Fat intake and adiposity in 8 to 11-year-old obese children.

OBJECTIVE

To investigate the relationships between diet composition, body composition, and macronutrient oxidation at rest in obese and non-obese children.

DESIGN

Cross-sectional study on fat intake, adiposity and postabsorptive macronutrients oxidation rates.

SUBJECTS

82 prepubertal (age: 9.1 +/- 1.1 y) children, 30 obese (FM = 32.6 +/- 6.1%) and 52 non-obese (FM = 15.6 +/- 5.1%).

MEASUREMENTS

Subcutaneous skinfold thickness for body composition, diet history for energy and nutrient intake, indirect calorimetry for resting metabolic rate (RMR) and RQ measurement.

RESULTS

Energy intake (EI) was comparable in obese and non-obese children. Adjusted for RMR by ANCOVA, using RMR as the covariate, EI was significantly lower in obese than in non-obese children indicating either a blunted physical activity or a systematic underestimation of EI. Protein and carbohydrate intakes expressed as a percentage of total energy intake (%EI) were not significantly different in the two groups. Lipid intake (%EI) was slightly but significantly higher in the obese than in the non-obese group either unadjusted or adjusted for RMR by ANCOVA. The postabsorptive RQ was significantly lower in obese than in non-obese children. In the total group, %FM was weakly but significantly correlated to lipid intake (%EI).

CONCLUSION

Obese prepubertal children have a higher relative fat intake than non-obese children and their FM is associated with this factor. The lower postabsorptive RQ of obese children may indicate a compensatory mechanism to achieve fat equilibrium by enhanced fat oxidation.