Insulin Resistance

Insulin resistance is a health problem occurring in an increasing number of people in the modern world. This metabolic deficiency is often discovered only after it has taken hold and when the first serious symptoms appear, meaning that the health and normal functioning of the individual have already been compromised.

This text basically originated after a pleasant and successful collaboration with the medical informative portal eKlinika, for which I wrote on the same topic, but I have since significantly expanded it and dedicated more time to it. In this text, I explain what insulin resistance is, what its causes are, and how changes in diet and habits can influence its prevention.

What is insulin resistance?

Simply put, insulin resistance is a slow and poor response of the body to sugar intake. In a healthy organism, after sugar intake, insulin is secreted. Insulin, like a key, opens the door for sugar to enter the cells, so in this way, the concentration of sugar in the blood decreases, which further leads to a reduction in insulin concentration. However, if cells stop responding to normal amounts of insulin in the blood, sugars remain in the bloodstream, which leads to the secretion of additional amounts of insulin.

Insulin resistance leads to two main problems. The first is that high concentrations of sugar remain in the blood for a long time. This is a problem because sugars are energy-rich molecules, which makes them highly reactive (they interact with many things). When they stay in the bloodstream for a long time, sugars "collide" with other blood components such as proteins, fats, and cells, damaging them and rendering them nonfunctional, and sometimes even toxic. The second problem is high concentrations of insulin, which, besides regulating sugar, has a number of other functions in the body. A chronically elevated level of this hormone can affect various tissues and cause an entire cascade of negative effects on health and quality of life.

Patients with insulin resistance often notice appetite disturbances, including a lack of feeling full after finishing a meal or feeling hungry very soon after a meal. As a consequence of this, changes in physical appearance and impaired health occur, which are the most common reasons patients reach out to me.

Risk factors

We still do not have a definitive answer [1][2][3] on exactly how insulin resistance develops, but we know that some people are at higher risk of developing this disorder.

There are numerous factors that increase the probability of developing insulin resistance, some of which are: genetic predisposition, stress, meal regularity, obesity, food choices, regularity of training and movement, sleep quality, habits like alcohol and smoking, age, the balance of vitamins and minerals, etc. I would say that, generally speaking, insulin resistance is connected to the overall quality of life and self-care, rather than to a single key factor.

The role of diet in controlling insulin resistance

Insulin resistance is a very common problem today, and most people I work with have it to a greater or lesser extent. For this reason, it is very thankless to talk about the dietary habits of such a large and diverse group of people. However, insulin resistance is strongly linked to poor dietary habits, so when we talk about the prevention of insulin resistance, we are actually talking about general recommendations for a higher quality diet.

Poor food choices, especially an excessive intake of foods high in added simple sugars like sweets and juices, as well as an insufficient intake of nutritionally rich foods like grains and vegetables, have drastic consequences on increasing the risk of insulin resistance. Additionally, meal regularity and having structured meal times help the body prepare for food and digestion. This further aids the body's insulin response and the maintenance of blood sugar levels. Contrary to this, skipping meals, sudden periods of fasting, a constant absence of hunger, and an unstructured meal schedule lead to sharp changes in blood sugar and, consequently, insulin levels, resulting in increased insulin resistance.

Therefore, with regular and established meals, choosing good foods, and avoiding foods rich in simple sugars, the consequences of insulin resistance can be drastically mitigated. If there are no sharp spikes in blood sugar concentration, there won't be a sharp and excessive release of insulin either, so cells will have time to increase their sensitivity and return to a normal state.

Given that insulin resistance is a reversible disorder, a proper diet not only helps in controlling symptoms and effects but can also help in body recovery and increasing insulin sensitivity. It is worth mentioning that while this process is possible, it is not fast and can last from a few months to several years. According to various studies, the duration and effectiveness of dietary changes lead to significant improvements in this condition, but depending on the degree of resistance, obesity, and the chosen diet, 8 to 12 weeks are needed for the first significant results.

While, as mentioned, we do not have a clear mechanism for the onset of insulin resistance, we have been aware for at least five decades of the strong link between type 2 diabetes, i.e., the prediabetic state, and excess weight. People with excess weight have, according to various sources, between a 3 and 4 times higher chance of developing diabetes. Also, it is known that reducing body weight can decrease the risk of developing this condition, so we can also view the role of diet in controlling insulin resistance as a way to reduce weight.

The reduction of fat reserves can take place in two ways: by increasing energy expenditure or decreasing energy intake, and ideally through a combination of the two. On both paths, there is a series of obstacles for people with insulin resistance, which can be misunderstood and seem unjustified to people with a healthy metabolism. On one hand, training can be made difficult by body weight, leptin resistance, and other conditions such as heart troubles, anxiety, hypoglycemia, etc. On the other hand, improving diet is hindered by changes in appetite, blood sugar drops, and the body's hormonal response to weight change. When a sharp reduction in reserves occurs, the body tries to compensate for the loss by reducing expenditure, so despite a reduced food intake, results can be very slow and discouraging.

