Fructose and sucrose feeding during pregnancy and lactation in rats changes maternal and pup fuel metabolism

We examined the effects of feeding a fructose, sucrose or reference diet during gestation and lactation on blood substrate levels and insulin sensitivity in rat adipose tissue. Female rats were fed either 50% fructose or 50% sucrose purified diets or a nonpurified diet ad libitum during gestation and lactation. Fasting blood samples were taken on d 10 of gestation and one oral glucose tolerance test was conducted on d 19 of gestation, with a second test performed on the day of weaning. All dams were killed 2 d after weaning. During gestation, fructose feeding induced hyperglycemia and hypertriglyceridemia in early pregnancy (d 10) relative to sucrose-fed rats, and hypotriglyceridemia in late pregnancy (d 19) as compared with the group fed the reference diet. Compared with the reference group, sucrose feeding also caused hypotriglyceridemia during late pregnancy. Pups delivered to fructose-fed dams were hyperglycemic at birth. In comparison with the reference group, fructose-fed dams were hypoglycemic, whereas sucrose-fed dams were hypertriglyceridemic at weaning. There was no difference in each of the two oral glucose tolerance test responses between the three groups after adjusting for the baseline difference in glucose levels. However, lipid synthesis in isolated fat cells in response to insulin stimulation was significantly lower in fructose-fed and sucrose-fed rats relative to the reference group.