Assessment of the nutritional effects of olestra, a nonabsorbed fat replacement: summary.

Olestra is a zero-calorie fat replacement intended to replace 100% of the fat used in the preparation of savory snacks. Olestra can affect the absorption of other dietary components, especially highly lipophilic ones, when ingested at the same time. The potential effects of olestra on the absorption of essential fat-soluble and water-soluble dietary components have been investigated in pigs and in humans. In these studies, subjects were fed daily amounts of olestra up to 10 times the estimated mean intake from savory snacks and the olestra was eaten each day of the studies. In real life, snacks are eaten on average five times in a 14-d period. Olestra did not affect the availability of water-soluble micronutrients or the absorption and utilization of macronutrients. Olestra reduced the absorption of fat-soluble vitamins A, D, E and K; however, the effects can be offset by adding specified amounts of the vitamins to olestra foods. Olestra also reduced the absorption of carotenoids; analysis of dietary patterns showed that in real life the reduction will likely be <10%. Any effect on vitamin A stores caused by a reduction in carotenoid uptake is offset by the addition of vitamin A to olestra foods. Because of the olestra-to-nutrient ratios fed and the nutritional requirements of the test subjects, the effects of olestra on nutritional status of subgroups of the population are unlikely to be different than those measured in the studies. An analysis of lipophilicity showed that olestra is unlikely to significantly affect the uptake of potentially beneficial phytochemicals from fruits and vegetables. Some people eating large amounts of olestra snacks may experience common GI symptoms such as stomach discomfort or changes in stool consistency, similar to symptoms accompanying other dietary changes. These symptoms present no health risks.