How Does The Body Burn Fat? Discover Exactly What It Takes To Lose Fat Fast

how does the body burn fat

How Does The Body Burn Fat? Discover Exactly What It Takes To Lose Fat Fast

Your body burns fat because it needs energy.

But how does it work?

How does the body burn fat, so it can get that stored energy off your body?

Understand the HOW, and you solve the mystery of losing weight and getting fit.

How Does The Body Burn Fat Faster [Simplified]

Why Your Body Stores Fat

Body Fat.

Anatomists call it the body’s natural insulator; a warm coat that’s literally built out of burnable fuel.

Without body fat, you couldn’t survive.

But do you really need all of your insulation?

If you were a house, would you have the highest R-value?

Yes, some body fat has its perks, but all you see when you look in the mirror is ripples, bumps, and bulges.

The problem with burning fat

It’s not as easy to remove your fatty coat as it was to put it on.

You can’t unzip it and drop it to the floor like a warm winter jacket.

You’ve been trying to lose weight for months (maybe years) with little or no success.

  • You drag yourself to the gym.
  • You order the salad when you’d rather have the fries.
  • You sacrifice your temporary happiness for the ultimate goal…living your life free from extra pounds.

So why hasn’t the scale reflected your efforts?

You’re missing something.

If you’re not eating or exercising in a way that forces your body to tap into its fat reserves, you’ll be a sugar burner, not a fat burner.

In this article, you’ll learn how to shift your weight loss into high gear as we answer the questions, “How does the body burn fat?”

Are All Calories The Same?

There are only three nutrients that have calories:

  • Carbohydrates
  • Proteins
  • Fats

Calories provide energy.

Fats give you the most energy; providing 9 calories per gram.

Carbs and proteins both contain 4 calories per gram.

The other three nutrients: vitamins, minerals, and water are calorie-free, but you need them to convert calories into energy – that’s what metabolism is all about.


There is a common saying that floats around, which implies that all calories are created equal…“A calorie is just a calorie.”

Umm, yeah…well, uh…it’s not quite that simple.

You can lose weight if you eat only french fries, only lettuce, or only chicken as long as you’re eating a very low-calorie diet.

But once those calories are inside your belly, your body is going to handle them in wildly different ways.

Digestive enzymes break down calorie-containing foods:

  • Carbs become sugar
  • Proteins become amino acids
  • Fats become fatty acids

Blood carries these digested nutrients to your body cells.

Amino acids are important little building blocks for all types of body tissues, so your body doesn’t like to burn them for fuel. They become enzymes, hormones, and muscles.

Sugar is the quick energy source, so it’s your body’s favorite. It can be burned right away or stored as energy in your liver, muscles or fat cells.

Fatty acids recombine into triglycerides and get tucked away in your fat cells as a long-term energy source.

Why Does The Body Burn Fat?

Your body burns fat when there’s no immediate energy available. It’s kind of like going to the bank when your wallet is empty.

There is an order that your body follows to get energy:

  1. Glucose (a.k.a. sugar) in your blood is immediate energy; it’s the cash in your wallet.
  2. Glycogen is stored glucose in your liver and muscles, it’s easy to access, but there’s not much there. Think of glycogen as the money in your checking account.
  3. Body Fat is an efficient way to store energy, but the least accessible; think of body fat as the savings in your retirement account.
  4. Muscle tissue can be burned as a last-ditch effort to get energy. If you’re starving or losing weight too quickly, your body starts burning muscle. Think of burning muscle as going into debt to pay your bills.

Understanding this order of energy-burning shows us that there are ways to manipulate the foods you eat and the ways you exercise to burn fat faster. I’ll share those with you later in this post.


Keeping Blood Glucose Levels Steady

Your blood is very picky about how much glucose it wants in your bloodstream; not too much, and not too little.

If your blood glucose level gets too high, insulin comes in and carries it off to your body cells for storage.

If your blood glucose level gets too low, glycogen from your muscle and liver cells is broken down to fill up the blood with glucose.

When glucose and glycogen stores are gone, your liver can make glucose (gluconeogenesis), or burn body fat for energy.

How Does The Body Burn Fat?

When your body is ready to burn fat, it turns into a living chemistry lab.

I like to think of fat-burning (a.k.a. fat metabolism) as a play, so let me set the stage…



  • Triglyceride (stored fat)


  • Insulin (a hormone that tells the fat cells to stop burning fat)
  • Glucagon (a hormone that tells the fat cells to start burning fat)
  • Lipase (an enzyme that initially breaks up the triglyceride)
  • Coenzyme A ( a helper)
  • ATP (ATP is energy; it takes energy to make energy out of fat)
  • Assorted molecules (these are the extras, including water, NAD+, FAD+, and many others. They don’t have glamorous jobs, but without them, the play could not go on.)


