How Does The Keto Diet Break Down Fat?

How Does The Keto Diet Break Down Fat?, Keto Diet, Ketosis -

How Does The Keto Diet Break Down Fat?

People were told to fear dietary fat, that eating more than a few eggs per week would be like putting one foot in the grave.

Thankfully, in the 21st century, we’re educated enough about nutrition to understand that eating food with cholesterol will not raise our cholesterol.

The ’90s were a decade of scare tactics and warmongering… the war against dietary fat, that is.

We no longer tremble at the sight of butter or cream. In fact, the needle has shifted to the opposite end of the spectrum with the increased popularity of high-fat diets.

A keto diet can be really simple, but it helps to learn some basic skills.
These tips and guides will help you answer all the common keto questions.
Click here for An Easy Detailed Guide to Follow for Beginners to The Keto Diet.

Butter and fats

Ketosis: The bolts and nuts

Ketosis is the metabolic state in which the body switches its primary fuel source from carbs to fat and ketones. We need the energy to function and survive, and our bodies usually get most of that energy from glucose.

Following a diet whereby you devour fats all day (including bacon, cheese, and other high-fat indulgences that previously you might have stored alongside the rat poison) may feel unnatural for fat loss - like voluntarily jumping off a rocky cliff blindfolded.

We eat carbs and protein, the carbs and excess protein break down into glucose, and the glucose contributes to the creation of ATP, which fuels us.

So what happens when we stop eating carbs, and our glycogen stores have been sucked bone dry? Thankfully our bodies have the mind-blowing ability to completely switch metabolic pathways. When carbs are minimised, and I mean really minimised, ketones are used as an alternative source of fuel.

We break down fats into fatty acids, which then are burned off in the liver to create ketones. These ketones can then fuel our brain and muscles. To simplify it, when there’s a carb drought, ketosis steps in and we use both stored fats and consumed fats as energy to survive.

How Does The Keto Diet Breaks Down Fat?

The main idea behind the ketogenic diet for fat loss is to use body fat as fuel. The goal is to eat so low carb that we force our bodies to break down our own fat in order to function.

On the ketogenic diet, with carbs low, our bodies need to use glycerol from fatty acids in order to produce glucose (but under normal circumstances it doesn't use the fatty acids themselves).  


Producing glucose from glycerol is fairly inefficient, meaning our bodies have to break down a lot of fat to get a little glucose. Anytime our bodies do something inefficient it uses more calories than doing it the efficient way.

Macros keto


The ketogenic diet is different from other low carb diets in that your glucose levels have to be so low that you have to moderate even the amount of protein that you consume. With 40% of calories coming from protein, protein will convert to glucose once consumed, which is not keto friendly.

In order to reach ketosis, you need to meet these macronutrient ranges:

  • Fat: 70-75%
  • Protein: 20-25%
  • Carbs: <5% (this will most likely turn out to be 30-50g per day)

keto food

Types of food

Typically you won’t see bread, pasta, rice or oats on any keto menu.

The only fruit you’ll be eating on this diet is avocado, and even nuts need to be monitored as they can sneak in an unexpectedly high number of carbs. Like with all diets, processed foods are not recommended.

Protein: Grass-fed and hormone-free varieties are the go-to here. Other than that, if it once was alive and now isn’t, you’re good to go, within limits.

Vegetables: This isn’t a diet that allows you to eat veggies to your heart’s content. Most of your vegetables should come from leafy greens like lettuce, spinach, and bok choy. You can also fit in some asparagus, cauliflower, and broccoli. As a rule of thumb if it’s a colour other than green, avoid it.  

Fats: When it comes to types of fat to consume, anything goes. It’s recommended that you consume a mixture of saturated and monounsaturated fats. Things like coconut oil, which contains medium-chain triglycerides (MCTs) help keep ketone levels high. So long as you’re keeping your carbs in check, if you want to go as far as swigging bacon grease to get your fat in, you won’t be the first.

The proof

There is substantial scientific evidence that when keeping calories constant, the ketogenic diet can lead to greater fat loss than higher-carb diets.

Scientists have recognised the positive effects of ketones for fat loss for a very long time.

One study that was conducted on obese people back in 1971 by Charlotte Young, Ph.D., from the American Society for Clinical Nutrition found that the ketogenic diet leads to a greater fat loss for obese individuals, but what works for obese individuals might not hold true for the rest of the population.

The participants consumed 100g, 60g or 30g of carbs per day. Weight loss and fat loss were inversely related to the number of carbs consumed across the board.

Young established that the ketogenic diet leads to a greater fat loss for obese individuals, but what works for obese individuals might not hold true for the rest of the population.

Bodybuilders are generally concerned that cutting their carbs will affect their gains.

But according to the International Society of Sports Nutrition, it won’t. Two groups of resistance-trained and semi-fit men were put on the same training schedule. Half of them followed a 'Western diet' (55% carbs, 25% fat, 20% protein), and the other half followed a keto diet (5% carbs, 75% fat, 20% protein).

Both groups consumed the same number of calories. After 11 weeks, not only did participants in the keto group lose more body fat, they also gained more lean muscle mass.

bodybuilder keto

The downsides of a ketogenic diet

Formulating the diet properly: The ketogenic diet allows for a lot of flexibility when it comes to the types of fats you consume. However, if most of your calories are coming from beef and bacon, fibre is left in the lurch. And when the fibre is left in the lurch, your gut suffers. Don’t care about gut health? You should. An unhealthy gut is a major obstacle to fat loss. Supplement with probiotics to ensure your gut stays in good shape.

The transition period: In the first few weeks of the diet, you may feel like absolute crap. Scratch that, you most likely will. Your body won’t be used to using fat as its primary fuel source, leaving you with decreased performance and a lingering foggy-headed feeling. However, as your body adapts, your energy will increase. You might even find yourself feeling better than ever.

Metabolic flexibility: The ketogenic diet is not metabolically flexible. On the diet, your body adapts to using fats for fuel, which, in turn, means it is no longer adapted to using carbs efficiently.

People have the tendency to follow the diet strictly for a few months, get the results they want, and then switch right back to a carb-happy diet.  If you introduce a lot of carbs when your body isn’t adjusted to handling them, you may gain back all of the fat you lost, if not more. It's often the case that many people gain fat after reintroducing carbs because their calories inadvertently go up or they get nutrient timing wrong.

When transitioning out of keto, re-introduce carbs carefully to ensure your suffering wasn’t all for nought.

The conclusion

Unlike other fad diets, like the lemon and cayenne pepper diet which further engrained yo-yo dieting and binging habits in First World women across the globe (because literally starving yourself is clearly a revolutionary and highly effective fat loss method), the ketogenic diet is based on science.

If you haven’t tried keto on for size, maybe give it a go. Just remember to do the proper phase-in and phase-out.