Background: The study investigated how nutrient standards affected the number of kilocalories and grams of fat and saturated fat in competitive foods offered and sold in 3 high schools. Methods: The study is a quasi-experimental design with 3 schools serving as the units of assignment and analysis. The effect of the nutrient standards was measured by the change in kilocalories and grams of fat and saturated fat in offerings and purchases of competitive foods pre- and postimplementation of the standards. A paired sample t-test was used to compare kilocalories and grams of fat and saturated fat pre- and postimplementation of nutrition standards. Results: After the implementation of the nutrition standards, students in 3 high schools purchased significantly smaller numbers of kilocalories and grams of fat and saturated fat, during the postpolicy school year of 2007-2008 than during the prepolicy school year of 2004-2005. Conclusion: Using nutrient standards to guide the selection of competitive foods offered in school cafeterias may positively affect intake of kilocalories, total grams of fat, and total saturated fat of those foods. The quantitative assessment is novel and demonstrates the reduction in kilocalories and fat in both the competitive food offerings and purchases as a result of nutrient standards. (Contains 3 tables and 1 figure.)