Triglyceride wants to change. He’s tired of hoarding energy and wants to split up to share his energy with the rest of the body.


The play opens inside your body. It’s been a few hours since you’ve eaten and your blood is low on glucose.


Without this quick energy source, your body will soon grow fatigued; it’s time to tap into your fat cells.

SCENE 1: Levels of the hormone glucagon are rising in your blood. It’s been attracted here because of the low glucose and insulin levels.

SCENE 2: The hormone changes in the blood tell the enzyme lipase to go to your fat cells and break the bonds that hold the triglyceride together.

SCENE 3: As the triglyceride breaks apart, its fatty acids are released into the blood where they are shuttled to body cells that contain “powerhouses” called mitochondria.


Act 2 opens inside the body cell as the fatty acid encounters a character named Coenzyme A, or CoA for short.

SCENE 1: CoA and the fatty acid get into a tussle referred to as beta-oxidation.


SCENE 2: After a bunch of chemical shuffling, CoA combines with a couple of carbon units from the fatty acid and transforms into a new molecule called Acetyl CoA.

SCENE 3: Acetyl CoA enters the Kreb’s Cycle, which is a generator that makes energy, called ATP.

The fatty acid keeps getting broken down in the same way until it’s completely gone. At every step, more energy is created.

Fat Burning vs. Sugar Burning

As far as your body is concerned, breaking down fat for energy is much harder than breaking down glucose.

To burn fat, you need to convince your body that burning fat is worth the effort.

You can do this in three ways:

  1. A daily fast
  2. Choosing the best fat burning foods
  3. Exercising

How To Get Your Body To Burn Fat More Often

Now that you know your body will only burn fat when your blood glucose level is low, you can find ways to make this situation happen more often.

One word of warning: Push your body too hard by starving yourself, completely cutting out carbs or exercising excessively and it will push back and do bad things like cause relentless cravings, burn off your muscles instead of your fat, or ruin your kidneys.

1. A Daily Fast

We all do a daily fast when we sleep, but extending that fast by a few hours, could boost your fat burning.

Fasting lowers your blood glucose level, which in turn lowers insulin. Blood insulin levels must be low for your fat cells to release fat.

In my 4 Daily Habits for Faster Weight Loss, habit number four is to stop eating three hours before bedtime.

If you stop eating 3 hours before bed; sleep for 8 hours, and eat breakfast 1 hour after getting up, that daily fast of 12 hours speeds up your fat loss.

Even better, research shows that restricting your eating time to 12 or fewer hours a day helps you lose weight even without calorie restriction or weekend dieting.

(Reboot your body for weight loss with a 12-hour fast by following my Free Video Series: 4 Daily Habits)

2. Choosing The Best Fat-Burning Foods

Think about this:

If you snack all day, you never give your body time to burn fat.

If you have cereal for breakfast, and then two hours later have a donut followed a burger and fries for lunch, a Snicker’s bar in the afternoon, pizza for dinner, and ice cream for a bedtime snack, your insulin level is always elevated. Your body is constantly burning sugar, and never burning fat.

Choose foods that do not spike your blood glucose level, and you’ll speed up your weight loss.

Ideal fat burning foods have fiber, complex carbohydrates, protein, and good fats.

Make sure your daily diet contains:

  • Salad
  • Non-Starchy Vegetables
  • Beans
  • Lean Meats & Fish
  • Raw Nuts & Seeds

It’s easy to create a meal plan that includes all of these fat-burning foods, I show examples for both a 500 calorie a day diet and a 1200 calorie a day diet.

3. Exercise

The best exercise is the one you’ll do on a consistent basis.

Exercise uses your muscles, which burn glycogen stores. With this storage gone, your body is primed to burn body fat.

If you like low-impact exercises like walking, walk long enough to use up glucose stores. Try aiming for an hour of exercise a few times a week.

Don’t have an hour to spare? Shorter exercise sessions will still help. Take the stairs a few times a day, and you’ll make it more likely that your body needs to tap into fat storage.

High-intensity exercise done in short bursts is a great way to deplete glycogen. Your body must work to restore that lost glycogen, so the fat-burning effect is extended past the exercise session.

Tabata and HIIT are high-intensity style exercises worth checking out.

And don’t forget strength training.

Every pound of muscle you carry allows you to eat an additional 50 calories a day. So, if you gain 5 pounds of muscle this year, you will be able to eat an additional 250 calories every day and never gain an ounce!

Last Word…

Now that you have the answer to the question, “How does the body burn fat?” the best thing to do is take action. You’re just 4 habits away from losing weight…find out what I mean here.

About the Author

Dr. Becky Gillaspy, DC graduated Summa Cum Laude with research honors from Palmer College of Chiropractic in 1991.

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