Objectives: To measure total energy expenditure (TEE) and total body water (TBW) in healthy Swedish children 9 or 14 months of age. To compare their TEE with current recommendations for energy intake. To define their body composition and relate this to energy expenditure.
Design: : Children were investigated at 9 or 14 months. The following variables were measured: TEE and TBW (by the doubly labelled water method), weight and length. Total body fat (TBF), sleeping metabolic rate, activity energy expenditure and physical activity level (PAL) were calculated.
Subjects: Thirty infants 9 months of age and 29 children 14 months of age.
Results: : TEE was 323+/-38, 322+/-29, 313+/-23 and 331+/-28 kJ/kg/day in 9-month-old girls, 9-month-old boys, 14-month-old girls and 14-month-old boys, respectively. At 9 months of age girls and boys contained 29.6+/-4.8 and 29.7+/-4.5% TBF, respectively. At 14 months the corresponding figures were 29.1+/-4.3 and 28.2+/-4.3%. There was a significant negative relationship between PAL and %TBF (r=-0.81, P<0.001, n=59).
Conclusions: Measured TEE plus calculated energy cost of growth confirm previous estimates that the physiological energy requirements of children 9 and 14 months of age are 15-20% lower than current recommendations for energy intake. One possible interpretation of the relationship between PAL and %TBF is that children with a high TBF content are less physically active than children with less TBF. However, this relationship needs further studies.