Carbs seem nowadays to be as devil-like as fats were back in the golden ages of bodybuilding and colorful aerobics clothing. Many diseases such as prevalent diabetes, obesity, and sugar addiction seem to relate to carbohydrates. Moreover, nowadays, we consume way too much sugar and carbohydrates within our Western Diet. Many foods have added sugar and lots of calories within them because it is an easy way to manipulate our human food centres to crave more of the food we’re eating – that’s why even things as pizza or bagels will have added sugar.
But is this a reason to damn them entirely?
I don’t think so. I rather think it is about context, the context of carbohydrates you individually use. And saying carbs cause diabetes and the plethora of other metabolic diseases is too simple. They contribute for sure in the evolutionary inconsistent amounts nowadays – but there is more to this story.
In this guide we’re digging deep into carbohydrates as a substance, how your body uses them, where our ancestors would’ve encountered carbs, to which common diseases they are related and if the best answer is us all going Keto. Let’s embark on this bumpy ride!
What are Carbohydrates?
Carbohydrates as a Substance
Carbohydrates are molecules with a particular atomic makeup ratio.1 Commonly they’re also known as sugars, carbs, or saccharides. We win energy from them by transforming it chemically into glucose which is used by all organisms to produce energy. Glycolysis is an ancient cycle to win energy out of those.
Each gram of Carbohydrates provides your body with 4kcal.
Carbohydrates are classified based on their chain length into monosaccharides, disaccharides, oligosaccharides, and polysaccharides. While the chain length is believed to be the main factor in the total speed of digestion, modern research suggests that this process is dependent on many other factors.3
Science has no answer to this anomaly yet. Only fats seem to not cause huge insulin spikes.
How does the Carbohydrate Metabolism within your Body look like?
Step I: Break-Down to Sugars
First off, this is a vast topic that employs lots of scientists, doctors, and biochemists. In fact, diabetes research is a huge industry with knowledge far beyond my tiny bit of apprehension. That’s why we’re going into this subject on an understandable, but sophisticated level.
Alright, after this disclaimer let’s start the journey at the beginning – in your mouth. Let’s say you eat one Oreo or 20. Hopefully, you chew them and they get in contact with your saliva. It already contains a molecule that breaks down sugars – Amylase.4 Amylase’s main job is to cut carbohydrates to size – ultimately into Maltose. Besides a better feeling for satiety, this might be the reason why your mum always called you out on eating way too fast.
Alright after chewing your Oreos you swallow them. In your esophagus nothing interesting happens it is solely a pipe, but as soon as they enter your stomach the fun begins. Here come even more enzymes into play – like sucrase, lactase, and guess it more amylase.5
This enzymatic cocktail breaks down all digestible carbohydrates into glucose, lactose, fructose, galactose, and maltose. All these sugars are mono – or disaccharides which your small intestine can begin absorbing right after. Remember:
- All carbohydrates are cut down to size, sugar size
- Amylase is a fairly new genetic adaptation to farming and more nutritional starches, roughly after the split from Neanderthals
- The small intestine takes up glucose into the blood-stream
Mission successful – energy is in your blood. Blood glucose levels rise.
Step II: Use Glucose
Too much or too little Glucose can get very dangerous quickly. You best see this in diabetic patients who have to be adjusted to their optimal dose and be strictly adhering to it. They lack your body’s control mechanisms – aka insulin – and therefore have to help your body through an external supply of insulin:
- A crash in glucose can range from light shakiness to unconsciousness or even death
- A big pike in glucose over a longer period could lead to high ketone levels and damage nerves and vessels.
But remember all these conditions are exaggerated and a few extreme exemplary symptoms. There are many stages and a healthy person has the best observer – their incredible body.
That’s why your body strictly manages your blood glucose levels – mostly through insulin and glucagon. These two guys are peak competitors and metabolic masterminds:
- The former get glucose, protein, and fats out of your blood into your cells and inhibits new build-up in the liver. It’s mainly an anti-catabolic hormone. Moreover, it has 1.000 additional effects as your primary metabolic hormone, but going into this would explode this post. It is a beast of a hormone.
- The latter does the opposite and is a beast, too. It is your main catabolic hormone. Therefore, it raises blood glucose levels by promoting breakdown of the stored glucose. It also affects fats.
Despite those storing functions, both fulfill many other functions and insulin receptors are widely spread throughout your body.
Now that blood glucose levels are back to baseline and the glucose is stored in the cells they get either burned or stored. Generally your body stores glycogen within your muscles – roughly 300-500g. On-demand these stores undergo glycolysis to create Pyruvate, an intermediate metabolite, that gets transformed to acetyl-CoA. Acetyl-CoA on the other hand enters the Krebs-Cycle. The goal of all these transformations is the creation of energy-rich cofactors – mainly NADH and FADH. After all those steps, energy is finally won by recycling ADP to ATP within the electron transport chain – the cofactors are used to create a gradient of H+-Ions outside the mitochondrial membrane. Pretty complex stuff that mitochondria do, right?
