Modified fat diets: do they apply to infancy?

Almost no data exist to permit assessment of the optimal fat content in the diet of the 6- to 12-month-old infant. Human milk contains about 50% of energy as fat, a large portion of it saturated fat. Commercial infant formulas mimic this proportion but use vegetable sources; most of them also duplicate the saturated fat fraction. At present, only linoleic acid is known to be an essential fatty acid. However, if all but 2% to 3% of energy had to come from sources other than fat, the energy density of the feed would be low, perhaps too low to permit ingestion of adequate energy. On the other hand, if fat concentration were increased at the expense of carbohydrates, ketosis would result.