The objective of this study is to examine the associations between fast foodconsumption and the academicgrowth of 8544 fifth-grade children in reading, math, and science. Method. This study uses direct assessments of academic achievement and child-reported fast foodconsumption from a nationally representative sample of kindergartners followed through eighth grade. Results. More than two thirds of the sample reported some fast foodconsumption; 20% reported consuming at least 4 fast food meals in the prior week. Fast foodconsumption during fifth grade predicted lower levels of academic achievement in all 3 subjects in eighth grade, even when fifth grade academic scores and numerous potential confounding variables, including socioeconomic indicators, physical activity, and TV watching, were controlled for in the models. Conclusion. These results provide initial evidence that high levels of fast foodconsumption are predictive of slower growth in academic skills in a nationally representative sample of children.