Ketosis: Eating Fat with Matt

This post was instigated by my brother…


“Biological energy-types and chemical access to do work” seems like a mouthful. But by the end of this article you will be able to answer the following questions:

  • What are the two main types of energy we eat?
  • How is each type of energy unique?

While I’m using the topic of “ketosis” as a platform to communicate fundamental biochemistry; Matthew will be providing some insight into the lifestyle of someone in ketosis.

So what is ketosis?

Ketosis is a metabolic state by which a biological system (you) is using ketones as its primary fuel.

What are ketones?

Ketones are functional groups that are by-products of broken down fatty acids.

What are fatty acids?

Fatty acids are essentially long carbon chains that we use for energy. They are commonly called fat, and they look like this:

Those straight ones are called saturated fatty acids, while the ones with kinks are called unsaturated fatty acids. We’ll come back to these in a second.

Energy Types

I would hope everyone has read the back of a food label at least once.

If you haven’t, there are nifty little puzzles that spit out candy when you win.

If we turn around my can of tuna (you know I love my fish), we’ll see fats, carbohydrates, and proteins.

And some other stuff, but none that contributes significant chemical energy (the stuff that makes your heart beat and your muscles work).


Proteins are complicated molecules that are built in strands that form ribbons with blocks called amino acids. We break down proteins to use the amino acids to build our own proteins for stuff like muscles.

They look like this:


Fat refers to a package of fatty acids. And nature packages these fatty acids often in groups of three:

When fatty acids are packaged this way, they are called Triglycerides. Triglycerides are the most energy-dense molecules that humans consume. It supplies 9 cal/g (calories per gram). This kind of molecule is also where our car-fuel comes from…oil.


Carbohydrates are much more reactive molecules. This means that carbohydrates’ energy type is fast-acting more-accessible than fats. While fats contain 9 cal/g, carbohydrates only contain 4 cal/g, meaning they have less energy per weight. Especially since 3 grams of water are stored with every gram of glycogen (stored-carbohydrates).

Carbohydrates’ building blocks are sugars. The brain loves sugar because sugar is the brains primary source of fuel. It is also the preferred source of energy for doing explosive types of work. This is why body builders are so keen on carbohydrates and protein; and also why endurance athletes like runners drink liquid sugar while they are training and competing.

Sugar looks like this:

Carbon is black, hydrogen is white, oxygen is red. Note the prevalence of oxygen. Oxygen is reactive and less stable than carbon. Notice the image of fat. Does fat contain as much oxygen as a carbohydrate?

Below is another model of the same molecule. This model is designed so you can see its structure better. Notice each carbon has four bonds while oxygen only has two. Because of this, carbon has more potential energy than oxygen; while oxygen is more reactive.

This happens to be a glucose sugar. When your body harvests the carbohydrates you consume, it converts it into this version. Glucose is what your body primarily uses to power your brain, muscles, and a lot of other systems.

This is one of the most important chemicals to understand for the sake of your long life. It is a powerful storehouse that can enable your body and brain to accomplish amazing biological feats.

This is the chemical that olympians have learned to leverage for their performance advantage. However, it is simultaneously one of the most unknowingly-abused molecules that has lead to diseases like type-2 diabetes.


A keto-diet restricts the amount of carbohydrates you have in your diet. This causes the body to go into ketosis, which is a metabolic state where your body uses ketones for most of its energy—instead of glucose (sugar [simple carbohydrates]).

I mentioned that for every 1 part of carbohydrate stored, 3 parts water are also stored.

This is why so many people get excited about keto-diets. They lose a noticeable amount of weight fast. But the weight being lost is from carbohydrates and water. The true utility of a keto-diet for fat-loss comes weeks after starting the diet. It doesn’t come from some magical feature of ketosis. It comes with diligent calorie restriction—which can be psychologically easier for some when they are in ketosis. This has to do with the type of hormones each energy type triggers, which I will not be covering in this article.

Ketones largely replace the work done by glucose in systems that prefer glucose. Systems like your muscles and brain.

Brain Performance

Dopamine association

The biggest and less talked about reason why a ketogenic diet affects the brain is simply that sugar is not being consumed. Like I said, sugar is an amazing source of physical and mental energy. But when sugar is experienced on the tongue, our brains go buzzerk—we release dopamine. We love it! We want more.

