Of all the nutrients ingested, fat is the most difficult for the body to absorb. There are a number of physicochemical changes that a droplet of fat must undergo before it is absorbed and enters the bloodstream. This article will describe these changes and show where in various disease states normal physiology is altered.
On the average, 140 g of fat is eaten daily by American adults. This composes 42% of their caloric intake. Ninety-five percent of this fat is in the form of triglycerides, preponderantly containing the saturated palmitic and stearic fatty acids and the unsaturated oleic and linoleic fatty acids. During the past 25 years, there has been a gradual shift away from lard and butter in the diet to margarine and vegetable oils, substantially increasing the percentage of unsaturated fats in the diet. Saturated fatty acids now compose 37% of the per capita total fat consumption, while