Depends on which food you are talking about. Grams of what? Everything is going to be different. The calorific values for fat, protein, carbohydrates and alcohol are as follows:
Fat: 1 gram = 9 calories
Protein: 1 gram = 4 calories
Carbohydrates: 1 gram = 4 calories
Alcohol: 1 gram = 7 calories
....therefore 1kg of fat = 1000 grams = 9x 1000 = 9000 cals per kilo. The answer to your question is 11. 12 grams of fat = 100 calories.