The American Academy of Pediatrics recommended allowance for essential fatty acids is 3 percent of total dietary calories for infants and, according to the Food and Nutrition Board of the National Academy of Sciences, 2 percent, in the form of linoleic acid, for adults.
Vegetable sources, especially vegetable oils, contribute the largest quantities of linoleic acid as well as arachidonic and linolenic acids, the other two primary fatty acids.
All fats, no matter what their source, have the same caloric value, but whether you eat more saturated or polyunsaturated fats may make a difference in your blood cholesterol. A number of nutrition experts recommend a reduction of saturated fats and an increase in polyunsaturated fats in the diet.