All About Calorie Density

posted in: All Posts, Nutrition | 4

Though the foods in the picture above may appear to be unrelated at first glance, they share a common trait. Can you guess what that is? The answer is that each of the servings pictured above provides 100 calories. As you may have noticed, some of these provide much more food for the same number of calories. These foods have a lower calorie density than the others.

What Is Calorie Density?

Calorie density is the number of calories provided by a certain amount of food, and is typically stated in terms of calories per gram. For example, 100 grams of cucumber contains a mere 15 calories, or 0.15 calories per gram. Macadamia nuts, on the other hand contain a whopping 716 calories per 100 grams, or 7.16 calories per gram.

Accordingly, we can say that cucumber is calorie-sparse, while macadamia nuts are calorie-dense. Calorie-sparse foods are usually higher in water and fiber content, and lower in fat than calorie-dense foods. Conversely, calorie-dense foods are usually drier and higher in fat.

An example of how water content impacts calorie density can be seen when comparing dried fruit to fresh fruit. When comparing equal weights of each, raisins are much more calorie-dense than grapes. Similarly, an example of how fat content impacts calorie density can be seen when comparing different cuts of beef. When comparing equal weights of each, fatty cuts of beef are more calorie-dense than lean cuts of beef.


Why Calorie Density Matters

Though calorie density can be an important consideration for anyone, it becomes even more relevant when trying to gain or lose weight. The reason ultimately comes down to hunger and satiety signals, and how each of these impacts our goals.

CALORIE DENSITY AND WEIGHT LOSS

We know that if we want to lose body fat, we need to be in a caloric deficit. In other words, we need to eat fewer calories than we expend. Unfortunately, eating fewer calories will probably leave us hungry from time to time. And when we’re hungry, we’re more likely to respond by overeating.

From that perspective, managing hunger is an essential piece of the fat loss puzzle. That’s where choosing higher-volume, calorie-sparse foods comes in. It’s not a panacea, as the mechanisms that regulate hunger are complex. Still, it may help.

CALORIE DENSITY AND WEIGHT GAIN

Calorie density can also be an important consideration when you’re trying to gain lean body mass. To gain weight, we need to be in a caloric surplus. In other words, we need to eat more calories than we expend. Unfortunately, a surplus can require an awful lot of food — sometimes more food than a person can comfortably eat in a day.

Do you consider yourself a hard-gainer? You may want to look at the calorie density of your diet. Are you eating a ton of calorie-sparse foods like fruits and vegetables? While fruits and vegetables are wonderful, you may be filling up with so much volume that you can’t realistically get in enough calories.

Similarly, have you been able to put on weight but you feel uncomfortably full all the time? If so, swapping out some calorie-sparse foods for those that provide considerably more calories for less bulk may help.


Calorie-Dense Foods Are Not Bad

I want to take a moment to emphasize that while incorporating more foods with a lower calorie density in your diet may help with satiety, or even potentially supply more micronutrients, this does not mean that you shouldn’t ever eat calorie-dense foods.

Just because a food is calorie-dense does not automatically mean that it’s a “bad” food. Because, really, there are no “good” or “bad” foods. Calorie-dense foods simply contain more calories per gram. Additionally, while some calorie-dense foods may not provide much nutrition, plenty of calorie-dense foods are extremely nutrient-dense (many of them more so than calorie-sparse foods).

To frame it differently, when the goal is weight gain or loss, it may help to think of total daily calories as a budget. Whether you want to gain, lose or maintain weight, you have a set budget (or calorie allotment) that will allow you to achieve your goal. What you do with that budget is up to you.

Some people are volume eaters. I fall into this camp. Volume eaters prefer eating larger quantities of lower-calorie foods. Other people would rather enjoy small quantities of richer, higher-calorie foods. It’s up to you to decide the ratio of low-calorie foods to high-calorie foods that keeps you both mentally and physically satisfied, while also keeping you reasonably close to your calorie budget.


