Carbohydrates, Insulin, and Health: Unpacking the Complex Relationship

May 29, 2023

Martin Kuchynka

This comprehensive exploration delves into the multifaceted effects of carbohydrate consumption on insulin, inflammation, and glycation, while also examining the historical context of dietary paradigms and the role of genetics in determining individual carbohydrate requirements.

What we’ll talk about

The more carbohydrates you eat in the long term, the more insulin your body produces. Low insulin sensitivity leads to a larger amount of undigested glucose and other nutrients in the blood. It also leads to hyperglycemia – glucotoxicity, which increases the inflammation of the entire organism. Glycation is a spontaneous, non-enzymatic reaction in our body, when a sugar molecule (glucose, galactose and others) binds to another protein or fat molecule. The rate and amount of glycation naturally depends on the level of blood glucose.

50 years ago, Ancel Keys formulated a low-fat paradigm that blamed the rise of cardiovascular disease, obesity, diabetes and cancer on excessive amounts of saturated fat in the diet. This resulted in another 50 years of carb dominance and fat demonization. The sugar era has created an unshakable paradigm about the benefits and necessity of carbohydrates. More and more passionate scientists, doctors and the public are advocating for this carbohydrate bubble to be burst. The number of obesity-related diseases is many times higher than 50 years ago.

The Effects of Excessive Carbohydrate Consumption

Let’s look at carbohydrates in more detail.  We will reveal the hidden corners of how it is possible for people to willingly consume so many carbohydrates that has a negative effect on their health, yet still fight for them, enjoy them and refuse to reduce their consumption.  We’ll also talk about why it’s not just how many carbs you eat, but where they come from and where do we come from, getting to the age-old question of genetics versus environment.

But first, let’s look at why an excessive amount of carbohydrates in the diet is harmful to the body:

Reducing insulin sensitivity

As written in previous post, the more carbohydrates you eat in the long term, the more insulin your body produces, which results in a gradual decrease in insulin sensitivity, leading to further insulin production and an increase in the proportion of nutrients that your body will store in the form of fat tissue.

However, this is not the only effect of low insulin sensitivity.  It is also associated with a larger amount of undigested glucose and other nutrients in the blood, which leads to hyperglycemia – glucotoxicity, which increases the inflammation of the entire organism.

Increasing the inflammation of the organism 

Although the emergence of inflammation is a functional defense mechanism of our body, ensuring our adaptation and survival, a general and especially long-term increase in inflammatory processes is harmful to health.

Inflammation can be present, for example, at the level of the intestines in case of food intolerances, at the level of muscles destroyed by heavy training (this is a healthy process, however, if it persists for a long time, anabolism cannot occur) or at the level of a certain organ, where they can contribute to its inadequate function.

Systemic inflammation then occurs with increased toxicity of the organism, for example due to the mentioned glucotoxicity, when inflammatory molecules are formed throughout the body. In addition, a large number of carbohydrate foods are naturally pro-inflammatory, for example cereals. Our genetic predisposition predicts, how the body will react to them, whether better or worse (see below). On the other hand, some fats are anti-inflammatory and have the ability to reduce inflammation in the body (primarily omega 3, but also short- and medium-chain saturated fats).

The exact consequences of long-term systemic inflammation are not yet fully known, however, an increase in inflammatory processes throughout the body occurs equally in all civilization diseases.

Excessive glycation

Glycation is a spontaneous, non-enzymatic reaction in our body, when a sugar molecule (glucose, galactose and others) binds to another protein or fat molecule, which subsequently change its properties.

The rate and amount of glycation naturally depends on the level of blood glucose, and although these processes are harmless under normal conditions, they increase with increased blood glucose until they can reach pathological levels.

If the increased level of blood glucose, and thus the amount of glycation, persists for a long time (in the order of months), advanced glycation products (AGE) are formed, which subsequently damage tissues and organs. Their increased presence was discovered both in Alzheimer’s dementia and in cardiovascular disorders and diabetes, where it is related to the progression of diabetic retinopathy, nephropathy and polyneuropathy (which explains the negative effect of increased insulin, and therefore glucose, mentioned in the previous text, to our health).

One of the products of glycation is the binding of a sugar molecule to blood hemoglobin, resulting in so-called glycated hemoglobin, whose blood value (HbA1c) is not only a good indicator of long-term blood glucose levels, but also the rate of aging.  Glycated hemoglobin is therefore a key indicator of insulin sensitivity, as well as health.

Historical Perspective on Carbohydrates

After reading the previous text, you might think that carbohydrates are the greatest evil in the world, and you need to cut them off immediately, bury them and never mention them again in decent society.  However, this would be looking at the world of nutrition and human health through a one-dimensional peephole.

Carbohydrates are not a priori bad, only their excessive amount is bad, i.e. excessive amount and low-quality, human-degraded sources.  These appear both in the typical American diet loaded with junk food and in seemingly healthy bodybuilding and fitness menus.

Where did they come from?

Ancel Keys' Low-Fat Paradigm

The whole story begins and ends with the industrial era, which, in pursuit of maximum profit, has on the one hand paid for incredible campaigns, thanks to which everyone in the developed world today “knows” that it is good to eat carbohydrates for energy recovery, and on the other hand, stands for the last fifty years of genetic modification of cereals, especially wheat and corn, resulting in an increase in their protein content, including prolamins, which our body tends to treat as antinutrients and resist them. In addition, these efforts were also reflected in the creation of industrially processed sugars and syrups, which can be found in most packaged meals and foods today.

At the same time, no one thought of equating the skyrocketing food industry, thriving on the mass cultivation of cereals and the production of industrially processed sugars, with the epidemic of civilizational diseases, led by obesity and diabetes.

