Is It All About Calories In Calories Out?

There’s a ton of advice out there for how to lose, gain, and maintain weight. However, one of the most common methods you see is ‘calories in calories out.’ 

What does that mean exactly, and is it really that simple? We’re breaking it all down in this article.

What is ‘Calories In Calories Out?’

Calories in calories out (CICO) is referring to energy balance, or the number of calories you’re consuming vs. the number you’re burning. 

You consume calories through food and drink, but your body burns calories in a few ways: 

  1. Physical activity - The calories you burn with exercise make up 10 to 30 percent of the calories you burn.
  2. Digestion - This accounts for about 10 percent of your daily calorie burn.
  3. Metabolism - The normal, everyday functions of your body burn about 65-80 percent of your total ‘calories out’ every day. This is also called your Resting Metabolic Rate (RMR).

Everyone wants the magical answer to weight management and fat loss. CICO seems to be as close as we can get. Following this method gives you numbers that make sense and a more solid sense of control than you get with some other more trendy diets.

The other attractive thing about CICO is flexibility. It’s more challenging to sustain a diet that restricts certain foods, such as keto, Paleo, or plant-based.

Focusing on energy balance makes it a little easier to adapt your diet to your lifestyle and preferences, which may make it more sustainable. 

How do I Know How Many Calories to Eat?

Depending on your goals, your calorie goal will be one of three things:

  1. Deficit
  2. Balance
  3. Surplus

To lose fat, your goal will be a calorie deficit. This just means that you’re burning more calories than you consume. 

To maintain your weight, you want the calories you consume and burn to balance as much as possible. 

To gain weight, your goal is a calorie surplus. In other words, you’re consuming more calories than you burn. This applies to gaining muscle as well. You need the extra calories to build muscle.

Obviously, we could go a lot deeper here into how each of these work, but those are the basics. For all three, you have to pay attention to the balance between your ‘calories in’ and ‘calories out.’

How do I Increase Calories Out?

If you want to lose weight, your goal is most likely fat loss, and therefore calorie deficit. We know that one way to achieve a calorie deficit is to consume fewer calories (eat less). However, that’s not the only way. 


You have the most control over ‘calories out’ through exercise. The longer or more intense a workout, the more calories you will burn. 

Certain types of workouts, like high-intensity interval training (HIIT) have been shown to burn more calories post-workout

Boosting Metabolism 

Remember, the majority of your ‘calories out’ come from your metabolism. “Metabolism” refers to all of the cellular processes in the body. The majority of this is out of your control, but you can improve it slightly. 

One way is through diet. Some research suggests that eating a high protein diet may increase metabolism slightly. 

Other things like drinking coffee, green tea, cold water, and eating spicy foods can temporarily “boost” your metabolism as well. 

Second, you can influence your metabolism by changing your body composition. You’ve probably heard something along the lines of “muscle burns more than fat,” and it’s true. Muscle requires more metabolic activity.

To add more muscle mass, incorporate weight training (like this full-body dumbbell workout) and make sure you’re eating enough protein to support muscle gain.

It’s vital that you’re eating enough. It’s tempting to cut as many calories as possible to achieve a larger deficit and lose fat more quickly, but this can actually backfire. If your body is calorie-deprived, your metabolism will accommodate to preserve energy. In other words, your metabolism slows.

Finally, get some sleep. Studies have shown a link between lack of sleep and disrupted metabolism and weight gain.

Can I Eat Anything I Want as Long as I'm in a Calorie Deficit?

Ah, the common question. If the goal is a calorie deficit, does what you’re eating need to be healthy? 

That depends on your goals. If all you care about is fat loss and/or seeing the number on the scale go down, then technically yes. 

However, if your overall health is a priority (and it should be), keep reading. 

Nutrition is About More Than Just Calories

Remember, food is fuel. If you want to give your body the highest quality fuel, you have to focus on macronutrients - carbs, protein, and fat. 

How you balance those macronutrients in your diet makes a big impact on not only your goals, but your overall health. If you simply focus on calories and ignore these major building blocks of what you’re actually eating, you can worsen your health even if you’re technically losing weight. 

The micronutrients, vitamins, and minerals, and fiber matter too. These support literally every process in the body. They keep the immune system functioning, protect your cells from damage, and keep the good bacteria in your gut thriving.

They help your cells produce energy and get important things into the cell, like oxygen and glucose. 

Ignoring Nutrition Comes with Risks

The food you eat affects a lot more than just your weight. Only focusing on calories and eating whatever you want will probably do more harm than good, even if you’re a “healthier” weight.

Junk is usually full of saturated fat, salt and sugar. If your diet is heavy in these foods, your heart health will likely suffer. Your blood lipids will become out of whack, and you could develop chronic inflammation.

In your gut, these foods feed harmful bacteria and create imbalance. The obvious effect here is digestive issues, but poor gut health is detrimental to the entire body. Your immune system won’t work as well, your mood will be off, it will be harder to lose or maintain weight, and your skin could even suffer. 

All of these factors increase your risk for chronic disease, regardless of your weight. Fat loss is a great step to better health, but you also have to be intentional about the food you choose.  

The Takeaway

Calories in calories out is a great method for sustainable fat loss, but not a loophole to ignore the quality of your diet. 

It’s true that a calorie deficit could facilitate fat loss even if you’re eating junk, but it’s important to remember that weight loss doesn’t always indicate health. You have to consider how being careless with your diet can affect inflammation, gut health, heart health, and other pieces of your wellbeing. 

If you want to lose fat, CICO can simplify the process. However, to do it right, fueling your body with nutrient-dense foods while being intentional with macros is a must.