Do Calories Matter? Understanding the Science of Fat Loss

^{Written By Kris Einboden, GM and Professional Coach at The Six Pack Dad Tribe}

Calories, calories, calories.

That's all you hear when it comes to fat loss, and for good reason.

Calories are what, at a fundamental level, determine whether we gain or lose body fat.

Eat more calories than your body needs each day, and you'll create a calorie surplus. Over time, your body stores that excess energy, resulting in weight gain.

Eat fewer calories than your body needs each day, and your body will use stored energy, including body fat, to make up the difference, resulting in fat loss.

Many people hear this and think, "Time to diet and exercise," which isn't necessarily wrong. There's just more to the story than that.

A positive or negative calorie balance, also known as a calorie surplus or a calorie deficit, is determined by a myriad of different variables.

Calories in = the food and drinks you consume.

Calories out, in no particular order, =

1. The energy it takes to digest food.
2. The energy it takes to keep you alive (aka your metabolism).
3. The energy it takes to complete daily tasks.
4. Purposeful exercise.

Let's break these down individually.

Calories In: What You Eat

Calories in are determined by the food and drinks you consume. The fat stored in your body ultimately comes from the food you eat. You kind of are what you eat.

But here's something interesting: no food is automatically or preferentially stored as body fat simply because of what it is.

I repeat, no food is automatically stored as fat just because it's a particular type of food.

Yes, indeed, the sugary soda you drank last week didn't immediately go straight into your fat cells.

Now, how can this be true?

Well, again, it's all about calorie balance. You can't store fat unless you eat more than you burn. Studies have demonstrated that even when people eat diets made up almost entirely of sugar, they can still lose fat if they consume fewer calories than their bodies need.

Crazy, right?

Now, don't go attempting a sugar-only diet in an effort to lose weight. There are plenty of problems with a diet like that, including micronutrient and macronutrient deficiencies. However, it serves as an example of an important point: fat loss is heavily influenced by how much you eat, not simply what you eat.

That doesn't mean food quality is irrelevant. The foods you eat influence your hunger, fullness, energy levels, nutrient intake, and ability to stick to a calorie deficit. This is why the quality of your diet still matters tremendously.

Calories Out: The Four Ways Your Body Burns Energy

Calories can be burned in various ways, all of which contribute to our overall calorie balance.

1. Resting Metabolic Rate: The Energy It Takes to Keep You Alive

First, the majority of calories burned on a daily basis come from our resting metabolism.

People talk a lot about metabolism, but what even is it?

Our metabolism refers to the chemical processes that keep our bodies functioning. Your heart, brain, and other organs need energy to operate so that your body can keep everything running and maintain the functions necessary to keep you alive.

Even when you're sitting at your desk, watching television, or sleeping, your body is constantly burning calories.

In fact, your resting metabolic rate accounts for the largest portion of your daily calorie expenditure.

2. Thermic Effect of Food: The Energy It Takes to Digest Food

Second, calories are burned through digestion.

It takes energy to break down food, absorb nutrients, and move everything through our digestive system.

Not all foods are created equal, however. Some foods, such as protein-rich foods and fiber-rich foods like fruits, whole grains, and vegetables, have what's called a higher thermic effect, which is fancy science lingo for saying it takes more energy to digest and process these foods.

Thus, when you consume more of these kinds of foods, you naturally burn more calories just through digestion. Quite the "hack." 

3. Non-Exercise Activity Thermogenesis (NEAT): The Calories You Burn Throughout the Day

Third, we burn calories just by doing everyday tasks such as walking, cleaning, fidgeting, standing, and even playing with our kids.

This is called non-exercise activity thermogenesis, or "NEAT," in the scientific literature.

NEAT is particularly important because it can account for a significant amount of your daily calorie expenditure, depending on how active you are throughout the day.

You could spend an hour at the gym every morning, but what happens during the other 15 hours you're awake?

If you spend most of your workday sitting at a desk, drive everywhere, and spend your evenings on the couch, your overall daily movement might be much lower than you realize.

NEAT can be increased relatively easily by getting more steps.

