Taking the Fat Out of Food
Food manufacturers are making it easier for fat-conscious consumers to have their cake and eat it, too--and their cheeses, chips, chocolate, cookies, ice cream, salad dressings, and various other foods that are now available in lower fat versions.
These products can help adult consumers reduce their fat intakes to recommended levels while allowing them to enjoy foods traditionally high in fat. A diet high in fat can contribute to heart disease and some forms of cancer and, because fats are calorie-dense, to excessive body weight.
A host of fat substitutes that replaces most, if not all, of the fat in a food, makes these lower fat foods possible. Most of these fat replacers are ingredients already approved by the Food and Drug Administration for other uses in food. For instance, starches and gums are approved as thickeners and stabilizers. New compounds, such as olestra, have undergone or will undergo close scrutiny by FDA to assess their safety.
In theory, the perfect fat replacer is one that contributes everything fat does in a food but without the calories, saturated fat, and cholesterol. The question remains: Can fat-reduced products actually reduce people's overall calorie intake and have a significant impact on their total fat intake?
Fat in the Diet
Fat is a difficult substance to replace because it has many important functions. A major nutrient, it is important for proper growth and development and maintenance of good health. Fats carry the fat-soluble vitamins A, D, E, and K and aid their absorption in the intestine. They are the only source of the essential fatty acids linoleic and linolenic acids. They are an important source of calories for many adults and for infants and toddlers, who have the highest energy needs per kilogram of body weight of any age group. Fat provides 9 calories per gram, compared with 4 calories per gram for protein and carbohydrates.
As a food ingredient, fat is important in food preparation and consumption because it gives taste, consistency, stability, and palatability to foods and helps us feel full so we stop eating.
But there are limits on the amount we should eat because of fats' link to heart disease, cancer and overweight. The Dietary Guidelines for Americans recommend limiting total fat intake to no more than 30 percent of calories and saturated fat to no more than 10 percent. Cholesterol intake should be limited to no more than 300 milligrams a day. Saturated fat and cholesterol are the substances in fat that contribute to the formation of plaque, which clogs arteries, leading to heart disease.
Americans appear to be heeding the experts' advice because, according to a 1995 annual survey by the Food Marketing Institute--an organization of grocery retailers and wholesalers--65 percent of the consumers surveyed--the highest level to date--rated fat as their No. 1 nutrition concern. More than three-fourths of the consumers said they stopped buying a specific food because of the amount of fat listed on the nutrition label.
A 1995 survey by the Calorie Control Council--an international association of manufacturers of low-calorie, low-fat, and diet foods and beverages--found that 72 percent of respondents who said they look for "light" foods said they are most attracted to food products claiming to be "reduced in fat."
Manufacturers are responding by adding more and more reduced-fat foods to their product lines. That corresponds to the Department of Health and Human Services' Healthy People 2000 goal of increasing to 5,000 from 2,500 in 1986 the number of brand items reduced in fat and saturated fat.
Fat replacers can help reduce a food's fat and calorie levels while maintaining some of the desirable qualities fat brings to food, such as "mouth feel," texture and flavor.
Under FDA regulations, fat replacers usually fall into one of two categories: food additives or "generally recognized as safe" (GRAS) substances. Each has its own set of regulatory requirements.
Food additives must be evaluated for safety and approved by FDA before they can be marketed. They include substances with no proven track record of safety; scientists just don't know that much about their use in food. Examples of food additives are polydextrose, carrageenan and olestra, which are used as fat replacers. Manufacturers of food additives must test their products, submit the results to FDA for review, and await agency approval before using them in food.
GRAS substances, on the other hand, do not have to undergo rigorous testing before they are used in foods because they are generally recognized as safe by knowledgeable scientists, usually because of the substances' long history of safe use in foods. Many GRAS substances are similar to substances already in food. Examples of GRAS substances used as fat replacers are cellulose gel, dextrins, guar gum, and gum arabic.
Fat replacers may be carbohydrate-, protein- or fat-based substances.
