We previously proposed that oil heated with
gluten was suitable for use as a safe oil for
weight-loss dieting. In the present paper, the properties of the oil were improved, and the
weight-loss effect was compared with that of heated oil. Fresh oil was heated for 10 h at 180 degrees C with or without
gluten and filtered using filter paper. A powdered diet (AIN93G; no fat) was mixed with 7 wt% of fresh oil (control) or filtrates of the heated
oils described above, and the mixture was fed to male Wistar rats for 12 weeks. The
gluten and heated oil groups showed no gross symptoms attributable to the experimental
oils but had a slowed
body weight increase; a significant difference was found in weight on and after 21 weeks of age as compared to rats consuming the control diet, and fecal excretion was increased as compared to the control group. Serum levels of
triacylglycerol,
phospholipids,
cholesterol, and
glucose of the
gluten and heated oil groups were significantly lower than those of the control group. High
aspartate aminotransferase (AST) levels occurred more frequently in the heated oil group than the
gluten group. The number of rats with dark red patches on the surface of the liver, which are indicative of liver damage, was higher in the heated oil group. In conclusion, the weight-reducing effect of the oil heated with
gluten was confirmed and improved by removing traces of heated
gluten from the oil.