Long-term effects of cafeteria diet feeding on young Wistar rats

The long-term effects of cafeteria diet feeding were studied by comparing the circulating levels of glucose, lactate, glycerol, 3-hydroxybutyrate and urea, and liver glycogen in female Wistar rats offered the diet from birth (CB) or from 30 days (C30) after birth, compared with controls fed on a standard reference diet. Body weight was maximal for CB, distinctly higher than that of C30, which in turn were heavier than controls. Growth rates, however, were similar for most of the period studied. Plasma glucose homeostasis was maintained fully in all three groups, with a remarkable lack of changes in liver glycogen concentration. The patterns of lactate and glycerol concentration changed with age. Different initial settings converged to adult values in all groups. The higher ability of cafeteria rats to use lipids as energy fuel is in agreement with their higher circulating levels of 3-hydroxybutyrate, a factor that may be essential in the shift to increased fat deposition that characterizes prolonged cafeteria feeding. Urea levels were highest in controls, and lowest in cafeteria rats fed from day 30, a consequence of the different setting of nitrogen sparing induced by the timing of initiation of cafeteria feeding. From the results presented it can be postulated that the type of diet onto which the rats are weaned may significantly affect their weight and metabolic correlations much later in life.