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.

BACKGROUND: Obese women often give birth to large-for-gestational age infants (typically defined as a birth weight greater than the 90th percentile), who are at risk of birth injuries and of developing metabolic syndrome later in life. The mechanisms underlying increased fetal growth remain to be established. OBJECTIVE: We aimed to identify maternal hormones that can explain the link between dietary intake, body mass index (BMI), and birth weight. DESIGN: Pregnant women with BMIs (in kg/m(2)) ranging from 17 to 44 (n = 49) were recruited in gestational weeks 8-12. Serum hormone concentrations were measured and dietary history interviews were performed in the first and third trimesters. Multiple regression models were produced to identify hormones that correlate with birth weight and are influenced by BMI or dietary factors. RESULTS: We found a strong positive correlation between BMI and first- and third-trimester insulin and leptin concentrations and a negative correlation between BMI and first-trimester adiponectin and first- and third-trimester insulin-like growth factor binding protein-1 (IGFBP-1). Maternal total fat intake in the first trimester was positively correlated with maternal leptin and inversely correlated with adiponectin. In addition, third-trimester total fat intake was positively correlated with circulating resistin concentrations. First-trimester maternal serum resistin was positively correlated with birth weight, whereas third-trimester maternal IGFBP-1 was negatively correlated with birth weight. CONCLUSIONS: High first-trimester maternal serum resistin and low third-trimester IGFBP-1 were correlated with increased birth weight. We propose that low serum concentrations of IGFBP-1 represent a link between high BMI and increased fetal growth by increasing the bioavailability of insulin-like growth factor-I, which up-regulates placental nutrient transport.

In 91 healthy term infants breast-milk intake was measured at 2, 4, and 9 mo by test weighing and human milk macronutrient content by infrared analysis every 2-4 wk. In infants exclusively breast-fed, mean milk intake was 781 and 855 mL/24 h at 2 and 4 mo, respectively, and correlated positively with the current weight of the infant and negatively with the amount of formula supplement given at the maternity ward. Median daily energy intake was considerably below current recommendations (423 and 381 kJ/kg body wt at 2 and 4 mo, respectively). Protein concentration in the milk was approximately 8% higher in primipara. Median daily protein intake was 1.3 and 1.0 g/kg body wt at 2 and 4 mo, respectively. Median fat concentration was 39.2 g/L and was positively associated with pregnancy weight gain. This supports the hypothesis that maternal fat stores laid down during pregnancy are easier to mobilize during lactation than are other fat stores and, if low, may limit milk fat when exhausted.