The average annual intake of specific nutrients, foods, food groups, and proxies for nutrient bioavailability of 87 Mexican preschoolers and 110 schoolchildren were compared with their anthropometry. Median intakes of energy, protein, thiamine, and iron were adequate; calcium and zinc were low; and other nutrients were very inadequate. Anaemia and low serum retinol were common. Intake of individual nutrients failed to predict size. Correlation matrices, median traces, and principal-components analysis illustrated a dietary continuum ranging from a high dependence on tortillas to more animal products and fruit. Children consuming a lower proportion of tortillas and legumes and more animal products were taller and heavier. Even though the high-tortilla dietary pattern provided more of most nutrients, these were less available. In conclusion, children's size was predicted by dietary quality - not quantity - measured either as a high intake of animal products or as a lower intake of factors inhibiting nutrient bioavailability.