Is Glycogen Fat? How Glycogen Affects Your Health

Is Glycogen Fat? How Glycogen Affects Your Health

Every single thing you do on a daily basis requires energy. Whether it's breathing, working out, or chasing your kids around the yard, energy is used. 

This energy is calories, most of which come from the macronutrients we eat. These macronutrients are proteins, carbohydrates, and fats.

Now, with that being said, carbs and fats are your body’s main energy sources. On top of that, carbs are your body’s favorite energy source.

This is because they are the most readily available energy source! You see, our bodies are inherently lazy. It wants the most convenient thing, which in terms of energy is carbohydrates!

Now, there are a lot of different ways we can use carbohydrates. In fact, we can even store carbohydrates in the body for energy in the future. This is called glycogen.

But, does that mean glycogen is fat? Are glycogen and fat similar? Don't you worry ... This is what I'm here to talk about today!

What Is Glycogen? 

I know you’re probably thinking, "What the heck is glycogen?" I wondered the same thing too at one point. 

Well, glycogen is a form of glucose that is mainly stored in your liver and muscles. It's what fuels literally every energy-requiring process in your body ... Which as I mentioned above, is just about everything (1)!

Now, I know that takes us a step ahead and doesn’t explain where it comes from, so bear with me. I am getting there!

Where Does Glycogen Come From? 

Glycogen comes from glucose. Glucose comes from carbohydrates. Carbohydrates come from the foods that we eat and the drinks that we drink. 

So how do carbohydrates, glucose, and glycogen get used in the body? Well, all carbohydrates are broken down into glucose in your body.

Glucose is then used for any functions that our bodies need energy for immediately. After that, the leftover glucose is stored as glycogen in your body. This will make sure that you have quick energy if you are ever low on glucose at a given time. 

Your body can store about 15g per kg of bodyweight in glycogen to make sure you have energy when it’s needed (2). 

This can be by eating carbohydrates directly or by eating fats and protein. This means your body can actually make carbohydrates to store as glycogen in your body when necessary. This is a process called gluconeogenesis (3).

But let's get back to glycogen. Is glycogen fat? If it's stored in the body, that would mean it's fat, right?

Is Glycogen Fat? 

To be short and to the point, no, glycogen is not fat.

Glycogen isn’t fat. Glucose isn’t fat. Carbohydrates aren’t fat. 

I know that it’s common to hear that carbs are the devil and they’re going to make you fat, but that's not true. I’ll repeat that: carbs alone do NOT make you fat. 

Contrary to what you may have heard, body fat can only come from the overconsumption of calories.

With that being said, your body will use some glucose right away when you eat it. Extra glucose will be stored as glycogen throughout the body. After that, if there is still glucose left over, then it can be stored as fat. 

Now, your body can use fats for fuel too. However, it's much more efficient to use glucose or glycogen. So, how does your body burn glycogen and fat? Does it use glycogen first?

Burning Fat vs Burning Glycogen

I get it, most of us wouldn't mind burning a little body fat. I certainly wouldn't mind it! But, if your body prefers glucose and glycogen, does that mean it won't burn fat for energy?

Not exactly. So, let's talk about the difference between when your body will use fat vs when it will use glycogen. While yes, carbohydrates are the preferred fuel source for your body … Fats are used a lot too! 

When you use either one depends on the individual. However, there are some guidelines as well...

So, when do you use glycogen for fuel? During high-intensity exercise, your body will use muscle glycogen and glucose from your bloodstream (4). These are workouts like resistance training, long-duration cardio, and high-intensity cardio sessions.

But what about fat? When does the body use fat for fuel? Your body will use fats as its main energy source at rest and during low-intensity exercise (5). This can be things like your day-to-day activities and low-intensity workouts like walking.

One Last Word On Glycogen

At the end of the day, our bodies need energy. Both glycogen and fat can be an energy source for your body. However, is glycogen fat? No.

This topic can get pretty in-depth and I know that if you aren’t a super sciency person like I am, then it can be easy to get lost.

If your goal is weight loss, trust me, you don't have to worry about glycogen. In fact, you realistically don't even have to worry about when your body is using fat or glycogen.

At the end of the day, weight loss comes down to calories in vs calories out. To lose weight, you need to consume less calories than you burn. To gain weight, you need to consume more calories than you burn.

I know all of this can be a little confusing, which is why we're here to help. Whether it's your nutrition, workouts, recovery, or anything in between ... We have the answers and resources you need.

That's actually why we developed the 1st Phorm App, which is the ultimate all-in-one tool for your health and fitness. Inside the app, you'll get access to:

• A certified personal trainer and nutrition coach (sometimes a dietitian) to coach you every day in the app

• A custom nutrition plan and an easy way to log your food to stay on track

• Custom workout programs geared toward your goals

• 5x per week live streams about nutrition, training, and supplementation

• Activity and step-counting software

• Progress tracking and body metrics to make sure you get the results you're after

...and so much more! If you're ready to take your health and fitness to the next level, download the 1st Phorm App today!

In the meantime, don't hesitate to reach out with any questions you may have! We have a full team of NASM Certified Personal Trainers and Nutrition Coaches right here in St. Louis, Missouri. Just give us a call at 1-800-409-9732 or send us an email at any day from 6 AM to 10 PM Central.

Download the 1st Phorm App


(1) Hantzidiamantis , Paris J., et al. “Physiology, Glucose.” StatPearls, StatPearls Publishing, 30 April 2024.

(2) Acheson, K J et al. “Glycogen storage capacity and de novo lipogenesis during massive carbohydrate overfeeding in man.” The American journal of clinical nutrition vol. 48,2 (1988): 240-7. doi:10.1093/ajcn/48.2.240

(3) Hantzidiamantis PJ, Awosika AO, Lappin SL. Physiology, Glucose. [Updated 2024 Apr 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from:

(4) Bjorntorp, P. “Importance of fat as a support nutrient for energy: metabolism of athletes.” Journal of sports sciences vol. 9 Spec No (1991): 71-6. doi:10.1080/02640419108729867

(5) Patel PN, Zwibel H. Physiology, Exercise. [Updated 2022 Sep 12]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from:


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