How to Calculate Energy Contributed by Fat

A kilocalorie (kcal) is a unit of energy measurement. It equals 4.184 kilojoules, another unit of energy measurement. One joule is the amount of energy used when a one Newton force moves one kilogram by one meter (1.09 yards). In 1896, W. O. Atwater at the United States Department of Agriculture (USDA) Agricultural Experiment Station in Storrs, Conn., determined the energy values of protein, fat and carbohydrate by measuring the amount of heat produced when each burned. According to the Atwater general system, one gram of fat produces nine kilocalories of energy.

Things You'll Need

• Food item
• Calculator (optional)
• Pencil
• Paper

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Instructions

• 1

  Select a food item to analyze. For example, take a 14.75-oz. can of canned salmon from your kitchen cupboard.

• 2

  Read the "Nutrition Facts" label on the foodstuff and learn the total fat content of one serving. For example, one serving of canned salmon contains 5 grams of fat.

• 3

  Multiply the amount of fat in one serving of the foodstuff by 9, using a calculator if necessary. For example, 5 x 9 = 45.

• 4

  Write your answer using the correct units. For example, write "45 kilocalories (kcal) of energy." Nutritionists and nutrition labels commonly refer to kilocalories as calories.