To appeal to our desire for lower-fat substitutes for our favorite high-fat foods, the commercial food industry has developed low- or lower-fat versions of many foods using various fat replacers. Until recently, fat replacers always consisted of proteins or carbohydrates, such as starches or gels, but the kinds of foods that could be prepared with these fat replacers were limited by their inability to withstand the high temperatures of frying. In 1996, after a long period of development, safety testing, and governmental review, the first non-caloric fat, olestra, was approved by the FDA for use in the manufacture of savory (non-sweet) snacks (such as crackers and chips).
Because olestra is a modified fat, it is the first heat-resistant fat substitute, which allows it to be used to make fried foods. In addition, olestra gives foods the flavor and creamy “mouth feel” of high-fat foods. FDA approval of olestra was controversial for two reasons. First, this artificial ingredient, if approved and accepted, would be the first in history to be consumed in quantities comparable to the quantities of fat, carbohydrates, and proteins we currently consume from food sources.
In other words, these novel, previously unknown substances could become major parts of the diets of some people, and there would be no historical experience to tell us what the substances might do in our bodies. Some scientists predicted that the substance would cause serious gastrointestinal complaints despite controlled studies demonstrating its safety. However, in the first year of availability of olestra containing foods, the predicted intestinal problems were not significant.
Tests in which volunteers ate large quantities of olestra-containing potato chips or regular potato chips without knowing which type they were eating showed no differences in gastrointestinal complaints between the two groups.
Second, tests of olestra showed that it inhibits the absorption of fat-soluble compounds (vitamins A, D, E, and K and some carotenoids) from foods eaten at the same time as the olestra-containing foods, whereas it has no effect on the absorption of other nutrients or on the body’s stores of fat-soluble vitamins.
To compensate for this effect of olestra on fat-soluble vitamin absorption, foods prepared with olestra have small amounts of these vitamins added to them. At this writing, the range of foods that can include olestra as a fat substitute is quite narrow