Energy density of the diet and change in body fatness from childhood to adolescence; is there a relation?
McCaffrey TA., Rennie KL., Kerr MA., Wallace JM., Hannon-Fletcher MP., Coward WA., Jebb SA., Livingstone MB.
BACKGROUND: The contribution of energy density (ED) of the total diet to increased risk of obesity from childhood into adolescence is unclear. OBJECTIVE: We assessed the relation between the ED of the diet in childhood, calculated in a number of ways, and change in adiposity from childhood to adolescence. DESIGN: In a prospective study, 48 children (30 boys, 18 girls) were initially studied at age 6-8 y (baseline) and followed up at age 13-17 y. Daily ED, energy intake, and food intake were assessed at baseline by 7-d weighed food records concurrent with estimates of total energy expenditure (TEE) by doubly labeled water. ED was calculated with the use of 5 published methods. Obesity risk was defined with the use of body fat from total body water by isotope dilution. Body fat was normalized for height and expressed as fat mass index (FMI). Change in adiposity was calculated as follow-up FMI minus baseline FMI. RESULTS: Misreporting of energy intake at the group level at baseline was low relative to the TEE. ED of the total diet at baseline by the 3 methods for calculating ED that excluded all or most beverages was prospectively associated with change in FMI. However, ED of the total diet by any of the methods was not associated with change in the percentage body fat, body mass index, or waist circumference z scores. CONCLUSION: The methods used to calculate ED and to assess obesity risk lead to different conclusions about the relation between the ED of the diet in childhood and gain in fat into adolescence.