Calories 101

Karina Nwoko, MS, RD, LDN

When it comes to understanding how to fuel our bodies, it is important to fully grasp what a calorie is. Calories are simply a unit used to measure energy in food. If you think of our body as a light bulb, calories are the watts we use to stay lit. They are NOT a nutrient/substance found in food, but certain nutrients can yield us energy (calories) when we metabolize them.

They are:

• Carbohydrates: 4 calories/gram
• Proteins: 4 calories/gram
• Fats: 9 calories/gram
• Alcohol: 7 calories/gram

Vitamins and minerals do not provide us with calories but we get these essential nutrients by consuming foods/drinks that will have calories due to their macronutrient content.

You may have heard the phrase “a calorie is a calorie”. In a sense this is true – no matter if you over ate Popeyes or parsnips, no matter if you over ate carbohydrates or protein, when you eat or drink in excess, your body will then have an excess of energy (calories). Our body can store this in fat – our back-up battery! It can then tap into this energy source when energy is scarce.

But in another sense “a calorie is a calorie” is an oversimplfied saying. When we are working on optimizing performance, weight loss or other goals, we have to be aware of not only our calories but the nutrient density of those calories. For example, 2 medium kiwis and 12 gummy bears have around 100 calories each. But the kiwis are high in certain nutrients including fiber, vitamin C, vitamin K, and potassium – therefore they are nutrient dense. The kiwis also provide more volume and will likely keep you fuller for longer than 12 gummy bears. The gummy bears on the other hand do not provide any additional nutrients other than their calories coming from added sugar. They are classified as having a low nutrient density.

Am I saying we should avoid gummy worms altogether? Absolutely not! In fact they can be a great source of easily digestible carbohydrates for those in endurance sports. And they are fun to eat! The point I am trying to make is that we must be more mindful of the sources of the calories we consume and determine what their purpose is in our overall day in regards to our current goals.

How many calories do you need in a day? It depends on so many things. What are your goals? Fat loss? Muscle gain? Weight maintenance? There are many equations out there to give you estimates (Harris Benedict equation, Mifflin St. Jeor are two popular ones) but I recommend meeting with a dietitian or a qualified/experienced coach if you are serious about tracking calories for your health goals for a more personalized approach.