16.9 Energy and Nutrient Density

Energy density refers to the amount of energy—in terms of calories—in given food relative to its weight or volume, and is typically measured in grams. Foods with high energy density have a lot of calories for a seemingly small amount of food.

The different macronutrients—carbohydrates, fats, and proteins—provide different amounts of energy:

• Carbohydrates and proteins both provide four calories per gram.
• Fats provide nine calories per gram.

Vitamins, minerals, and water do not provide calories. The only other source of calories is alcohol. Though not a macronutrient and not essential, alcohol delivers seven calories per gram. Note that this number does not include the calories from other ingredients that may be mixed with alcohol.

More calories per gram means greater energy density. Fats are more energy dense compared to carbohydrates and proteins, and foods high in fat are nutritious when they contain healthy types of fat and other nutrients. Consider walnuts: they have a high proportion of fat relative to carbohydrates and protein, but it’s healthy essential omega-3 polyunsaturated fat, and they provide fiber, protein, vitamin E, and other beneficial nutrients, as well. Avocados and olives are other examples of foods that are relatively high in fat and therefore energy dense, and are also nutritious. Many energy dense foods are not nutritious, though; they tend to provide a lot of calories but little in terms of healthful nutrients.

How many total calories we consume in a day matters, but nutritious eating is about more than just calories. What we eat matters! Some foods provide superior nutrition compared to others based on their energy or nutrient density. This is a helpful concept to consider when choosing foods and beverages.

Nutrient density refers to the number of nutrients a food provides in proportion to the number of calories it contains. Foods with high nutrient density have a high nutrient-per-calorie ratio; they are relatively high in healthful nutrients and low in calories. The most nutrient dense and nutritious foods are whole foods direct from nature or close to their natural state. These include:

• Vegetables
• Fruits
• Whole grains
• Legumes, such as beans, peas, and lentils
• Unsalted nuts and seeds
• Fish and seafood
• Lean meats and poultry

These foods are high in vitamins, minerals, and may provide other health benefits. The other important thing about these foods is what is not in them; they contain little to no unhealthy trans and saturated fats, added sugar, refined starch, or sodium.