There is no need to feel deprived or hungry when you are trying to lose weight. Understanding more about the energy density of the foods you eat will help you reach your goals while feeling full and satisfied.

What does energy density mean?

The energy provided by food is measured in calories. A food's energy density is the number of calories per gram. This can be calculated using the following equation:

Energy Density = calories per serving ÷ weight of serving in grams

A food with a lower energy density has fewer calories per gram. As a general rule, foods with higher water content and fiber have lower energy densities because these two components add weight without excess calories. The Centers for Disease Control and Prevention provides a good example of this concept. One and a half fresh oranges have about 100 calories, and three pretzel rods also have 100 calories. The oranges weigh 200 grams, and the pretzels weigh 25 grams, so the oranges have a lower energy density than the pretzels.

How does energy density affect weight loss?

Consuming low-energy-density foods is a strategy to feel full while reducing calories for weight loss. Research shows that we consume about the same weight of food each day, but not the same number of calories. You can lower your calorie intake without reducing the weight of the food you eat. Studies show that people can lose weight without feeling deprived if foods with lower energy density are used.

One study reported that subjects who were given a low-energy-density salad before a meal consumed fewer calories at the meal but reported feeling as full as those who ate no salad or a higher-energy-density salad.

Do I need to track energy density?

Tracking calories is one way of keeping energy density in check. Knowing that foods with more water and fiber are less energy-dense is the first step toward making smart choices. There is no need to calculate energy density for every food. Simply increase low-energy-density foods (fruits and vegetables) and decrease high-energy-density foods (fast food, processed snack foods, baked goods).

The equation becomes helpful when you are trying to choose between foods that both offer nutritional benefits. For example, raisins and grapes fit into a healthy diet, but fresh grapes are less energy dense than raisins.

What is the difference between energy density and nutrient density?

Nutrient density refers to the amount of macronutrients, vitamins, and minerals in a food. Regardless of weight goals, nutrient-dense foods are important for health. Fortunately, most low-energy-density foods have high nutrient density, but it is important to think about your food choices. For example, celery has a low energy density, and you can eat a lot for very few calories. Unfortunately, celery does not provide many of the nutrients the body needs for health. Choosing a variety of fruits, vegetables, beans, and low-fat dairy supports a low-energy-density diet while also being nutrient-dense.

Tips for lowering energy density.

• Mix vegetables into your favorite soups, stews, and casseroles to lower the energy density of the whole dish. Try using shredded summer squash, diced carrots, tomatoes, and dark leafy greens.
• Swap crackers, pretzels, and chips with carrot sticks and bell pepper strips to serve with your favorite bean dip.
• Take fruit and vegetables with you for snacks. This will help you avoid the temptation of turning to the vending machine for processed foods when hunger hits.
• Choose fresh fruits over dried options. Both contain fiber, but the higher water content of the fresh varieties lowers their energy density.

Sources

• Kansas State University — Low-Energy-Dense Foods and Weight Management
• Mayo Clinic — Weight loss: Feel full on fewer calories
• British Nutrition Foundation - What is energy density?
• Penn State University - Eat Water, Lose Weight

Lori Rice, M.S., is a nutritional scientist and author with a passion for healthy cooking, exercise physiology, and food photography.