The calorie density (or energy density) of a food is a measurement of the average calories per weight (gram or ounce) of that food.
You can use calorie density to compare the number of calories in equal amounts of different foods and make better calorie choices. For example, 1 oz of chocolate has far more calories (i.e. a higher calorie density) than 1 oz of pretzels. This means that if you eat 1 oz of chocolate you will consume more calories than if you eat 1 oz of pretzels. Pretzels have a lower calorie density and are therefore a better choice when counting calories.
The biggest factor in determining calorie density is the water content of a food. Water increases volume of a food without adding calories.
The calorie density of foods influences your hunger, satiety and food intake. By eating foods with lower calorie density, you will feel full - but have eaten fewer calories.
When you search for a food in the Food Database, you will see an option to "show cd" or "show calorie density".
When you click on “show calorie density”, you’ll see stars appearing next to some foods. These stars provide a general guide to the calorie density of those foods. Here’s what the stars mean:
| Icon | Means... | Calorie density range |
 |
Best calorie choice: Very low in calories per gram | 0.0 - 0.6 cal/g |
 |
Good calorie choice: Low in calories per gram | 0.6 - 1.5 cal/g |
|
Average calorie choice: High in calories per gram | 1.5 - 4.0 cal/g |
 |
Poor calorie choice: Very high in calories per gram | 4.0 - 9.0 cal/g |
In other words, a food with four stars has a low calorie density and is a better choice if you are trying to reduce your calorie intake.
Note that some foods in the Food Database do not have calorie density stars. For these foods the calorie density is unknown. It does NOT mean that they are low (or high) in calorie density. You’ll find this is often the case for drinks.
Note: Calorie density (more calories per weight) is not the same as nutrient density (more nutrients per calories by weight). You want to aim for lower calorie density, but higher nutrient density.
Reference: Barbara Rolls. Energy Density and Nutrition in Weight Control Management. In The Permanente Journal, Spring 2003, Volume 7 No.2
