How do I calculate the percentage of calories from fat?

An image showing nutrition facts. — Calories are the amount of energy released when your body breaks down food. teekid / Getty Images

If you're not sure how much fat you really eat each day, it may be helpful to calculate the percentage of calories in your typical diet that comes from fat. You don't need to do this every day of your life. However, doing it each day for 2 to 3 weeks can give you some useful insight into your current eating habits. It can also give you a clear idea of how much fat you need to cut. If you make adjustments to reduce your fat intake, try calculating your percentage of calories from fat again for a couple of weeks. This will help you determine whether the changes you've made to eat more healthfully have been great enough.

The Nutrition Facts labels that are required on most packaged foods must list many details, including:

the serving size for the food
the number of calories in a serving
the number of calories from fat in each serving
the grams of saturated fat in a serving

To lower your cholesterol, you need to understand the percentage of calories in your food that comes from fat. This includes both total fat and saturated fat. These are not listed on the label. You may see some percentages listed, but they tell you what percentage of your daily nutritional needs are met by one serving of the food if you eat a 2,000 calorie diet. This is not the information that you need about fat.

Here's how to figure out the percentage of calories from fat:

Calories from fat divided by total calories multiplied by 100 equals the percentage of calories from fat

Here's how to figure out the percentage of calories from saturated fat:

Grams of saturated fat multiplied by 9 calories per gram* divided by total calories multiplied by 100 equals the percentage of calories from saturated fat

*Each gram of fat, no matter which type of fat it is, has 9 calories.

When you eat out, you won't be able to get the information you need from Nutrition Facts labels. Instead, check your local bookstore for a book that lists the amount of calories, total fat, and saturated fat in common foods. You can use this to estimate the percentage of calories from fat and saturated fat in the foods you order.