Substances used by food manufacturers to replace fat in various food products, providing the overall sensation of dietary fat (such as “mouth feel”) without being metabolized as fat by the body. There are three basic types of fat replacers: carbohydrate-based, protein-based, and fat-based.
Carbohydrate-based fat replacers include cellulose, maltodextrins, gums, starches, fiber, and polydextrose. They are used in many foods, including cheeses, salad dressings, processed meat, and sweets. According to some diet experts, people with diabetes should use carbohydrate-based fat replacers cautiously, since they may raise blood glucose levels.
Protein-based fat replacers are modified proteins from sources such as egg white and whey. One common form is the product Simplesse. While they are not suitable for frying, they can be used in many heated foods, such as cream soups, pasteurized products, and baked goods.
Fat-based fat replacers contain fatty acids that have been modified to provide fewer or no calories. Some fat replacers, such as olestra (Olean), pass through the body unabsorbed and provide zero calories. Salatrim (Benefat), a newer product, is only partially absorbed and provides only five calories per gram (ordinary fats provide nine calories per gram). The advantages of fat-based fat replacers are their ability to withstand heat and their general versatility. They are commonly used in chocolate, confections, baked goods, and savory snacks.
Though they are both used in products currently on the market, the safety of olestra and salatrim has been questioned by certain scientists and public interest groups, most notably the Center for Science in the Public Interest (CSPI). According to CSPI, studies show that these fat replacers may cause intestinal cramps and loose stools in some people. Clinical studies have also shown that olestra reduces the absorption of fat-soluble nutrients, including the vitamins A, D, E, K, and carotenoids, from foods eaten at the same time as olestra. In response to this problem, foods that contain olestra are fortified with extra amounts of these vitamins.
Studies are inconclusive as to whether fat replacers can help people lose weight. Some studies have suggested that people consuming foods containing fat replacers overcompensate for the missing fat calories by eating more. If you plan to use foods made with fat replacers, be sure to read the Nutrition Facts panel on their labels and fit them into your meal plan accordingly. A calorie is still a calorie, no matter where it comes from.