Gender bias in food intake and its subsequent effects on growth and illness were examined using data from rural Guatemalan children. Multiple regression controlled for energy requirements, illness, and maternal and economic factors. Gender bias in energy and protein intake favored boys; the magnitude for ages 2-5 y was 247 kJ/d. Analysis of subsequent effects showed that boys had higher rates of weight gain due to gender bias in energy intake than did girls for ages 1-2 y (0.27-0.97 kg/y), when there were no differences in illness rates due to gender bias in energy intake. For age 3-5 y, boys and girls did not differ in weight gain due to gender bias in energy intake. For ages 1-2 y for weight and stature, the growth rate for boys was faster than that of girls by 6-49% due to gender bias. This study provides evidence of gender bias in food intake in a Latin American population, but more work on the existence of and reasons for gender bias in food intake is needed before advocating that education or health programs should focus on this issue.