Your head’s still where it is supposed to be? Great dude! We are through. With the secretion of glucagon or insulin, your body can control the levels tightly.
Carbs in the Light of Human Evolution
Where do Carbohydrates occur in nature?
Take a look outside and think about your surroundings wherever you live. Carbohydrates are scarce, right? Most likely they’re available seasonally when fruits ripen in summer or tubers can be dug out in autumn. This was the default condition before agriculture was invented.
Moreover, the fruit we nowadays see at grocery stores is not comparable to ancient fruit, tubers, and plants. Over centuries, some were refined for human consumption:
- Fruits became sweeter and bigger
- Many plants grow more harvest per plant
- Plants lost antinutrients and their bitterness
All of this occurred to the thanks of genius farmers – before they even heard of Mendel and his rules. They intuitively took two plants of a trait they wanted to enforce – such as bigger harvest or sweeter fruits – and crossed them.
The same goes for domesticated animals. A chicken nowadays is much meatier, to the extreme that their internal organs can’t work properly because of their rapid growth.
But back to carbohydrates – in nature, they occur seasonally. There are no berries in winter. Plus, you could only eat fruit, honey, and some tubers. That’s it. Nobody would eat leaves, as our intestines aren’t made for the fermentation process – unlike many of our primate cousins.
Our Guts are unique
We, humans, are omnivorous – our guts represent that. I’d go so far and term the human as a facultative carnivore, with the ability to fall back onto plants in times of scarcity and famine. Our guts resemble those of wolves more than guts of other primates:
- They’re shorter in total and specific lengths
- They rely more on putrefying digestion than fermentative processes
- Our stomach acid is much more aggressive on the level with scavengers
That’s an indication to me that we strive on eating animals, but also can survive on plants. So after this gut 101, how do carbs come into play?
Carbs found in nature are often sugars in the disguise of fruits, honey, or starches in other non-toxic plants. Our gut generally handles those well. Problems can arise when we try to feed our gut what fermentative animals eat – lots of leaves, a lot of fiber, and starch. You feel bloated.
All those require fermentation through the gut microbiome to be transformed into short-chained fatty acids which we absorb. And this takes time. That’s one reason why herbivore guts are much longer than ours – to process complex carbohydrates and fiber better. Plus, they need to deal with all the antinutrients in plants and the issue that plants try to hold on to their nutrients through an array of protective chemicals.6
Humans adapted to Starches & Agriculture
With the rise of agriculture, our diet strongly changed. Of course, this didn’t happen overnight and was a process, probably out of pure necessity. Agriculture started to rise, as humans overhunted the megafauna to the point that hunting probably couldn’t sustain the population. Nonetheless, anthropologists found out that our diet changed. 7
One astonishing adaptation is the production of amylase, an enzyme there to break down complex starches. And humans are unique in this ability – Neanderthals don’t possess this gene at all. It seems this was an adaptation to agriculture and the cultivation of more starchy vegetables. Amazing what evolution all manages to invent, right?
The Big Question – Are Carbs Healthy?
Like any ‘… are healthy?’-question the answer is it depends. In case of carbs even more so. Sugars can be healthy, carbs can be healthy, but both can also wreak havoc onto your system and reduce your lifespan by years. It depends on:
- Your general activity and energy needs
- The total amount of carbs you eat in relationship to other macros
- Timing of carbs and sugar
- The general makeup of your meals
- Chain-length of the carbs you consume
- Other diseases which could interfere
- Are you eating PUFAs, smoking, drinking?
- …and many more
But I don’t want to leave you solely with a crappy ‘it depends‘-answer for the matter of playing it safe. Just understand that it is a damn complex topic and addressing something general can be tough, as so many factors play into it. Another big one is Polyunsaturated Fatty Acids aka PUFAs for example.
Carbs aren’t necessary
Unlike fat and protein, carbs aren’t essential. You can survive without the other both for short periods of time, but cutting them out will quickly lead to issues. Carbs are different. Your body can run entirely on protein and fat for a long time.
That tells me that carbs are a beneficial source of energy and easy to use for your body – while they’re available. But likely they weren’t very available all the time.
Nonetheless, I think that being in ketosis all the time is neither optimal. Adding in carbs from time to time, especially in sync with the seasons is a good thing to do as an active person. There are reports that perma-ketosis can wreck your testosterone for example. And much about topics like the influence of carbs on the gut microbiome, the production of short-chain fatty acids, how fiber from animals plays into this, is still unclear and needs more research.8
What about Sugars? Are they to doom?
Sugars are what all carbohydrates that enter your mouth will eventually be transformed into. So what is the difference?
