Food and Behaviour Research

Donate Log In

Relative fat oxidation is higher in children than adults

John C Kostyak, Penny Kris-Etherton, Deborah Bagshaw, James P DeLany, Peter A Farrell (2007) Nutrition Journal 6 19 

Web URL: View this and related abstracts via PubMed here. Free full text of this article is available online


Prepubescent children may oxidize fatty acids more readily than adults. Therefore, dietary fat needs would be higher for children compared with adults. The dietary fat recommendations are higher for children 4 to 18 yrs (i.e., 25 to 35% of energy) compared with adults (i.e., 20 to 35% of energy). Despite this, many parents and children restrict dietary fat for health reasons.

METHODS: This study assessed whether rates of fat oxidation are similar between prepubescent children and adults. Ten children (8.71.4yr, 3313 kg meanSD) in Tanner stage 1 and 10 adults (41.68 yr, 74 13 kg) were fed a weight maintenance diet for three days to maintain body weight and to establish a consistent background for metabolic rate measurements (all foods provided). Metabolic rate was measured on three separate occasions before and immediately after breakfast and for 9 hrs using a hood system (twice) or a room calorimeter where continuous metabolic measurements were taken.

RESULTS: During all three sessions whole body fat oxidation was higher in children (lower RQ) compared to adults (mean RQ= 0.84 .016 for children and 0.87.02, for adults, p<0.02). Although, total grams of fat oxidized was similar in children (62.7 20 g /24 hrs) compared to adults (51.4 19 g /24 hrs), the grams of fat oxidized relative to calorie expenditure was higher in children (0.047 .01 g/kcal, compared to adults (0.032 .01 p<0.02). Females oxidized more fat relative to calorie expenditure than males of a similar age. A factor way ANOVA showed no interaction between gender and age in terms of fax oxidation.

CONCLUSIONS: These data suggest that fat oxidation relative to total calorie expenditure is higher in prepubescent children than in adults. Consistent with current dietary guidelines, a moderate fat diet is appropriate for children within the context of a diet that meets their energy and nutrient needs.


The finding that children 'burn off' fats faster than adults and that children therefore require at least a moderate-fat diet to meet their energy and nutrient needs is perhaps not surprising, although generalisation from these results is limited by the fact that only ten adults and ten children were studied.

These findings illustrate why 'low-fat' diets are not suitable for growing children, unless recommended and supervised by an appropriately qualified professional (such as a dietitian). A balanced diet with sufficient quantities of the right kinds of fats is necessary for a child's healthy growth and development - and parents and health professionals would do far better to focus on the QUALITY, not the quantity of fats consumed.

For an accessible summary of this research, see the associated news article: