1. Male and female baboons were fed a 75% sucrose/fat free diet for 13 weeks. At the end of this period, and when tested by a sucrose meal, the glucose tolerance was improved, but the fructose tolerance impaired.
2. There was no difference between the male and female baboons with regard to the changes observed in glucose tolerance. The impairment of fructose tolerance as a result of the sucrose diet was more marked in the males than in the females.
3. By labelling the sucrose meals uniformly with 14C, a correlation was observed between the level of peripheral blood fructose attained and the degree to which 14C-triglyceride appeared in the serum. No such correlation was found with glucose.
4. A cause-and-effect relationship between fructose tolerance and triglyceride specific activity was demonstrated by means of a high sucrose diet. The resulting impairment of fructose tolerance was reflected by a corresponding increase in triglyceride specific activity. The improvement in glucose tolerance under the same dietary conditions bore no relationship to the change in triglyceride specific activity.
5. Fructose was incorporated into serum triglyceride to a greater extent in the male baboons than in the females because of the higher levels of blood fructose attained in the male animals.