Calorie Density and Macronutrients

Below I’m going to show you some visual comparisons of what 100 calories worth of various foods looks like. First, though, I’d like to clarify that the portions pictured are not suggested serving sizes. Your own serving size is ultimately up to you, and doesn’t necessarily need to be limited to a 100-calorie portion. The foods were only standardized to 100-calorie portions to make for an easy illustration of how they differ in volume for the same number of calories.

In addition, I’ve divided the photos into groups of similar foods to make for a more accurate comparison. But it’s not perfect. While some foods do fit neatly into one category, most have a bit of overlap since foods rarely contain only one macronutrient. Still, I tried to represent everything as consistently as I knew how.

Proteins

Protein provides 4 calories per gram. It is reported to be the most satiating of the macronutrients. So, getting enough protein with each meal may help you feel fuller longer. You may need to experiment to figure out how much protein per meal feels best for you. As a general rule of thumb, around 20 to 30 grams per meal is a great place to start.

Protein sources vary in calorie density primarily because of their fat content. The leaner the protein source, the more protein “bang for your buck” you’ll get. Two similarly lean sources of protein usually have roughly comparable calories.

For example, 93% lean beef and 93% lean turkey are very similar in calories. Similarly, 97% lean ground beef and 97% lean ground turkey are also similar in calories, but they both contain less calories than the 93% lean versions. As you can see below, you get more food volume for the same number of calories when you choose 93% ground beef over 85% ground beef.

Some proteins vary in calorie density because of their water content. Beef jerky is a good example. The process of drying the meat and removing the water makes the end product more calorie-dense. The hot dog pictured below illustrates both of these points. It’s been processed to remove quite a bit of water, plus it has a relatively high fat content. As a result, it’s more calorie-dense than the plain meats pictured.

A NOTE ON HOW THESE WERE MEASURED

Since most of these proteins are eaten cooked, I took the cooked weight and used the corresponding USDA nutrition data for the food after cooking. Here are some examples:

  • USDA 15237 – Fish, salmon, atlantic, farmed, cooked, dry heat
  • USDA 23476 – Beef, ground, 93% lean / 7% fat, crumbles, cooked, pan-browned

These values take into account the water loss and subsequent increase in calorie density that typically occurs with specific types of cooking. They may not be quite as accurate as using raw weight with raw nutrition data, but they’re surprisingly close in most cases, and they make measurements easier.

I did it this way to give a more realistic visual representation of volume by comparing each food in the state in which we’d most likely be eating it. If you’d like to see more details on which USDA database items correspond with each of these photos, please visit this Google spreadsheet.

Carbohydrates

Carbohydrates provide 4 calories per gram. Some carbohydrate-rich foods are more filling than others. You’ll likely find that the more fiber and water a carbohydrate-rich food provides, the more filling it tends to be. For example, I find low-calorie fibrous vegetables to be very satiating.

When comparing fruits and vegetables, fresh fruit tends to be more satisfying than dried fruit. The graphic below illustrates the difference in volume between a fresh fruit such as grapes and their dried counterparts, raisins.

Similarly, where vegetables are concerned, the ones with a higher water content, such as the spaghetti squash pictured below, will likely be more satisfying than an isocaloric amount of a drier and more calorie-dense version, such as corn or peas.

Where grains and starches are concerned, water and fiber content contribute greatly to satiety as well. Starchy vegetables that contain a lot of water and fiber, such as potatoes and winter squash, tend to be quite satisfying. With grains, you may find that fiber and water-rich options, such as cooked oatmeal, are more filling than drier grains like bread, pasta or rice.

An additional factor that we can consider when discussing calorie density is how much air a food contains. Take rice cakes, for instance. Even though rice cakes can mathematically be classified as calorie-dense by weight alone, they are so full of air that they actually provide significantly more volume than their calorie density implies. As you can see below, a mere 26 grams of rice cakes provides a surprisingly large volume of food.

