ExtractIt seemed desirable and interesting to study the total energy expended during a period of several hours under conditions most commonly encountered under different infant care practices.The investigations were carried out on a total of 23 premature infants with a birth weight ranging from 1100 to 2120 g and aged from 2 to 31 days. Oxygen consumption was measured by an open circuit method using the Kipp diaferometer. Using three thermal conditions, measurements were started when four hours had elapsed after the last feed. Physical activity was observed and recorded continuously by an arbitrary method. The basal metabolic rate and the metabolic response to cold subtracted from the total metabolism measured under different experimental conditions gave the combined number of calories produced by specific dynamic action and physical activity. The information obtained from a previous study on specific dynamic action made it possible to approximate the calorigenic effect of food in the four series of examinations reported.Details of the studies carried out on premature infants while receiving human milk and kept in incubators with temperature maintained between 33-36° are shown in table I. In addition to the basal metabolic rate, total heat production observed throughout the observational period, calculated total daily heat production, and the percentage distribution of times spent in sleep and in physical activity with various intensity are also listed.. The average total heat production observed exceeds the minimal metabolic rate by 9.8 kcal/kg/24 h per subject. If allowance is made for the specific dynamic action expected from the average daily intake of human milk (1.1 g protein/ml) 3.0 kcal/kg/24 h can be attributed to muscular activity. The magnitude of this component of the total energy expenditure is consistent with the markedly reduced physical activity exhibited by premature infants maintained in a thermally neutral environment.The results obtained on premature infants receiving an artificial formula containing 3.43 % protein are listed in table II and shown diagrammatically in figure 1. The total daily caloric output averages 55.0 kcal/kg/24 h, a value roughly 39% above the basal rate, in contrast to the average increase of 25 % observed in breast milk-fed infants. This difference in the combined quota of specific dynamic action and physical activity (8.8 and 15.3 kcal/kg/24 h, respectively) is due partly to the higher protein and caloric intake, and partly to the lesser proportion of time spent in deep sleep. Table III summarizes the results of studies of the energy exchange of five swaddled premature infants kept at a room temperature of 20-22°. It can be seen that the total daily heat production averages 58.3 kcal/kg/24 h, which is not appreciably greater than that observed in Adapta-fed infants maintained at neutral temperature. The extra calories above the basal amount to 18.6 kcal/kg/24 h, II Pediat. Res., Vol. 2, No. 3 (1968) 162 MESTYAN, JARAI, FEKETE representing a 47 % rise above the minim...

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In 11 obese children aged 12.5 (+/- 0.7) years with normal glucose tolerance and 7 lean, control children aged 11.9 +/- 0.7 years the preload resting energy expenditure and thermogenic response to a standardised meal was measured by indirect calorimetry. Preload energy expenditure was higher in obese children when expressed in absolute terms than in controls, but was not different when corrected for lean body weight. Four children with obesity of recent onset had lower food-induced thermogenesis and insulin response then seven overweight children with long-standing obesity. Food-induced thermogenesis and insulin response showed a significant positive correlation. It is concluded that food-induced thermogenesis is reduced in the early phase of childhood obesity but increased in the later phase when hyperinsulinaemia develops, pointing towards an important role of insulin in food-induced thermogenesis.