How is metabolism affected by a low-carbohydrate diet compared to a low-fat diet?
One possible explanation for reduced body weight with the low-carbohydrate diet might be an activated fatty acid oxidation. After 2 weeks on a low-carbohydrate diet (30% carbohydrate by energy, 55% fat and 15% protein) total fatty acid oxidation was found to be significantly elevated, 4.60.5 mol/kg/min, compared to a low-fat diet (carbohydrate 75%, fat 10% and protein 15%), being 2.40.7 mol/kg/min, in healthy men.9 Not only fat oxidation is affected by the low-carbohydrate diets, but also the carbohydrate metabolism. The rate of gluconeogenesis was found to be significantly elevated in prepubertal children eating a low-carbohydrate diet (30% carbohydrate, 55% fat and 15% protein) compared to children eating a low-fat diet (60% carbohydrate, 25% fat and 15% protein) for 7 days. This difference was not observed in adult subjects. Hence, children easily adapt to extreme changes in fat and carbohydrate content of the diet by adaptation of metabolism. In the children there was no change in
