Long-term optional ingestion of corn oil induces excessive caloric intake and obesity in mice

Corn oil is well tolerated by mice but tolerance may decrease with excessiv e ingestion. In the present study, we compared the effects of optional inge stion of excessive corn oil with ingestion of water (control) or a 20% sucr ose solution in mice. During the entire study, mice consistently ingested 1 00% corn oil and incrementally ingested 20% sucrose. Food intake in the cor n-oil group was approximately constant but that in the sucrose group was sl ightly decreased. Body-weight gains in the corn-oil group were higher than those in the control and sucrose groups. At the end of the study, hepatic h ypertrophy and fatty liver were present, especially in the corn-oil group, and the visceral fat of mice fed corn oil increased significantly compared with the other two groups. These results suggest that mice, when given a ch oice, will continue to overeat corn oil over the long term, inducing excess ive caloric intake and obesity. (C) Elsevier Science Inc. 2001.