To calculate the energy offered from food, multiply the number of grams of protein, carbohydrate, and fat by 4, 4, and 9, respectively.
Then add the results together.
Given: 500 grams of carbohydrates, 30 grams of protein, and 75 grams of fat in one day.
500 grams x 4 kcal/g = 2000 kcal
30 grams x 4 kcal/g = 120 kcal
75 grams x 9 kcal/g = 675 kcal
= 2795 kcal
From this data, you can calculate the percentage of k calories each of the energy nutrients give to the total.
Solution:
2000/2795 * 100% = 72% from carbohydrates
120/2795 * 100% = 4% from protein
675/2795 * 100% = 24% from fat
Total: 100%