Calorie density is typically stated as calories per gram volume of food. Calorie sparse foods contain few calories for a relatively large amount of food, while calorie-dense foods contain a lot of calories for a relatively small amount of food. For example, 100 grams of grapes contains a mere 15 calories, meaning that it’s calorie density is 0.15 calories per gram. Raisins, on the other hand contain a whopping 716 calories per 100 grams, or 7.16 calories per gram. So we can say that grapes is calorie-sparse, while raisins are calorie-dense. Phew! That was way too much science, let's break that down.
In a more basic formula, foods with more 0-calorie elements tend to be better choices to help fill you up and feel more satisfied. Some of the best 0-calorie elements to base your choices off of are: water, fiber, and protein. Grapes for example are the water-filled version of raisins! They will fill your stomach with a larger amount of 0-calorie volume than raisins will. This concept can also be applied to steak vs jerky, or baked potato vs potato chips.
We know that in order to lose body fat, you need to be in a caloric deficit. Which is where choosing higher-volume, calorie-sparse foods comes in. But that’s not to say that eating for volume will make being in a prolonged deficit pleasant – because it won’t. Nor will it completely relieve you of hunger, as the mechanisms that regulate hunger are more complex than that. Enough that we can’t completely override them just by putting more water and fiber in your stomach...
Having said that, eating larger volumes of calorie-sparse foods rather than smaller quantities of calorie-dense foods might take the edge off the hunger enough that you may find it easier to adhere to your diet plan or targets. And since adherence is the number one factor in your success, anything we can do to nudge the odds in that direction is a WIN!
Though we know foods rich in water typically have low caloric density, it's not always obvious which foods those are (though watermelon is pretty obvious). That's why we've created these easy to view categories, classifying food as red, yellow or green.
Green foods have the lowest caloric density and/or the highest concentration of healthy nutrients. Think: veggies and whole grains.
Yellow foods have a mid-level caloric density and/or a medium amount of healthy nutrients. Think: lean meats and starches.
Red foods have the highest caloric density, are the most calorie-dense and/or have the least healthy nutrients. Think: red meats and desserts.
FYI - In no way, shape, or form are we saying here that Macadamia nuts are worse for you than the Snickers bar right above it! Nuts are an extremely nutritious form of protein and healthy fats. They are an extremely helpful source of fuel to have on a hike since they are small, light to carry, and extremely high in caloric density. No foods are ruled out as 'Bad' or 'Good' when measuring your diet by caloric density. It is simply about understanding PORTION CONTROL, and what items would best satisfy a hungry stomach with the least calories! So go for it, have a bite of that Snickers bar if you want to! But split the rest with your hubby or kiddos, you know they want some too :)
To Wrap Things Up
We know you're a human being, not a rabbit, which means that you don't want to eat only salads. Most of your diet won't be green foods -- and that's fine. We want you to eat healthy for the rest of your life -- giving up desserts forever is neither sustainable nor as yummy. We recommend that you eat the following breakdown:
Green foods: 30%
Yellow foods: 45%
Red foods: 25%
For example, if you’re dieting, you could make the least calorie-dense foods (e.g., fruits and vegetables) the foundation of your diet. Then add enough protein for your body weight and goals (with some wiggle room for preference), choosing higher-volume proteins if that’s what you want. Add enough starchy foods to fuel your training and to feel good (again, with some wiggle room for preference), choosing higher-volume starches if that’s what you want. And then add a little bit of fat.