In the beginning, something terrible happened, the consequences of which our society carries to this day.

Fifty years ago, Ancel Keys (among other things, the author of the first controlled research on starvation) formulated a low-fat paradigm that blamed the rise of cardiovascular disease, obesity, diabetes and cancer on excessive amounts of saturated fat in the diet.

This resulted in another 50 years of carb dominance and fat demonization. After 50 years of the low-fat paradigm, when plant-based margarines were preferred over butter, yolks were separated from whites, people avoided eating red meat and instead focused on consuming as much carbohydrates as possible, which formed the base of the nutritional pyramid, it became clear, that the number civilisation diseases in society is many times higher than 50 years ago!  Bravo, applause, fireworks cut through the night sky.

Challenging the Carbohydrate Paradigm

From nutritionists and trainers, to doctors, to housewives and young children, the sugar era has managed to create an unshakable paradigm about the benefits and necessity of carbohydrates that only in recent years, along with the exposure of methodological flaws and corruption of earlier research, slowly begins to release its terrible secrets into the light of the world.

More and more passionate scientists, doctors and the professional public are advocating for this big carbohydrate bubble to be burst, for fats to stop being demonized and people to finally look at industrially processed carbohydrates with sober eyes instead.

And in the same way, we will now look at carbohydrates: If possible, without the prejudices represented on the one hand by their unlimited adoration and on the other hand by their complete condemnation.

The Real Role and Requirements of Carbohydrates

Carbohydrates as a Source of Energy

There are essential amino acids that our body cannot produce and we have to get them from our diet. There are even essential omega 3 and omega 6 fatty acids (i.e. fats) that our bodies cannot produce and we have to get them from our diet.  However, there are no essential carbohydrates or sugars. Our body can produce them itself from other macronutrients (gluconeogenesis) or stored energy reserves (from glycogen and fats), or even get rid of them completely and find alternative sources of energy.

For this reason, there is no such thing as a necessity to eat carbohydrates to survive, maintain health, or just transform your body.

That being said, carbs are not all bad. As part of our metabolism, carbohydrates (glucose) are used for the rapid generation of immediate energy or to replenish muscle and liver glycogen. They are also the primary source of fuel for our brain, which fatty acids from the blood can’t get to (which is why, if you eliminate carbohydrates out of nowhere, your cognitive performance will decrease after a few days). But that’s all. Dot.

Carbohydrates are not needed for anything else, and as said, most of these sources can be produced by our body from other macronutrients and energy reserves.

So the answer to classifying carbohydrates is not in a YES/NO format, but rather more complicated.  According to the AboveYourLimits system, a number of intervening variables come into play, which indicate the amount of carbohydrates you must/can have in your diet.

Factors Influencing Carbohydrate Intake

1. Body fat percentage

Not only the level of your insulin sensitivity, but also the ratios between other hormones indicate to what extent your body will use carbohydrates for the anabolism of muscle mass and to what extent it will be stored in the form of reserve fat.  From the point of view of AYL, the degree of insulin sensitivity and the overall hormonal balance can be viewed according to the percentage of your body fat. It will therefore be the one that will indicate the total amount of carbohydrates that you can indulge in every day.

2. Origin and sources of carbohydrates

The second variable is from what source you can get your carbohydrates according to body fat percentage. The criteria will be the type of food and its glycemic and insulin index, its origin (whether from organic, conventional or genetically modified agriculture), method of processing and the associated amount of antinutrients and toxins present. It makes a difference whether you eat 60 g of carbohydrates from parboiled white rice, genetically modified wheat, garden-grown potatoes or organic millet.

The glycemic and insulin index are important, they indicates the increase in blood sugar, or insulin, as a result of the consumption of the given food. In general: While with low insulin sensitivity we will not want to increase blood glucose and insulin too much, with high insulin sensitivity our goal will be to use the anabolic effect of insulin to build muscle mass and we will therefore deliberately increase it.

3. Genetic predisposition for carbohydrates and their digestion

There are individual differences in the extent to which individuals are adapted to digest and metabolize carbohydrates, animal proteins, and fats. Most of the Central European population is made up of descendants of Neolithic gatherers and early farmers, which makes their bodies less adapted to digesting red meat and saturated fats, and instead more adapted to digesting carbohydrates, especially grains.

Unfortunately, thanks to this, they have insufficiently efficient digestion and detoxification, and paradoxically, they react more poorly to foods with a higher content of antinutrients, which include the aforementioned cereals and legumes (i.e. widely used sources of carbohydrates).

As part of the metabolism, such people are primarily set to use glucose for energy, which predisposes them to eat smaller carbohydrate meals more often during the day.

If they consume an increased amount of industrially processed carbohydrates, these people suffer more often from insulin and estrogen dysregulation, which is behind the increased deposition of resistant adipose tissue and predisposes them to the development of civilization diseases.

In addition to them, however, our society also includes a smaller percentage of people who are descendants of Paleolithic hunters, have a stronger genes, including digestion and detoxification, are more resistant to antinutrients in food and more adapted to eating red meat and saturated fat. Metabolically, such people are primarily set to fat metabolism, which allows them to eat larger portions of food less often. At the same time, they also have no problems with the consumption of carbohydrates, including those from foods rich in antinutrients.

Thanks to their genetic dominance, they are more resistant to disease and hormonal imbalance.

While your body fat percentage will dictate the absolute amount of carbohydrates you can eat and the sources from which you can get them, your genetic predisposition will dictate the relative amounts you will function best on and the specific types of foods you will find satisfactory (which you don’t have intolerance). The protocol therefore indicates the limit values within which your individuality decides on a specific quantity.

Above Your Limits


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