The first to hit the market used carbohydrate as the main ingredient. Avicel, for example, is a cellulose gel introduced in the mid-1960s as a food stabilizer. Carrageenan, a seaweed derivative, was approved for use as an emulsifier, stabilizer and thickener in food in 1961. Its use as a fat replacer became popular in the early 1990s. Litesse (polydextrose) came on the market in 1981 as a humectant, which helps retain moisture. Others in this category include dextrins, maltodextrins, fiber, gums, starch, and modified food starch. FDA has affirmed many carbohydrate-based fat replacers as GRAS.
Although their original intent was to perform certain technical functions in food that would improve overall quality, some carbohydrate-based fat replacers are now used specifically to reduce a food's calorie content. They provide from zero to 4 calories per gram. They are used in a variety of foods, including dairy-type products, sauces, frozen desserts, salad dressings, processed meats, baked goods, spreads, chewing gum, and sweets.
Protein-based fat substitutes came along in the early 1990s. These and fat-based replacers were designed specifically to replace fat in foods.
One form, Microparticulated Protein Product (MPP), such as Simplesse and Trailblazer, is made from whey protein or milk and egg protein. These fat replacers provide 1 to 4 calories per gram, depending on their water content, and are approved for use in frozen dessert-type foods. FDA has agreed that whey-based MPP conforms to FDA's definition of whey protein concentrate, such as the fat replacer Dairy-Lo, a GRAS substance. Therefore, whey-based MPP can be used in other foods, including reduced-fat versions of butter, sour cream, cheese, yogurt, salad dressing, margarine, mayonnaise, baked goods, coffee creamer, soups, and sauces.
Another type of protein-based fat replacers, called protein blends, combine animal or vegetable protein, gums, food starch, and water. They are made with FDA-approved ingredients and are used in frozen desserts and baked goods.
Olestra is an example of a fat-based fat replacer. FDA approved olestra (brand name Olean), made by Procter & Gamble Co. of Cincinnati, in January 1996, for use in preparing potato chips, crackers, tortilla chips, and other savory snacks. Procter & Gamble said it expected to begin test-marketing olestra-containing products in 1996.
Olestra has properties similar to those of naturally occurring fat, but it provides zero calories and no fat. That's because olestra is undigestible. It passes through the digestive tract but is not absorbed into the body. This is due to its unique configuration: a center unit of sucrose (sugar) with six, seven or eight fatty acids attached.
Olestra's configuration also makes it possible for the substance to be exposed to high temperatures, such as frying--a quality most other fat replacers lack.
As promising as olestra sounds, it does have some drawbacks. Studies show that it may cause intestinal cramps and loose stools in some individuals.
Also, according to clinical tests, olestra reduces the absorption of fat-soluble nutrients, such as vitamins A, D, E, and K and carotenoids, from foods eaten at the same time as olestra-containing products. Tests by Procter & Gamble show that no reduction in absorption of fat-soluble vitamins will occur when proper levels of vitamins are added for compensation to olestra-containing foods.
To address these concerns, FDA approved olestra on conditions that vitamins A, D, E, and K be added to olestra-containing foods and that Procter & Gamble continue studies on consumption and long-term effects of olestra. These studies will be reviewed at an FDA Food Advisory Committee meeting in mid-1998.
To provide consumers with information about olestra's possible effects, FDA also required that the following interim labeling statement appear on products made with olestra:
"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."
FDA has invited public comment on the need for such a label statement and on the statement's adequacy and clarity. The agency will evaluate those comments before issuing a final label statement.
Concern with olestra's drawbacks led one of olestra's critics, the Center for Science in the Public Interest--a nonprofit consumer advocacy organization--to file an objection to FDA's approval. FDA's response to the objection is pending.
Some other fat-based replacers are being considered or developed: Salatrim (which stands for short and long-chain acid triglyceride molecules) is the generic name for a family of reduced-calorie fats that are only partially absorbed in the body. Salatrim provides 5 calories per gram. A petition seeking FDA's affirmation that Salatrim is GRAS was filed in June 1994. An example of its use is in Hershey Co.'s reduced-fat baking chips, semi-sweet chocolate flavor.
