In a study of Olestra, the fat substitute recently approved for human consumption by the FDA, researchers from Pennsylvania State University concluded that human taste buds apparently don't detect the difference between the low-calorie fat replacer and regular fat when used in potato chips.
In a study of Olestra, the fat substitute recently approved forhuman consumption by the FDA, researchers from Pennsylvania StateUniversity concluded that human taste buds apparently don't detectthe difference between the low-calorie fat replacer and regularfat when used in potato chips.
"This is important because it suggests that if we can getthe taste and texture of fat-free and reduced-calorie foods right,then they can be just as satisfying to our sense of taste andtexture as the regular version of that food, despite being lowerin fat and calories," said nutrition researcher Debra Millerof Penn State's University Park campus, who reported the findingsat Experimental Biology '96, an annual meeting of biologic andbiomedical researchers.
Miller and her colleagues also found no difference in how fastpeople's taste for the two types of chips diminished, suggestingthat neither fat nor calories provide sensory signals to tastebuds that cause people to grow tired of a specific food. "Iffat and calorie content are important to achieving sensory-specificsatiety, then we would have expected different results from thetwo types of chips," Ms. Miller said.
The study--involving what Penn State's Barbara J. Rolls, phd,labeled the fat substitute most systematically investigated--providesadditional evidence that humans find olestra agreeable to theirpalates and their stomachs.
Need for Real-Life Evidence
But as Dr. Rolls, Ms. Miller's coauthor, noted separately in apress conference, a great gulf separates the impressive supportbuilt up for Olestra and other fat substitutes in the laboratoryand what might happen in the real world.
"There is really no evidence at all on how these productsaffect people in real life situations," Dr. Rolls said. "Ultimately,we need to know how the whole array of fat-substituted foods impactpeople's diets, both in terms of energy intake and the macronutrientcomposition, and if they're having an impact on body weight. Itisn't an easy study. The kinds of ways people incorporate thesefoods into their diet isn't known at all."
Effects on Children Still Sketchy
Questions remain, as well, about the effects of fat substituteson children, particularly young ones. A short-term study reported3 years ago by Leann L. Birch, phd, head of Penn State's Collegeof Health and Human Development, used Olestra in addressing theissue of whether children compensate for the calories eliminatedfrom their diet with the use of fat replacers by eating more food,or if they actually have a reduction in total energy intake, whichcould cause developmental problems.
"Calories were essentially the same," Dr. Birch said,adding that the work she and her colleagues did was the only attemptshe knew of to resolve the question.
A variety of fat replacements exist, including carbohydrate-baseddextrins, modified food starches, polydextrose, and gums. Othersinclude in their formulation monoglycerides or triglycerides.Olestra, formed by the esterification of sucrose with fatty acidsfrom edible oils, can be used in cooking, baking, and, unlikeother fat replacements, frying. Despite its sucrose lineage, theproduct lacks sweetness and looks, tastes, and feels like fat.
The FDA granted Procter & Gamble approval in January to marketolestra for use in savory snack foods, such as cheese curls andpotato and corn chips. Products fried in olestra, which P &G is selling under the brand name Olean, have recently enteredthree small test markets.
No Miracles Expected
No one should expect weight-wasting miracles from olestra or otherfat replacers, advised John C. Peters, phd, Procter & Gamble'sassociate director for regulatory and clinical development, foodand beverage products. "People expect these things to makepeople who are obese melt away and turn into nice, skinny people.That's generally not going to happen."
Fat replacers can only help people control or lose weight if theyare part of a sensible diet, he stressed. "As someone said,this is a replacement for fat, not for common sense."
More than a dozen studies have addressed whether when fat is replacedwith olestra people "make up that fat by eating other fattyfood, so that they get the same amount of fat at the end of theday," Dr. Peters said. "The answer across the boardis that there is no fat-specific appetite. So if you take theenergy out by taking the fat out, people might make up some ofthe energy, they might even make up all of the energy, but theydon't make up the fat. So you get the fat-reduction benefit."
Thin people who didn't need to cut calories maintained their samelevel of calories in some studies with olestra, but all stillcut their fat intake.
However, the laboratory is not the lunch room. People can overridethe weight-control and/or reduced fat benefits of fat reducersby eating more of low-fat foods or by eating other fatty foods.
"Clearly, if people take things into their own hands, whatI call cognitive override, they can do anything they want,"Dr. Peters said. "What they do in their head, we will haveto see."