Objective: Assessing how the Italian average food pattern would be affected in terms of consumption structure and expenditure by the adoption of nutritional prescriptions. Design: A linear programming model with nutritional and food habits constraints was employed to generate a pattern following recommended daily allowances (RDAs) and nutritional guidelines provided for the Italian population. Setting: Food consumption data from ISTAT Household Budget Survey of Italian population. Subjects: Italian families investigated by the Family Budget Survey of the National Institute of Statistics. Results: Compared to actual behaviour, the pattern generated by the model implies an increased consumption of vegetables, pasta, rice and fresh ®sh, and a decreased consumption of meats, bread, sugars and cakes, and especially fats and oils. At given prices, total expenditure is lower than actual expenditure. Conclusions: Differences between actual behaviour and the generated pattern are consistent with long-term trends in food consumption. The adoption of RDAs is unlikely to result in an increased food expenditure.