What is energy density, and give an example of a high-energy-dense food and a low-energy-dense food.

• A. Energy density is calories per gram; high-energy-dense: nuts; low-energy-dense: leafy greens.
• B. Energy density is weight per serving; high-energy-dense: celery; low-energy-dense: oil
• C. Energy density is volume per serving; high-energy-dense: water; low-energy-dense: butter
• D. Energy density is grams of protein per serving; high-energy-dense: beans; low-energy-dense: rice

Answer: (A)

Energy density is the number of calories in a given amount of food, typically expressed as calories per gram. It shows how energy-rich a food is for how much you eat. Nuts are high-energy-dense because their fat content packs a lot of calories into a small weight, while leafy greens are low-energy-dense since they are mostly water and fiber with relatively few calories per gram. This means you can consume a large volume of leafy greens and get relatively few calories, or eat a small amount of nuts and get many calories. Other ways of describing a food—like weight per serving or volume per serving—don’t reflect how many calories are in that amount, and energy density isn’t about grams of protein per serving.