Final answer:
Each gram of protein provides 4 kilocalories. This value is obtained through calorimetry, where food is burned to measure energy content, and is used for nutritional labeling.
Step-by-step explanation:
Each gram of protein in a solution provides 4 kilocalories. This value is determined using calorimetry techniques, which include burning the food in a controlled setting and measuring the heat transfer. This technique helps in calculating the caloric content accurately.
For example, when you're looking at a food label and you see a certain number of grams of protein, you can calculate the total calories from protein by multiplying by four. So, if you have 5 grams of protein, you'd have
5 grams × 4 kcal/g = 20 kcal from protein.
Similarly, carbohydrates also provide 4 kilocalories per gram, while fats are more calorie-dense, providing 9 kilocalories per gram. These measurements are standard and widely used for nutritional labeling and dietary planning.