And the fact that our brains experience a dopamine-spike after we taste something sweet, makes sugar both a powerful tool if learned to harness, or a reckless addiction if abused.

To stay in ketosis, carbs have to be restricted to a degree that couldn’t include sweets on a regularly occasion. Since the keto-diet does not include dopamine-spiked eating experiences, the longer you are on a ketogenic-like diet, the less your brain may crave eating.

Brains fueled with ketones

Firstly, the Atkin’s diet was a ketogenic-type diet. In 2003, neuroscientists were re-employing a phase of the Atkin’s diet, making the modified-Atkin’s-diet relative for treating serious epilepsy.

The modified Atkins diet reduces seizure frequency by more than 50% in 43% of patients who try it and by more than 90% in 27% of patients.

– Wikipedia

I’m not going to name any other specific brain studies. But if you want to do a bit more reading on some possible advantages of a brain fueled on ketones, here is a great post with extensive references.

What I will add is an opinion;  not fact.

I believe permitting your body to go into particular states for some time has its advantages and disadvantages. Performance may be a disadvantage when experiencing new states. But it also seems biological systems are stronger when they are lightly stressed, challenging the system to adapt.

Low-glycemic advantages

This plays right in with carbohydrates and sugar. Where the effects of dopamine-spikes are one consideration of sugar consumption, the glycemic index is another.

The glycemic index (GI) is an index of the bioavailability of a carbohydrate. The higher a carb’s glycemic number, the more available that carbohydrate can be to the blood stream.

This is an important index for someone with diabetes because they are at risk of having too much sugar in the blood, and therefore, want to avoid foods with a high glycemic index number. An athlete, on the other hand, would want access to high GI foods and products for certain types of activity that require lots of energy.

Too much sugar in the blood is toxic. Our body generally maintains around a tablespoon of sugar in our blood. If we dive into a pecan pie, our system will release insulin to store the glucose in the liver and muscles. When you start a keto-diet, your body uses all the available glycogen (stored-glucose [sugar]) in your liver and muscles, and then starts producing ketones from fat.

The modern-American diet often eats sugar from refined sources. The body has evolved to take sugars from their fibrous environments (like carrots). When there is too much sugar (or carbohydrates with high GI-numbers) and frequent consumption, your pancreas becomes overworked producing insulin. This is what causes type-2 diabetes: an overworked pancreas that can not longer produce enough insulin to store glucose from the blood stream.

Examples of foods and their GI range:

FoodGlycemic number
White rice87
Wheat bread, White71
Sucrose (table sugar)65
Ice cream61
Rolled oats51
Wheat bread, Whole49
Carrots, raw16
Onions, raw10
Agave syrup15

Maltodextrin? Wha? 110?! It is basically a combination of many small-chained carbohydrates. The reason its GI is higher than glucose, is because it’s not a single type of molecule. The molecules of maltodextrin are short-chains of sugar, and are easily broken down into individual sugars. But since their chain-lengths vary, they are absorbed through multiple different pathways. Maltodextrin is a great product to use for fast chemical energy. And since most of it is not made up of simple sugars, it doesn’t taste very sweet. But it is a highly functional product for food manufactures, and is included in many “sugar-free” foods. So if you’re eyeing a sugar-free product, still be aware that it might contain ingredients that are effectively sugar without sweetness.

Immersive learning

Involving yourself in a diet while learning the relevant chemical processes is an immersive learning experience that personalizes the information. I’ve learned more about carbohydrates by first learning how and why to avoid them. They are unnecessary to consume, yet a powerful energy source and behavioral tool if eaten right.

Biochemical energy types

We’ve touched on biochemical energy types and the amount of energy each contain per weight; calories per gram (cal/g):

Fats 9 | Carbs 4 | Proteins 4 | Alcohol 7

We’ve learned that carbs offer an accessible source of energy—so-called “fast burn”—that is stored in the cells of muscles (for many movements) and the liver (for brain and blood energy).

We’ve learned that when we limit the amount of carbohydrates we eat, our bodies produce ketones from fat which become our main source of energy. Though these ketones are not as “fast burning” as carbohydrates, they are the best forms of sustainable energy. That is why the heart uses fatty-acids (fat) as its primary source of energy.