I recommend finding a baseline of how many steps you currently get each day and then gradually working toward 7,000–10,000 steps per day.

You will likely be surprised by how few steps you actually get, especially if you work a desk job.

Why 7,000–10,000 steps?

This is a practical target for many people because it can meaningfully increase daily activity without demanding excessive time or effort. It's not a magic number, and you don't necessarily need to hit it every day to make progress.

Most people can work toward this goal by going on a couple of longer walks and simply making an effort to move more throughout the day. Park farther away at the grocery store, get up periodically from your desk, take phone calls while walking, or go for an evening walk with your family.

4. Purposeful Exercise: Cardio and Resistance Training

Fourth, we can burn energy through purposeful exercise.

This is probably the form of calorie expenditure you're most familiar with. When we work hard by lifting weights, running, cycling, or swimming, we force our muscles to use energy to fuel that activity.

Purposeful exercise makes up a smaller percentage of total daily calorie expenditure for many people, but it's highly controllable. We dictate how much time and effort we put into it and, to some extent, how many calories it contributes to our overall expenditure.

There are two primary ways we can increase our physical activity expenditure: cardiovascular training and resistance training.

Cardio exercise tends to burn more calories during a typical workout than resistance training. However, resistance training plays a particularly important role in maintaining and building muscle.

When you're in a calorie deficit, your body can lose both fat and muscle. Resistance training helps preserve that muscle, allowing you to improve your body composition as you lose weight.

There is also some additional energy expenditure involved in recovering from a lifting workout, but the bigger benefit of resistance training is maintaining muscle mass and strength while losing body fat.

This is why I recommend combining cardio and resistance training rather than relying exclusively on one or the other.

Putting It All Together

So, what does all of this actually mean for you?

If your goal is to lose body fat, you need to create a calorie deficit. That's the foundation. But as we've discussed, there are several ways to influence how many calories you burn each day and make that deficit easier to maintain.

Here's where I'd start:

1. Get your protein intake where it needs to be.

Prioritize protein at every meal. Build your meals around quality protein sources like chicken, beef, fish, eggs, Greek yogurt, and other lean meats. This helps you maintain muscle while losing fat, supports recovery, and keeps you feeling fuller throughout the day.

2. Increase your daily movement.

Don't rely exclusively on your workouts to burn calories. Find out how many steps you're currently getting and gradually work toward 7,000–10,000 per day. Take walking calls, get up from your desk, park farther away, and make evening walks with your family part of your routine.

3. Lift weights consistently.

Aim for 2–3 resistance training sessions per week, depending on your schedule and experience. Your goal isn't just to weigh less. It's to lose body fat while maintaining or building muscle. That's what helps you look, feel, and perform better as you lose weight.

4. Incorporate cardiovascular exercise.

Cardio is great for your heart, overall fitness, and increasing your energy expenditure. You don't need to spend hours on a treadmill. A few short 15-minute sessions each week, combined with your daily walking, can go a long way.

5. Eat in a way you can actually sustain.

You don't need to eliminate carbohydrates, avoid eating out, or follow an overly restrictive meal plan. You need to understand your nutritional needs, build balanced meals, manage portions, and develop habits that work with your lifestyle.

And this last point is probably the most important.

You can understand every principle in this article and still struggle to put it into practice.

Maybe you travel frequently for work. Maybe your calendar is packed with meetings, your kids have activities every evening, or you're constantly eating at restaurants. You know what you should be doing, but actually following through is another story.

This is where we do things differently at The Six Pack Dad Tribe.

We help busy professional dads take the science of fat loss and turn it into a practical, personalized system they can follow in real life.

That means building a nutrition strategy around your actual schedule, helping you make better food choices at home and when eating out, creating an efficient exercise routine that doesn't require hours in the gym, and developing the daily habits that keep you progressing even when life gets busy.

You get individualized coaching, accountability, and a framework that evolves with you as your body and goals change.

Take our 2 min Dad Health Quiz to assess your health, fitness, and habits. Find out where you stand and what you can improve: Click Here To Take The Dad Health Quiz