Have you ever noticed how certain foods seem to fill your stomach for a long time while others have you going back for a snack thirty minutes after you eat? It is not all in your head (or rather, your stomach)—this is due to something called energy density. According to the Mayo Clinic, “energy density is the number of calories (energy) in a specific amount of food. High energy density means that there are a lot of calories in a small amount of food. Low energy density means there are few calories in a large amount of food…Here's a quick example with raisins and grapes. Raisins have a high energy density—1 cup of raisins has about 480 calories. Grapes have a low energy density—1 cup of grapes has about 104 calories.”

The three main factors of energy density are water, fiber, and fat. “Fruits and vegetables generally have high water and fiber content, which provide volume and weight but not calories. That’s why they’re low-energy-dense foods.” Put simply, that means that fruits and veggies will fill you up but they do not have as many calories as other foods due to their higher water content. “Grapefruit, for example, is about 90% water. Half a grapefruit has just 64 calories.” The next item on the list, fiber, factors into energy density because “high-fiber foods not only provide volume but also take longer to digest, making you feel full longer on fewer calories. Vegetables, fruits, and whole grains all contain fiber. Popcorn is a good example of a high-volume, low-calorie whole grain. One cup of air-popped popcorn has about 30 calories.” Of course, that number does not factor in butter or any other toppings you might add to your popcorn before you watch a movie.

The last factor of energy density is fat, and “fat is high in energy density. One pat of butter, for example, contains almost the same number of calories as 2 cups of raw broccoli. Foods that contain fat naturally, such as various meats, or foods with added fats are higher in calories than are their leaner or lower fat counterparts.” This is why foods that are heavy in fat content or have a lot of oil do not necessarily fill you up, but they sit very heavily in your stomach. Of course, “some fats are healthier than others…Nuts, seeds, and oils, such as olive, flaxseed, and safflower oils, contain healthy fats.” Butter and shortening and other saturated or trans fats are significantly less healthy.

Knowing what we now know about energy density, how do we make this work for us in regards to our health and fitness goals? If you are looking to feel fuller for longer and avoid snacking, it could behoove you to focus more on consuming foods like fruits and vegetables as well as “choosing whole grain[s] over refined grains, including foods made with sugar or white flour.” For example, you could opt for whole wheat bread and pasta, oatmeal, or brown rice. However, as with most foods, it is important to keep an eye on portion sizes “because many carbohydrates are higher in energy density.”[1]

What are some of your favorite foods that keep you feeling full and help you resist the urge to snack at the vending machines? If you need inspiration, check out some of the recipes featured on this blog and tag us on social media to show us your culinary prowess!

[1] “The Simple Math That Helps You Feel Full on Fewer Calories.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 22 Mar. 2022, https://www.mayoclinic.org/healthy-lifestyle/weight-loss/in-depth/weight-loss/art-20044318#:~:text=High%2Dfiber%20foods%20not%20only,%2C%20low%2Dcalorie%20whole%20grain.