What is energy density?
Energy density is the calorie content of a specific quantity of a food. Usually it’s listed as kilocalories per gram (kcal/g). At a given amount, foods with low energy density contain less calories than those with high energy density. Or in other words: you can eat more from a food with low energy density than from foods with high energy density and consume the same calories.
Energy density is important when you want to manage your weight. Is daily energy expenditure low, it’s important to choose more foods with low energy density. Are we more active or maybe do more than one workout a day, it’s important to add more foods with high energy density to cover energy needs. If an elite athlete chose mostly vegetables for meals and snacks, it would be difficult (impossible) to cover energy needs. Yet, if less active people choose mostly energy dense foods, it will be difficult to avoid weight gain.
Fat contains the highest amount of calories. One gram fat contains 9 kcal, that’s more than twice the kcal content of carbohydrates and protein. These contain 4 kcal/g. Water, vitamins and minerals do not contain any energy.
Water content and macronutrient composition affect energy density of a food. Water hast the highest impact on energy density (energy density is 0 kcal/g). It changes the weight of a food but not its energy content. In contrast, it reduces energy density. You can for example reduce the energy density of high-fat foods by adding water (“diluting”).
- Vegetable /chicken broth
- Yogurt (plain, low fat)
- Lean Meat
- Dried fruits
- Bread and bread rolls
- Fruit cake
- Fruit yogurt (low fat)
- Nut butter
- Cheese (Gouda, Parmesan, Swiss)
Besides energy density, nutrient density is important as well. It’s the nutrient content of a food. It’s important to know that energy density of a food doesn’t say anything about its nutrient content. A food with high energy density can have high nutrient density (olive oil), but there are also examples with high energy content but low nutrient quality (Coca Cola). For athletes, it’s important to choose foods with high nutrient density (“quality”) to cover the increased needs of specific nutrients.