25-50% (increase phase), and decreasing targeted sedentary behaviors by 25-50% (decrease phase). Repeated 24-h recalls were used to assess energy and macronutrient intakes during targeted sedentary behaviors. Accelerometers were used to assess activity levels. Results: Targeted sedentary behaviors increased by 81.5 min/d (45.8%) and decreased by 109.8 min/d (-61.2%) from baseline (both: P < 0.01). Girls increased sedentary behaviors significantly more than did boys (107.3 and 55.8 min/d, respectively; P < 0.01) in the increase phase. Energy intake decreased (-463.0 kcal/d; P < 0.01) when sedentary behaviors decreased: the decrease in fat intake was -295.2 kcal/d (P < 0.01). No significant changes in energy intake were observed when sedentary behaviors were increased. Youth also increased their activity by 102.4 activity counts · min^-1 · d^-1 (estimated at 113.1 kcal) when sedentary behaviors were decreased (P < 0.05). Conclusions: Decreasing sedentary behaviors can decrease energy intake in nonoverweight adolescent youth and should be considered an important component of interventions to prevent obesity and to regulate body weight.