Caprenin, another Procter & Gamble product, is a 5-calorie-per-gram fat substitute for cocoa butter in candy bars. A petition seeking FDA's affirmation that Caprenin is GRAS was filed in 1991.
Emulsifiers are fat-based substances that are used with water to replace all or part of the shortening content in cake mixes, cookies, icings, and vegetable dairy products. They give the same calories as fat but less is used, resulting in fat and calorie reductions.
Other fat replacers are being developed, according to the Calorie Control Council and other organizations. They include DDM (dialkyl dihexadecylmalonate), a fat-based substance that is not absorbed into the body and can be used in frying and baking. Frito-Lay Inc. has been studying this fat substitute since 1986, although it has not yet petitioned FDA for approval. Also on the horizon is a fat substitute made by combining starches or gums with small amounts of oil. Opta Food Ingredients Inc. received an exclusive license from the U.S. Department of Agriculture last February for the process, called Fantesk. This fat replacer would give foods the taste and texture of regular fat but provide less than 0.5 grams of fat per serving.
Reducing Dietary Fat
Can these fat replacers help consumers make positive dietary changes? Can they help those who are overweight lose weight?
It may be too early to say, and studies to date give varying answers. For example, in a study of lean non-dieting men, one group ate breakfasts of conventional fat foods, while the other ate olestra-containing foods. Those who ate the olestra-containing foods made up their usual daily calorie intake by eating more carbohydrate-containing foods. The study, sponsored partly by Procter & Gamble and published in a 1992 issue of the American Journal of Clinical Nutrition (Volume 56), suggested that a diet of reduced-fat foods can help reduce fat intake without affecting total calories.
Fat intake also was decreased in a study of 96 men and women "habitual snackers." One group was fed potato chips prepared with olestra, while the rest ate potato chips prepared with conventional frying oil. The group fed olestra chips ate on average 29 grams less fat and 270 fewer calories a day than those fed regular chips--even though those who knew they were eating fat-free chips ate 10 grams of chips more than those who ate regular chips. This study, done at Pennsylvania State University, also was partly sponsored by Procter & Gamble.
A possible concern about fat replacers is: Can foods claiming to be reduced in fat inadvertently influence people to eat more? Another study at Pennsylvania State University suggests they might. In this study, women were fed the same yogurt labeled either "high-fat" or "low-fat." The group fed the low-fat-labeled version ate more in a lunch that followed the yogurt than the group eating the high-fat-labeled yogurt. As a result, the group eating what they thought was low-fat yogurt took in more calories than the other group.
"It appeared that these women regarded the low-fat label as a license to overeat," wrote Debra Miller, a doctoral student in biobehavioral health and nutrition at Pennsylvania State, in an article she prepared for Weight Control Digest.
Still, reduced fat foods appear to be an important part of a fat-reduction diet, according to a study involving the Women's Health Trial. The study, designed to determine the role of low-fat diets in the prevention of breast cancer, found that eating "specially manufactured" low-fat foods was one of the most easily adopted dietary practices for those who received prior dietary instruction. Avoiding meats and giving up fats as flavorings (for example, eating bread without butter or margarine) were among the most difficult practices to adopt.
In using reduced-fat foods, the American Dietetic Association cautions consumers to realize that fat-free doesn't mean calorie-free. The calories lost in removing regular fat from a food can be regained through sugars added for palatability, as well as fat replacers, many of which provide calories, too. Consumers should refer to the Nutrition Facts panel on the food label to compare calories and other nutrition information between fat-reduced and regular-fat foods.
Many nutrition experts agree that, used properly, fat replacers can play an important role in improving adult Americans' diets. But, as with any diet or food, they emphasize variety and moderation to ensure a healthy intake.
"These [fat replacers] are truly innovative ideas," said Dennis Gordon, Ph.D., a food scientist at North Dakota State University, Columbia. "But they shouldn't be looked at as a total panacea. [The advice] is the same as with anything: Be prudent."
Paula Kurtzweil is a member of FDA's public affairs staff.
FDA Consumer magazine (July-August 1996)