It would depend entirely on the types of bread and cheese used. For the bread, look on the bag to see how many calories are in a slice (remember that for most breads one slice is a serving size and that you are using two pieces of bread) and then check the label on the cheese to determine the calories and fat. An estimate would be about 250 calories from the bread, 100 calories from two slices of pre-packaged 2% fat cheese, and then if you put butter in the frying pan that could be anywhere from another 100 to 200 calories added to the grilled cheese, plus any condiments or anything else added to the sandwich. So you are probably looking at about 450 to 550 calories a sandwich with somewhere from 15 to 25 grams of fat.
Chat with our AI personalities