INS and fetal growth restriction: Similarly, at the age of 121 days during phase II, when all groups were fed the chow diet, there were no differences in fasting plasma insulin, but a tendency for fasting plasma glucose to be higher in the IUGR groups than in the non-IUGR group, with the value being higher in IUGR group weaned on the whey diet than on the casein diet (Figure 4C; p = 0.06).