Fat substitutes are compounds made from carbohydrates, protein, fat or some combination. They are used in foods in place of fat. These substances are intended to have the same appearance, taste and texture as fat and help give foods the same characteristics they would have if prepared with fat.

Fat substitutes are designed to provide all of fat’s positive attributes while minimizing the health risks traditionally associated with certain types of fat. These substances contain less available energy (calories) than natural fat and typically are lower in saturated fat and cholesterol.

There are three major types of fat substitutes. Typically, a combination of these fat substitutes is necessary to achieve the same effect in a food as a single fat. The three types of fat substitutes are:

• Carbohydrate-based substitutes. Made with plant polysaccharides in place of fat. The carbohydrate ingredients absorb water and take on a thickness and creaminess that is similar to fat.
  
  
• Protein-based fat substitutes. Made with protein from egg whites, fat-free milk or whey protein. They provide a creamy sensation, improve appearance and texture and stabilize emulsions in sauces, spreads and salad dressings.
  
  
• Fat-based substitutes. Made with fats that are altered chemically, they provide few calories to the body because the body cannot absorb the fatty acids. Olestra is a well known example of a fat-based substitute used in snack foods and frying.

Fat substitutes can be found in low-fat or fat-free versions of foods that normally contain fats. Such products include baked foods, candy, cheese, cookies, ice cream, margarine, mayonnaise, salad dressing and sour cream.

People generally use fat substitutes as a way to lower their overall fat intake in order to lose weight, or to improve general health. However, fat substitutes should not be consumed excessively. These products still contain calories and fat and should be eaten in moderation. In addition, there are some concerns about the effect fat substitutes may have. For instance, olestra is known to cause stomach cramping and discomfort in some people. The long-term benefits and concerns are not yet known.