This study explored the roles of nutrients in the demand for food through utility theory. The findings support the argument that nutrients play important roles in the demand for food. The 1987-88 Nationwide Food Consumption Survey data were used. The impacts of six nutrients (carbohydrates, fats, vitamins, minerals, digestible fibers, and proteins) on the demand for five food groups (dairy, meats, vegetables and fruits, grain products, and other foods) were studied using the Rotterdam demand system.