Total energy expenditure and physical activity as assessed by the doubly labeled water method in Swedish adolescents in whom energy intake was underestimated by 7-d diet records.

Swedish children and adolescents may be adopting a sedentary lifestyle with low energy expenditures and intakes, but no quantitative data are available. The purpose of the present study in 50 adolescents aged 15 y was to investigate whether assessment of total energy expenditure (TEE) and physical activity level (PAL) by the doubly labeled water method and indirect calorimetry and estimation of energy intake by a 7-d diet record would indicate physical inactivity. The boys' (n = 25) mean weight was 112% and the girls' (n = 25) was 109% of Swedish reference values from 1976; the mean height of both boys and girls was 102% of those reference values. Mean TEE in the boys and girls, 13.82 +/- 1.90 and 10.70 +/- 1.59 MJ/d, and mean PAL (TEE/basal metabolic rate), 1.89 +/- 0.16 and 1.79 +/- 0.22, respectively, were nonsignificantly higher than corresponding figures from other published studies. Mean energy intake as a percentage of TEE was 81.9 +/- 17.9% in the boys and 78.3 +/- 16.4% in the girls. Significant negative correlations were found both between energy intake as a percentage of TEE and percentage body fat and between energy intake as a percentage of TEE and body mass index. These results add to the evidence that 7-d diet records underestimate energy intake in adolescents, particularly those with a tendency for overweight and increased body fat. The results support indications of a trend of increasing body weight and height in Swedish adolescents, but conflict with the presumptions of low physical activity, low energy expenditure, and low energy intake. These results support the view that current recommendations for energy intake during adolescence are too low.