Food-induced thermogenesis in obese children.

In 11 obese children aged 12.5 (+/- 0.7) years with normal glucose tolerance and 7 lean, control children aged 11.9 +/- 0.7 years the preload resting energy expenditure and thermogenic response to a standardised meal was measured by indirect calorimetry. Preload energy expenditure was higher in obese children when expressed in absolute terms than in controls, but was not different when corrected for lean body weight. Four children with obesity of recent onset had lower food-induced thermogenesis and insulin response then seven overweight children with long-standing obesity. Food-induced thermogenesis and insulin response showed a significant positive correlation. It is concluded that food-induced thermogenesis is reduced in the early phase of childhood obesity but increased in the later phase when hyperinsulinaemia develops, pointing towards an important role of insulin in food-induced thermogenesis.