Low-Fat Diet Not Good for Kids

August 16, 2007

GREENVILLE, N.C. -- Children need fat to fuel growth and should not be put on low-fat diets, researchers said.

GREENVILLE, N.C., Aug. 16 -- Children need fat to fuel growth and should not be put on low-fat diets, researchers said.

Children burn more fat per kilocalorie of energy expended than adults even at a low activity level (P

All were healthy, of normal weight, and had a normal activity level without a rigorous physical training program.

A consistent metabolic background was established for three days with a weight maintenance diet provided for participants as "take out." Then, each individual had metabolic rate measured over nine hours using a hood system or room calorimeter while they watched movies, read, or played games. Measurement was repeated on two separate occasions.

The researchers found that daily calorie expenditure during testing was as expected given the lack of physical activity: 2,072 kcal for men, 1,496 kcal for boys, 1,329 kcal for women, and 1,194 kcal for girls.

However, energy expenditure normalized to lean body mass was significantly higher for children than adults (50.4 kcal/d/kg for boys, 52.4 for girls, 29.7 for men, and 29.48 for women, P

"Prepubescent children may oxidize more fat relative to total energy expenditure than adults for the purpose of supporting normal growth processes such as higher rates of protein synthesis, lipid storage and bone growth," they wrote.

They dismissed the possibility that their findings could be chalked up to heightened fear or arousal among children during tests.

"While not quantified, our subjective impression was that children were comfortable in the room calorimeter in a manner similar to the adults," the investigators wrote.

Nonetheless, the generalizability of the findings was limited by the small sample size, and larger studies would be needed to verify the results, they noted.

"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," they concluded.