A traditional arroz con leche recipe calls for whole milk. If you are keeping an eye on saturated fat, you can substitute low-fat milk. However, if you want to make a sweeter arroz con leche, you can use evaporated milk or condensed milk. Evaporated milk and condensed milk are sweeter than whole milk. If you use evaporated milk or condensed milk, make sure to taste as you cook, not to over-sweeten the Arroz con leche.