Effects of isocaloric exchange of dietary sucrose and starch on fasting serum lipids, postprandial insulin secretion and alimentary lipaemia in human subjects.

I. Fasting serum cholesterol and triglyceride, and post prandial insulin secretion and lipaemia were measured in human subjects in a metabolic ward, who were given an ordinary diet (diet I ) in which the sucrose was isocalorically replaced by starch (diet 2) or vice versa. The subjects were nine healthy normolipaemic adult males. In eight of these subjects the effect of sucrose calorie reduction (diet 3) on fasting serum lipids was also studied. 2. When starch replaced sucrose, there were no significant differences in fasting serum lipid concentrations or immunoreactive insulin or in the insulin response and alimentary lipaemia after a standard mixed breakfast. 3. Serum triglyceride concentration fell and cholesterol concentration rose during the period of sucrose (and calorie) restriction. 4. After lunch and supper on the first two diets (%hen different carbohydrates were given) the lipaemic response was larger and the insulin response smaller after meals containing sucrose. 5. Thus, there was no difference between concentrations of fasting serum lipids when starch replaced sucrose at 23 '4 total calories, but the concentrations of serum triglycerides were higher after individual mixed meals containing sucrose. 6. There were no significant differences in the fatty acid patterns of serum lipids on the different diets.