Influence of environmental factors on meal intake in overweight and normal-weight male adolescents. A laboratory study.

OBJECTIVE: To investigate the influence of environmental conditions on energy intake at lunch time in normal-weight versus overweight male adolescents.
DESIGN: Healthy 15-17 year-old adolescents (19 normal-weight, 19 overweight) participated in lunch tests under laboratory settings. Four conditions were compared: eating in groups, eating alone, eating alone while viewing television, eating alone while listening to music. The same menus (two solid foods, three drinks) were offered ad libitum.
RESULTS: Significant group differences between meal conditions were observed for energy intake from solid foods, but not from drinks: normal-weight participants ate more solids while listening to music (5731±426 kJ) than when eating alone (5012±364 kJ, P=0.026) or in groups (4974±272 kJ, P=0.049), whereas overweight participants ate more solid foods while viewing television (5806±330 kJ) than when eating in groups (5208±201 kJ, P=0.014) or while listening to music (5288±255 kJ, P=0.035). On average, total energy intake at lunch (solids plus liquids) was found to be increased only in the overweight when viewing television (8527±535 kJ) compared to eating in group (7348±445 kJ, P=0.037) or while listening to music (7532±435 kJ, P=0.049).
CONCLUSION: Environmental conditions modulate total energy intake at lunch in adolescents and susceptibility to external factors can be affected by weight status. Whether such effects can in turn affect energy balance and weight status remains to be investigated.