A NOTE ON HOW THESE WERE MEASURED

For the foods that are typically eaten cooked (such as many of the vegetables, pasta, rice, potatoes, squash, etc.) I took the cooked weight and used the corresponding USDA nutrition data for the food after cooking. Here are some examples:

  • USDA 11091 – Broccoli, cooked, boiled, drained, without salt
  • USDA 20121 – Pasta, cooked, enriched, without added salt

These values take into account the water loss and subsequent increase in calorie density that typically occurs with specific types of cooking. They may not be quite as accurate as using raw weight with raw nutrition data, but they’re surprisingly close in most cases, and they make measurements easier.

I did it this way to give a more realistic visual representation of volume by comparing each food in the state in which we’d most likely be eating it. If you’d like to see more details on which USDA database items correspond with each of these photos, please visit this Google spreadsheet.

Fats

Fat provides 9 calories per gram, meaning that pure fats, such as oils, have the highest calorie density out there. Again, this doesn’t mean that fat is inherently good or bad. In fact, consuming enough dietary fat is important for health. Some people find fat to be very satiating. Personally, I don’t find that fat gives me as much satiety as protein or complex carbohydrates, but your mileage may vary.

Since fat provides just over double the calories per gram than proteins or carbohydrates, fatty foods make it easy to exceed your daily calorie budget before you know it. So enjoy some dietary fat, especially those from high-quality sources, but use moderation so that your total caloric intake stays in line with your goal.

Similar sources of fat provide roughly comparable calories. For example, different oils (such as olive oil, peanut oil and coconut oil) are similar in calories. Different nuts are also similar in calories to each other, but lower in total calories than oils.

This is because nuts don’t provide just fat. They also provide some carbohydrate and protein, which are both lower in calories per gram than pure fat. As a result, nuts have slightly fewer calories than pure fats such as oils. This mix of macronutrients is also why plant fat sources, such as olives and avocados, are even less calorie-dense than either nuts or oils.

Sweets and Snack Foods

Another factor that can affect calorie density, especially in the case sweets and snack foods, is how processed a food is. Not that there’s anything inherently wrong with processing food. (In fact, almost everything we eat has been processed to some extent.) But the more processed a food is, the less air, water and fiber it tends to contain. Additionally, fat is typically added, which is more calorie-dense than carbohydrate or protein alone. Therefore, the final product may be more calorie-dense than its constituents.

When looking at the popcorn in the graphic below, we can see another example of how air content affects food volume. Even though the popcorn is assigned a middle-of-the-road calorie density by weight, we can clearly see that it provides far more volume than anything else in the picture.

Conclusion

In conclusion, calorie density gives us a way to compare the number of calories contained within a fixed weight of different foods. It’s important to understand that calorie density is not an assessment of foods that you should or shouldn’t eat. It simply helps us identify foods that might be more filling for less calories.

If your goal is to lose fat, you may have an easier time reducing your daily caloric intake by replacing some calorie-dense foods with more calorie-sparse options. By doing this, you may be able to feel more satisfied for less calories.

If your goal is to gain weight but you haven’t been successful (or if you’re currently eating a surplus of calories, but you’re experiencing gastrointestinal distress) you may be able to more easily increase your calorie intake by favoring more calorie-dense foods in place of some of your calorie-sparse foods.

If you’d like to learn more about the calorie density of the foods pictured here, please visit the spreadsheet with the full data. There you’ll find the total calories, grams of each macronutrient, calorie density, typical serving size, and calories per serving for each of the foods above. If you have any questions, please feel free to leave them in the comments.

4 Responses

  1. Patrick
    | Reply

    I am a visual learner and this is wonderful. Best I have seen. Thank You!

    • Christy Shaw
      | Reply

      Patrick, thank you so much for the feedback! I’m so glad it helped.

  2. Mary
    | Reply

    Great explanation with handy charts. Excellent information. Thank you.

    • Christy Shaw
      | Reply

      Thank you Mary!

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