If you want to start a weight loss diet in a healthy way, understanding how calories are calculated will be of great help. Although the labels printed on most foods list the number of calories they contain, they very often do not indicate which nutrient they are derived from. To fully understand the difference between calories and grams, you need to learn how to convert them; in this way you can easily calculate the number of calories made by each single ingredient.
Steps
Method 1 of 3: Convert Fat to Calories
Step 1. Look at the nutrition facts label
Most of the labels found on foods show the amount of fat (expressed in grams) present in the food, based on a specific portion of the product. This information allows you to calculate the number of calories.
Step 2. Multiply the grams of fat by 9
Each gram of fat contains 9 calories. So, to calculate the number of calories in a given amount of fat, simply multiply it by 9.
For example, if a certain food contains 10 g of fat, the calorie intake will be 10 x 9, i.e. 90 calories
Step 3. Calculate the calorie intake of the entire product
To do this, multiply the number obtained in the previous step by the number of total servings contained in the entire package. This information is printed on the nutrition label you find on the product.
For example, if the package of the food in question contains three servings, you will need to multiply 90 x 3 to get a total caloric intake of 270 calories
Method 2 of 3: Convert Carbohydrates and Proteins to Calories
Step 1. Keep in mind that carbohydrates are a complex organic compound
Carbohydrates are composed of carbon, hydrogen and oxygen. The caloric intake of one gram of carbohydrates is equal to 4 calories. This does not mean that calories are only consumed from carbohydrates, because they are also contained in other basic nutrients.
Step 2. Check the nutrition facts labels
In this way you will be able to find out the carbohydrate intake given by each individual portion of a certain product. Each gram of carbohydrate contains 4 calories; then, to find out the number of calories contained in a portion of a given food, multiply the amount of carbohydrates (expressed in grams) by 4.
For example, if a product contains 9 grams of protein, you simply multiply this number by 4, resulting in 36 calories. This equation holds true because each gram of protein provides the body with 4 calories
Step 3. Find out the total calorie intake from protein
The amount of this basic nutrient is also listed on the nutrition labels of foods. Proteins, like carbohydrates, provide a caloric intake of 4 calories per gram. So, even in this case, to get the total calorie intake of proteins, you will have to multiply the quantity (expressed in grams) by 4.
Method 3 of 3: Understanding the Difference Between Grams and Calories
Step 1. Understand what grams are and what calories are
The gram is a unit of measurement in the metric system to indicate a weight equal to one thousandth of a kilogram. The calorie is the unit of measurement of the energy that is consumed through food. 450 grams of body fat equals approximately 3,500 calories.
Grams and calories are therefore two different units of measurement that cannot be converted between them
Step 2. Identify the energy source you want to measure in terms of calories
The number of calories per gram a food provides depends on the percentage of nutrients it contains. The human body generates the energy for its sustenance from three basic nutrients: carbohydrates, fats and proteins.
Simply weighing food and converting its weight into calories is not possible. First you need to find out the number of calories contained in each specific nutrient (based on weight in grams) and then proceed to calculate the total calories
Step 3. Multiply the number of grams by the specific coefficient
Look at the label of the food you want to calculate the calorie intake for. The amount of each of the basic nutrients it contains is expressed in grams. Now you simply have to multiply the total weight of each item by the number of calories contained in each gram.
