To find out the energy
available from a food, work it out by multiplying the number of grams of carbohydrate by 4kcal/g,
protein by 4 kcal/g, and fat by 9kcal/g. Then get the sum of the results.
So we have,
18g carbohydrate
x 4 kcal/g = 72 kcal
4g protein x 4 kcal/g = 16 kcal
1.5g fat x 9kcal/g = 13.5 kcal
Total = 101.5 kcal
Therefore, one slice of bread contains 101.5 kcal.
