We have reported that oil thermally processed with
protein promoted safe and steady
weight loss in animal experiments. In the present study, an oil for use in weight control was prepared by heating fresh oil with wheat
gluten or
soybean protein to determine the influence of
protein differences on the
weight loss-promotion effect. The 2 kinds of oil obtained, which differed neither from commercial fresh oil (starting oil) nor from one another in appearance, chemical properties, and aroma, were mixed (7%) with powdered AIN93G no-fat, defined standard diet and fed to 10-week-old Wistar rats ad libitum. After a 12-week feeding period, the rats were sacrificed to obtain blood and organs. There were no differences in amounts ingested,
body weight increases, fecal excretion, organ weights, serum biochemical analyses, contents and
fatty acid compositions of
lipids of retroperitoneal fat tissue, or organ observations.
Aspartate aminotransferase (AST),
alanine aminotransferase (AST), and histological analysis supported the safety of the oil. In conclusion, the differences between wheat
gluten and
soybean protein in
amino acid composition, both of the
proteins and as free
amino acids, were unrelated to the
weight loss-promoting effect of the oil. Minor components in the
vegetable proteins may have contributed to the effect on
body weight.