Olestra ingestion and dietary fat absorption in humans

The effect of olestra, a zero-calorie fat replacement, on the absorption of dietary fat was determined with a dual-isotope technique in 67 healthy male subjects. After a 30-d adaptation period in which they consumed potato chips which delivered either 10 g/d olestra or 10 g/d triglyceride under free-living conditions, the subjects were housed in a metabolic ward and given 0, 8, 20 or 32 g olestra in potato chips, The chips were eaten as part of a breakfast containing about 38 g of fat, about 0.16 mg of C-14-triolein, and a nonabsorbable marker, (CrCl3)-Cr-51. Feces were collected for 7 d, and aliquots of the two daily collections containing the highest levels of Cr-51 were oxidized. The CO2 was collected, and C-14 content was determined by liquid scintillation spectrometry. The fractional absorption of C-14-triolein was calculated from the average ratios of C-14/Cr-51 dosed and measured in the feces, Olestra had a slight but significant dose-response effect on triglyceride absorption: the highest olestra dose (32 g) reduced absorption by 1.2%. This effect is not nutritionally significant with respect to either availability of essential fatty acids or energy intake.