Objective: To compare the most commonly used equations to predict body fatness from skinfold thickness, in male and female adolescents, with dual-energy X-ray absorptiometry (DXA) as a reference method of fatness measurement. Design: Cross-sectional nutrition survey. Setting: General adolescent population from Zaragoza (Spain). Subjects and methods: A total of 238 Caucasian adolescents (167 females and 113 males), aged 13.0-17.9 y, were recruited from 15 school groups in 11 public and private schools. The percentage fat mass (%FM) was calculated by using skinfoldthickness equations. Predicted %FM was compared with the reference %FM values, measured by DXA. The lack of agreement between methods was assessed by calculating the bias and its 95% limits of agreement.Results: Most equations did not demonstrate good agreement compared with DXA. However, in male adolescents, Slaughter et al equations showed relative biases that were not dependent on body fatness and the limits of agreement were narrower than those obtained from the rest of equations. In females, Brook's equation showed nonsignificant differences against DXA and the narrowest 95% limits of agreement. Only biases from Brook and Slaughter et al equations were not dependent on body fatness in female adolescents. Conclusions: Accuracy of most of the skinfold-thickness equations for assessment of %FM in adolescents was poor at the individual level. Nevertheless, to predict %FM when a relative index of fatness is required in field or clinical studies, Slaughter et al equations may be used in adolescents from both sexes and the Brook equation in female adolescents. Sponsorship: Instituto de Salud Carlos III, Spain.

Results from longitudinal studies must be taken into account in order to design preventive strategies to counteract the increased prevalence of obesity and its consequences in children. Lack of breastfeeding, high early energy intake and high intake of sugar-sweetened beverages seem to be the main dietary factors contributing to obesity development.

Lifestyle plays an important role in the development of obesity during childhood and adolescence. We provide up-to-date information about the relationship between obesity and food intake and dietary patterns in adolescents. Scientific evidence is increasing about the dietary factors associated with this relationship, specifically a low meal frequency, skipping breakfast, and a high consumption of sugar sweetened beverages. Maybe some of the reviewed dietary factors could cluster in the same population of adolescents, increasing the individual risk. There is little information about dietary patterns and current time trends in adolescents; however, the available data seem to show that the tendency in the adolescent population worldwide is to increase those dietary factors related with obesity development. Public health efforts should be emphasized in order to decrease the current tendency. Regular family meals could serve as role models for healthy eating behaviors. Educational intervention programs for parents, aiming to modify the healthfulness of the diet, seems to be one of the most adequate tools to deal with the worldwide obesity epidemic.

Waist circumference seems to be the best predictor of children with the metabolic syndrome in paediatric clinical settings.