LongHorn's guest relations team confirmed by email that their deep fryers run on highly refined soybean oil and their grill uses canola oil, so effectively every hot item on the menu is cooked in a seed oil. They call the rest of their recipe detail proprietary and publish no ingredient statements, so the additive and premade scores here are estimates rather than readings.
LongHorn publishes no ingredient statements at all, so this rating comes from an email their Guest Relations team sent on 20 August 2026. It says, word for word, that highly refined soybean oil is used in their deep fryers, that canola oil is used for grilling, and that olive oil is used in some recipes. That covers the entire cook line: the grill is where the steaks, chicken and salmon are done and the fryer covers the fries and the shrimp, so there is no way to order a hot item that has not been cooked in soybean or canola. Their public Nutrition Guide backs up the fryer half with a preparation column literally headed "Fried In Soybean Oil". The same email says the rest of the recipe detail is proprietary, which is why nothing else here is answered from a real list. Additives and how premade the food is could not be checked against anything at all, so both of those are estimates from how a steakhouse this size runs rather than readings, and they are stored as hunches.