Definition :
Fat replacers, also called fat substitutes, are substances that take the place of all or some of the fat in a food and yet give the food a taste, texture, and mouth feel similar to the original full-fat food.
Purpose :
Fat replacers serve two purposes. They reduce the amount of fat in food, and they usually reduce the calorie content of the food.
Description :
Fat is not a single substance, but a collection of different compounds that are all made of a glycerol molecule and three varying fatty acids. Fat is a necessary part of a healthy diet. It provides essential fatty acids, helps regulate cholesterol metabolism, carries fat-soluble vitamins and carotenoids throughout the body, contains the building blocks for prostaglandins, and provides nine calories of energy per gram.
Although there is no official recommended daily allowance (RDA) for fat, the American Heart Association strongly recommends that fats provide no more than 30% of one’s total daily calories. The average American gets about 34% of his or her calories from fat (down from about 41% in the 1950s).
As of 2000, there were more than 5,000 reduced fat foods on the market. New reduced- and low-fat foods were being introduced at the rate of about 1,000 per year. Concern about heart disease, obesity, diabetes, and their relationship to diet has turned processed foods containing fat replacers into a multi-billion dollar industry.
To be labeled ‘‘low fat’’ a product must contain 3 g of fat or less per serving. To be labeled ‘‘reduced fat’’ or ‘‘reduced calorie,’’ a product must contain 25% less fat or 25% fewer calories than the regular version of the product. ‘‘Light’’ foods contain half the fat or onethird the calories of the regular product. ‘‘Fat-free’’ means the food has less than 0.5 g of fat per serving. Fat enhances food flavor, adds volume, and gives food a particular texture and mouth feel. Removing fat from food usually results in unappealing, unmarketable products. To achieve fat and calorie reduction, processors have turned to fat replacers.
Types of fat replacers
Fat replacers are either carbohydrate-based, proteinbased, or fat-based. Most foods use several different fat replacers that come from different sources. Many are substances that have been found in foods for years, but are now being used in different ways.
Carbohydrate-based fat substitutes include guar gum, polydextrose (Litess), gum Arabic, xanthum gum, carrageenan (an extract from seaweed), dried plum paste, modified food starches, oat fiber, and wheat fiber. Carbohydrate-based fat replacers have the creaminess of fat. They absorb water, add volume, thicken, and stabilize foods. They are used in baked goods, frozen desserts, yogurts, cheeses, sour cream, low-fat puddings, processed meats, salad dressings, sauces, and spreads. Because fat contains nine calories per gram and carbohydrates contain only four calories per gram, every gram of fat replaced with a gram of a carbohydrate-based fat substitute reduces the calorie content of the food by five calories as well as reducing the fat content. Carbohydrate-based fat replacers cannot be used in frying.
Protein-based fat replacers (e.g., Simplesse) are made from milk protein and/or egg white protein. These proteins are heated and then whirled violently in blenders to produce very tiny particles in a process called microparticulation. These microparticles give protein-based fat replacers the same mouth feel as fats. Like carbohydrate-based substitutes, protein provides four calories per gram so they reduce the calorie content of food by five calories per gram of fat replaced. Protein-based fat replacers are used in butter, cheese, frozen dairy desserts, mayonnaise, soups, salad dressings, and sour cream. They do not work well in baked goods and cannot be used for frying.
Fat-based fat replacers (e.g., Caprenin, Benefat, Olean) are made of fat molecules that are modified so that they cannot be absorbed (Olean) or can be only partially absorbed (Caprenin, Benefat) in the intestine. Olestra, now marketed under the name Olean, is the best known of these products. Olestra is made of six to eight fatty acids bound to a sucrose (sugar) molecule. Normal fats have only three fatty acids. Adding the extra fatty acids makes the olestra molecule too large to be absorbed, so it simply passes through the intestine and is eliminated as waste. In this way, it adds no calories to food. Proctor & Gamble spent 25 years and more than $200 million developing this fat replacement.
Olestra has all the properties of regular fat and can be used in frying. It is used mainly in crunchy snack foods such as potato chips. Other fat-based fat replacers such as Caprenin and Benefat are partially absorbed by the body and contain about five calories per gram. Emulsifiers can also be used as fat replacers. They contain the same number of calories per gram as fat, but fewer grams of emulsifier are needed to achieve the same taste, texture, and mouth feel as fat.
Health considerations
All fat replacers on the market are on the generally recognized as safe (GRAS) list approved by the United States Food and Drug Administration (FDA). When olestra was first introduced for use in snack foods in 1996, it was required by the FDA to carry the following warning: ‘‘This Product Contains Olestra. Olestra may cause abdominal cramping and loose stools. Olestra inhibits the absorption of some vitamins and other nutrients. Vitamins A, D, E, and K have been added.‘‘ In 2003, after additional controlled studies and consumer education, the FDA allowed the warning to be removed from olestra-containing foods. The FDA requires small amounts (far less than the RDA) of vitamins A, D, E, and K be added to foods containing Olestra. This helps compensate for the small amount of these fat-soluble vitamins that dissolve in Olestra and is carried out of the body rather than being absorbed. Other vitamins are not affected.
A diet too high in fat can increase levels of blood lipids and increase risk of plaque build up on the walls of arteries and result in the development of cardiovascular disease. Reducing the amount of fat intake along with other lifestyle changes can help reduce this risk. In addition, obesity increases the risk of developing diabetes and other health problems. Studies have shown reduced-fat foods can be part of an effective weight-loss program that combines a healthy diet, reduced calorie intake, and exercise. The American Heart Association states, ‘‘Within the context of a healthy dietary pattern, fat substitutes, when used judiciously, may provide some flexibility in dietary planning, although additional research is needed to fully determine the longer-term health effects.’’
Precautions :
People who have disorders that interfere with the absorption of nutrients from the intestine, such as celiac disease, Crohn’s disease, or inflammatory bowel disease, should consider avoiding foods containing Olestra.
Fat replacers are often found in high-calorie foods. These foods may contain extra sugar to compensate for the absence of fat. Many reduced-fat products contain as many or almost as many calories as the full-fat equivalent. Consumers concerned about calorie intake should read the label and not assume that reduced-fat implies a reduced-calorie product.
Interactions :
Olestra reduces the absorption of the fat-soluble vitamins A, D, E, and K, and carotenoids. Olestra containing products have extra fat-soluble vitamins, but not carotenoids, added to compensate for this.
Complications :
Large amounts of Olestra and the carbohydrate based fat replacer polydextrose can cause loose stools and diarrhea in some people. Individuals should start with a small amount of foods containing these substances and see how they are affected. Parental concerns Reduced-fat foods may appear healthy, but they may contain as many calories and more sugar than the equivalent full-fat product. Parents should encourage their children to eat a healthy diet high in fruits and vegetables and low in fats and not rely on fat substitutes to control fat and calorie intake.
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