Using data from an Alachua County, Florida elementary school, we analyze how intermittently offered à la carte items, such as ice cream and other desserts, affect the selection of more healthful National School Lunch Program (NSLP) lunch components (fruits and low-fat dairy). We find NSLP participants are more likely to select the fruit component on days à la carte items are offered; however, NSLP participants who purchase à la carte items, when available, are less likely to select a fruit. If students consume all of the foods that they select, this substitution effect reduces micronutrients consumed and increases caloric intake. Such a substitution over the long term could have implications for childhood obesity as well as overall health. Our results have implications for the on-going debate pertaining to competitive foods sold in school lunchrooms.