Boston University Sargent Choice Nutrition Center

Water: A Key Food Ingredient

You can’t tell how many calories are in a serving of food by its size or weight. A single chocolate truffle contains more calories than a head of lettuce. This concept is called energy density.

Foods high in energy density provide a lot of calories for a small amount of food. So it is easy to eat a lot of calories before you feel full. Fat and sugar increase the energy density of food.  Think of the last time you ate cookies or candy. Did you feel full after eating a “serving”?

Foods low in energy density provide few calories for a large amount of food. Fiber decreases the energy density of food because it is not fully digested. But the water content of food affects energy density the most.  Fruits and vegetables are naturally high in water and naturally filling.  Think of the last time you ate a banana.  Were you tempted to eat the whole bunch?

Even foods that are low in fat and sugar may be high in energy density if they contain little water.  These include processed snack foods like low-fat crackers and pretzels.  Next time you open a package, count out a serving size and see how much it fills you up. That is why you are seeing so many 100-calorie packages of these foods.  What you won’t see is a 100-calorie package of grapes or apples!

Why does energy density matter in thoughtful eating? Because we all feel more comfortable and satisfied with a certain volume of food each day. Not a certain amount of calories.  By adjusting the energy density of your diet, you can eat a larger, more satisfying volume of food and trust your body to tell you when you’ve had enough. The key is including some low-density foods with each meal or snack—like eating carrots with your pretzels or fruit with your cookies. In fact, that’s one big advantage of choosing Sargent Choice items.  To learn more see our 1+2+3 solutions section.