Does fat intake predict adiposity in healthy children and adolescents aged 2-15y? A longitudinal analysis

Objective: To investigate the relationship between food energy and macronutrient intake and body fatness assessed up to seven times between 2 and 15 y of age. Design: Prospective, observational study. Generalised linear estimating equations were used to evaluate the longitudinal relationship between body fatness and macronutrient intake. Regression analysis was used to assess whether body fatness at a particular age was predicted by intake at any of the previous ages. Setting: Community-based project in Adelaide, South Australia. Subjects: In all 143-243 subjects from a representative birth cohort of healthy children recruited in 1975 and followed over 15 y. Main outcome measures: The dependent variables were body mass index (BMI), triceps (TC) and subscapular (SS) skinfolds, expressed as standard deviation (s.d.) scores at each age. The predictor variables were energy-adjusted macronutrient intake and total energy intake, estimated from a 3-4 day diet diary, the previous corresponding measure of body fatness, sex and parental BMT, TC or SS. Results: Across 2-15 y energy-adjusted fat and carbohydrate intakes were respectively directly and inversely related to SS skinfold measures but not to either BMI or TC skinfold. The best predictor of fatness was previous adiposity, with the effect strengthening as the age interval shortened. Parental BMI, maternal SS and paternal TC contributed to the variance of the corresponding measure in children at some but not all ages. Conclusions: The current level of body fatness of the child and parental adiposity are more important predictors than dietary intake variables of risk of children becoming or remaining overweight as they grow.