Let’s look at uptake speeds and blood glucose first. Most often it is the quickness with which the carbohydrates can be absorbed within our gut. Complex carbs need more time to be broken down, than sugars in fruit that only need to be extracted, or even processed sugars that are readily available at instant:
- The quicker your body can absorb carbohydrates the sharper the spike of blood glucose will be.
- That said complex carbohydrates, and bound carbohydrates like sugars in apples for example, tend to end in less of a spike than refined sugar right off the spoon.
Thing is, often the spike isn’t the problem – what is more important is how quickly your body can bring it back to baseline that tells you a lot. And how often you run around with elevated blood glucose levels, for how long. That’s where devices like CGMs can be handy.
To answer the question as with anything – it depends strongly on the sugars you consume, the amount you eat in total and per meal, what you eat with it, plus how your body responds to it. In general sugar from the right sources up to around 100g-150g of carbs a day, if you’re metabolically healthy shouldn’t be a problem. But that’s just my personal view from an animal-based diet. Others strive on high-carb diets. Nonetheless, you should prefer natural sources like fruit or honey, that are seasonally available. And stay away from all forms of processed carbs, refined sugars, and too many starchy or fibrous carbs.
The Special-Case: Fructose
The good ol’ fructose-myth. Why do I say myth? Glad that you ask – let me tell you!
Fructose differs from glucose in that solely your liver can transform it to glucose, while nearly every cell within your body can use glucose. That said looking at epidemiology, fructose can be tied to non-alcoholic fatty liver disease, elevated triglycerides, and LDL-cholesterol. All markers of metabolic health, or in this case metabolic disease.
So where can we find fructose naturally? In honey and fruit. Oh, oh. That must be a reason to stay away from honey and fruit! Unfortunately, that’s how the public seems to reason when flawed epidemiologic data comes around the corner.
What people forget to mention is that fructose is found in huge amounts in soft drinks, sweets, candy, cereals, bottled sauces, and all that nutritional garbage. Wouldn’t it rather make sense that humans develop these elevated markers and conditions, because they eat like assholes or have other pre-existent conditions that might influence all of that? Or is it fruit and honey that’s to blame?
Right here you find an example of the flaw of epidemiologic data – if the group you look at is sick by default like over 80% of Americans with metabolic health deviations – it can be extremely misleading. Maybe the default diet might be to blame rather than two ancestrally consistent foods. Damn, fruit might be the reason we evolved trichromatic colour vision. The fruit in the garden of paradise granted us the ability to see good and evil if we want to speak in mythology. 9
That said, don’t fear fructose – fear nutritional garbage and flawed data sets. Eat fruit and honey, in amounts that you could find in nature, and you’ll do fine without your liver looking like you’ve been binge-drinking for decades.
How to handle Carbs & Sugars in your Nutrition
Limit your overall Carbohydrate Consumption
First you should look at how many carbs you consume a day. Most likely you will consume a high carbohydrate diet, as this is the default western diet nowadays. Cereal here, bread there, and a bit of rice. Unless you actively chose a low-carb diet or keto approach looking at the overall carbs you consume and measuring it for a couple of weeks is a great starting point to get a rough picture.
After this time you should know how many carbs you consume, what kind of carbs, plus the other stuff that you normally eat. Tracking is a great tool to learn nutrition and make it measurable!
There is no perfect answer to how many carbs you should eat per day, humans are very different in that matter. I for example enjoy a lower-carb diet, intermittent fasting, whole day fasts but nonetheless consume around ~150g of carbs per day. Other’s flourish with even fewer carbs, while others seem to strive for higher amounts of carbohydrates.
My advice would be to experiment – go keto for a month, try low-carb for some time, and look closely at how you feel. But make sure to choose your main source of fuel – either fats or carbs, not both. 10Most will do best with their diet containing all three macronutrients and shouldn’t go keto. Nonetheless, the experiment can lead to deeper insights!(/efn_note] The most important part is to cut out garbage and processed foods.
Eat Carbs seasonally consistent
I love eating seasonal and think it is a great tool to add variety naturally into your nutrition. It takes some though upfront though:
- Have a look at your surrounding, depending on where you live different fruits are in season at different times
- Lookup a seasonality calendar and make a list of what fruit, tuber, fish, seafood is in season for each season. E.g. berries in summer, pacific salmon in autumn, and apples in spring.
With that list, you should know when which foods are available, and by buying it seasonally from a local farmers market you can even save money and avoid transport costs, environmental burdens, and buying food that has been stored for ages. Plus, you’ll connect to local producers and see who is responsible for your fruit.