Here are some good metaphors to remember the type of energy associated with carbohydrates and fat:

  • Glucose is like burning wood.
    • Cellulose (wood fiber) is a type of carbohydrate!
    • Crackling and pops from the reactive oxygen.
  • Ketones are like burning wax candles.
    • Wax is chemically like fat!
    • It burns slowly and sustainably.

I haven’t talked a lot about proteins because they are behemoths. Not really necessary for the basic fundamentals of chemical-energy. But do know, our bodies can convert proteins (or amino acids) into sugar. And our body can do this at a rate that is fast enough to not need to eat any carbohydrates.

The reason carbohydrates are seemingly so important in food advice, is because many foods that are high in carbohydrates also include important micro-nutrients such as vitamins and minerals.

There is also dated belief that the brain cannot work without eating carbohydrates. But this idea has been clearly refuted in study.

…ketone bodies, including β-hydroxybutyrate, that are produced during consumption of the ketogenic diet may serve as an alternative source of energy in states of metabolic stress, thus contributing to the neuroprotective activity of the diet. In fact, β-hydroxybutyrate may provide a more efficient source of energy for brain per unit oxygen than glucose…

– Neuroprotective effects of the ketogenic diet

Mindful eating

I hope I’ve displayed the value of understanding basic food chemistry.

Get curious! Start reading labels. The more you read nutrition facts, the more you’ll learn about which foods and products are relevant for your body and health.

The next time you’re cutting yourself a piece of pie, you’ll involuntarily remind yourself that the amount of sugar you are about to “load” to your system, might be taxing your pancreas.

I quote “load” because it needs to be considered in the context of knowing your food’s GI. Glycemic load is the load of a food in respect to its glycemic index. You can have a food with a high glycemic index—e.g. jolly rancher, probably around 100—and eat it slow and it will not have a high glycemic load. However, if you eat something with a moderate GI—e.g. ice cream, 61—but scarf it, then the glycemic load can be high enough for your pancreas to be overworked.

So sugar is not bad, its just misunderstood and easy to abuse—given its power to be concentrated fuel and an amazing dopamine trigger. Just eat your dessert slow, and don’t eat too much. That, or take your sugar with a tomato.

Functional eating

I mentioned that knowing how glucose works can effectively turn you into a competitive athlete. I’ll write more on how to take advantage of glucose (or glycogen) for common goals. But if you’re itching for something like this now, here is a great article on cognitive performance and glucose, another on carbs and glycogen, and another on exercise performance with sugar-water.

Fatty acids can also be used for certain types of energy goals too. MCTs, or medium-chain-triglycerides, are in particular fashion right now because they are the most efficient type of triglyceride to do work. So athletes on a keto-diet often like to consume these types of fats more often than not. Coconut oil is a good example of a popular product with a decent amount of MCTs. And some manufactures sell isolated MCTs.

Amino acids selection can enhances performances too. But I’m not quite ready to share on that. I will be writing more about how to use carbohydrates, proteins and fats for better performances. If you want to stay updated with new posts, subscribe!


The ketogenic diet is in my pocket, and though not my favorite type of diet, I can think of a number of reasonable contexts where I would want to be in ketosis. It has its pros and cons. And that is partly what makes it great. A different way for our bodies to use chemical energy. And that just might suite a future situation nicely.

There is obviously a lot to be said, and my brother’s post rounds out more about what a ketogenic diet can look like. I got to introduce you to some important key-terms, and I hope they will help you along your journey of learning how to efficaciously manage chemical-energy.

If you have any questions, shoot. If you’d like me to expand on a particular point, ask. And if you have anything to add, please comment.



Ketogenic diet, Wikipedia

Glycemic Index

The fat-fueled brain: unnatural or advantageous?

Neuroprotective and disease-modifying effects of the ketogenic diet

All images are linked to their attributors. Most of them being published through Wikimedia Commons. The images used in the feature image, are the same images used in the post.

  • dsprindle

    Learned a lot from your post. I’ve have experimented with all the above. Always tend back towards a diet that is high in carbs.

    • Ben Prindle

      That’s because you’re an athlete! Carbs are my favorite too. It’s funny how the unnecessary can also be the source of optimization.