A serving holds 5 g protein, 31 g carbohydrate and 12 g fat. Using 4, 4 and 9 Calories per gram, what is its energy content?

1. Protein gives 5 g times 4 Calories per gram, which is 20 Calories. 2. Carbohydrate gives 31 g times 4 Calories per gram, which is 124 Calories. 3. Fat gives 12 g times 9 Calories per gram, which is 108 Calories. 4. Adding the three gives 20 plus 124 plus 108, which is 252 Calories. 5. Using 4 Calories per gram for fat as well would give 192 Calories, understating the total. _Source: OpenStax Chemistry (CC BY 4.0), Ch 5 "Thermochemistry", section 5.2 Calorimetry_