Although fat is no longer the dirty word for consumers that it was just five years ago, there is still plenty of interest in eating lower fat foods. There are more than 5,000 reduced fat food products available, with the most popular being fat-free or low-fat milk products and salad dressings. But processed foods can contain a variety of fat replacers made from starch, protein, or fat.
Most fat substitutes are chosen for specific functions like retaining moisture or modifying the texture and mouth feel of foods to make up for lower fat content. Things like pectin or guar gum are dietary fiber; olestra is an artificial fat that is not absorbed. Monoglycerides and diglycerides are simply chopped off parts of vegetable oils that are emulsified with water. These latter compounds have the same calories as fat but reduce the amount of fat needed. In
fact, they are fat but are usually added in small enough amounts that they don't show up on the nutrition facts label, only on the ingredients list.
The American Heart Association recommends most fat substitutes without hesitation. They have some reservations about olestra because it reduces the levels of some carotenoids in the
blood. AHA recommends "judicious" use of fat substitutes within the context of a healthy diet.