What is even more important is that seasonal eating naturally influences the carbohydrate content of your diet. While in summer and autumn you’ll likely have more fruit, berries, and the like available in winter you’ll eat largely a keto animal-based diet, supplemented with a few storable tubers. That’ll make for a higher amount of carbs and sugars in the summer, and a lot less in the winter. Although an animal-based diet mainly focuses on the least toxic plants all of those still contain certain antinutrients, and by eating seasonally you naturally cycle through these antinutrients by changing your plants.
To learn more about ancestrally consistent practices you can grab the perfect guide to an animal-based diet below, for free. It summarized the mega-long post I wrote on that topic and distills the main points into this actionable guide.
Don’t be afraid of Fruits, Honey & other non-toxic Plants
As already said, fruits, honey, and tubers are what we evolved with. There is no reason to fear those unless you react to some specifically. While modern public media seems to damn those because of their sugar and fructose content, the ‘foods’ you should avoid are processed foods.
Coming from a carnivore background, all of those contain antinutrients, but I truly believe that those likely won’t harm you, especially if you add variety and seasonality, and don’t eat 2lb of apples, topped with tablespoons of honey a day. Despite what public opinion often suggests, there is a lot more nuance to things and our world is not black and white – rather a 1000 shades of grey.
Supplement your diet with ancestrally consistent amounts of carbohydrates, ditch the garbage and keep it simple.
Time Carbs and Sugar strategically
Bodybuilders inject insulin as it is one of the strongest anabolic hormones. You can also manipulate insulin to a certain degree without going roids.
- By consuming sugars and fast-digestible proteins* around your workout and spiking up your insulin intake on intent you can use its anti-catabolic effects for your good.
- Keep insulin at bay, by fasting or building in some high-fat days to reap those benefits.
That said, consuming carbs around your workouts is a great timeframe to consume those. Eat a carbohydrate-rich meal a few hours before you exercise and if you like eat quick carbs like sweet fruit or honey pre-workout or intra-workout. That’ll give you energy, as well as consciously spike your insulin and blood glucose levels.
Keto isn’t the Answer – Metabolic Flexibility is!
Most of us never experience running out of carbs. And when they do they refer to it as hitting a wall from a performance point of view. But fortunately, you can train your body quickly to adjust to ketones as a fuel source – in fact, humans are awesome at starving and living off stored fat.
Most will reach this point after your carbohydrate reserve of ~300-500g of carbs is empty. This will be after around 1.500-2.000 kcal or roughly 16 hours.
There are many ways to practice and get used to this important pathway:
- Fast for ~16 hours, one whole day, or even more
- Go keto for some time
- Have 1-2 days per week only eating mostly fats
- Have 1 -2 High-Carb followed by 1-2 Low-Carb weeks
Being-keto adapted has many benefits because modern nutrition runs entirely on carbs. But running on carbs also has benefits if you run on fats for a longer time. It is about metabolic flexibility, rather than adhering dogmatic to one or the other camp.
We all have to find what works for us, our bodies, and our lives individually. While for some the answer is ‘keto’, for most it is not. Most will get by much better eating every macronutrient. Most will do best not following extremes and sticking to the basics. Sticking to the above guidelines when it comes to carbs.
Nutrition is very individual, that what’s makes it challenging. We all don’t even know ourselves well and what we want, what we like. Figuring this out in a highly marketed domain, with lots of bro-wisdom around and soaring numbers of diseases is a challenge. That for sure. But I am sure you’ll get there!
Knowing carbs and sugar, which kind of carbs are good for you, and how this fits into the whole framework of nutrition is a big chunk. Nonetheless, I want you to keep it simple. If you only take a few points back home these are the points that will have the biggest impact:
- Keep it simple
- Eat in sync with the seasons
- Ditch the nutritional garbage
- Lower your carbohydrate consumption to 50-150g per day
See you in the next post and stay sweet,
Footnotes
- They all contain a carbon, hydrogen, oxygen ratio of 1:2:1
It is important to know about carbs because their intake directly increases blood glucose levels and relates strongly to insulin secretion. As a fun fact aside, other macronutrients also cause insulin secretion such as proteins – quite a big one.2https://pubmed.ncbi.nlm.nih.gov/16002802/
- Depending on your genetic luck some people produce a higher amount of amylase and others fewer. The gene is known as AMY1
- In fact more amylase enters your incorporated portion of Oreos right after it leaves the stomach directly from your pancreas – for more information read this post about amylase https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6825871/#:~:text=In%20the%20human%20body%2C%20amylase,of%20various%20origins%20%5B10%5D
- https://www.doctorkiltz.com/are-humans-carnivores/
- https://www.academia.edu/45399287/The_evolution_of_the_human_trophic_level_during_the_Pleistocene
- https://www.frontiersin.org/articles/10.3389/fendo.2020.00025/full
- https://www.sciencemag.org/news/2017/02/you-can-thank-your-fruit-hunting-ancestors-your-color-vision
