Conclusions: At 7 months of age diet is an important predictor of serum lipid and lipoprotein concentrations. At the age of 13 months the apolipoprotein E phenotype significantly predicts the concentrations of serum non-high-density lipoprotein cholesterol and apolipoprotein B. However, at both ages apolipoprotein E phenotype, gender, and diet together explain only from 1.4% to 15.5% of the variance in serum lipids and apolipoproteins, suggesting that other, presumably genetic, factors are major determinants.