As there is no single and effective way to reduce weight, there is no single recommendation that can be given either. Different approaches have different effectiveness in different people, which is why an individual's diet must be approached on a personalized level.

What to eat, and what to avoid?

The general rule is that one should focus on nutritionally rich whole foods and avoid foods with a high content of simple sugars, as well as those with a high glycemic index. The glycemic index is a measure of the speed at which blood sugar increases after consuming a certain food item. When food has a high glycemic index, it means it causes a sharp spike in blood sugar, which is particularly dangerous if there is no adequate insulin response from the body.

While it is easy to say avoid this and that food, in real life, this is much harder. On one hand, we are biologically programmed to like what is forbidden, and on the other, amidst daily events, it is not possible to stay focused on diet always and everywhere. That is why my approach is based on the absence of strict, hard prohibitions, for example: you must never eat that. Instead, I advise my clients to try to thin out the intake and reduce the quantities of certain foods, or even better, to focus on adding and trying new foods, which will spontaneously make the unhealthier choices less frequent.

There are several groups of foods that should be avoided or minimized. These foods mostly come as packaged products from stores, i.e., as ultra-processed food. The biggest problem for sugar control is sweetened beverages of all kinds because the sugars are already dissolved and easily available, giving them an ultimately high glycemic index. Additionally, they do not give us any feeling of fullness, so we can consume them in huge quantities. Sweetened beverages include carbonated sodas, energy drinks, flavored "waters", iced teas, regular teas with sugar/honey, natural juices, and all other liquids with a sweet taste.

Other products to avoid for similar reasons are white bread, rice, pasta, sweets, cookies, cakes, ice cream, and other desserts. All these foods are digested relatively quickly, contain a lot of sugar, their sugars are of poor quality, and they lead to a sharp spike in blood sugar, which adversely affects insulin resistance.

Additionally, if we look at 100 grams of chocolate, it matters whether the whole chocolate is eaten at once or over the course of several hours, as well as whether it is eaten on an empty stomach or after a meal. So, besides the food items themselves, there is a whole series of changes in habits that can contribute to a more stable blood sugar level and increased insulin sensitivity.

On the other hand, complex carbohydrates are digested gradually, meaning that sugars pass into the blood slowly and evenly. In this way, blood sugar and insulin levels remain stable. Additionally, the intake of quality proteins, healthy fats, and dietary fibers can positively affect insulin resistance by creating a better feeling of fullness and stabilizing blood sugar.

Foods to favor include whole grains and pseudo-grains, vegetables, especially green leafy vegetables, fruits, especially berries, nuts, and lean sources of protein, such as chicken, fish, beans, and lentils.

I am of the opinion that there is no perfect number of meals in a day, but rather that the number of meals should be adapted to the person and their obligations. Any number between 3 and 7 established meals throughout the day can be appropriate. In people with insulin resistance, there are benefits to a higher number of meals to further stabilize sugar levels, but this can cause great stress around preparation and carrying meals, thus doing more harm than good.

Fasting and periodic starvation (intermittent fasting) have proven positive effects on insulin sensitivity and on many other processes in the body. You can read more about this in two extensive texts, the first on the topic of Intermittent Fasting and the second on the topic of Fasting in General.

Through centuries of evolution, humans have adapted well to occasional periods of fasting, and the body uses them for cleaning and repairing the organism. However, today we live in a time of abundance, and it is literally unimaginable for people to spend a day, let alone several days, without food. Therefore, while this approach has a scientifically proven positive effect on insulin resistance, in practice it is rarely useful because it is hard to persuade people to try it or apply it occasionally.

Sugar cravings and what to do

You can read much more on this topic in the text: Sugars in Diet. Cravings for sweets and simple carbohydrates are normal and expected. Simple sugars are biologically and socially connected with a feeling of pleasure, reward, and success. For this reason, there is no simple solution for sugar cravings, but there are plenty of things that can be done preventively to ease periods of craving.

My stance is that one should not look for substitutes for favorite sweets, but rather focus on reducing the frequency and quantities of sweets and improving other habits. With a good meal schedule and planning, reaching for sweets out of hunger can be avoided. When planning, a good time for sweets is after the largest meal because in this way, sweets serve pleasure rather than satisfying hunger, while at the same time, the absorption of sugar in the stomach is slowed down due to its contents.

Additionally, storing sweets in the house should be avoided. In that way, another barrier is placed between the desire and its satisfaction. I often tell my clients that if they don't mind walking to the store to buy a sweet, it's not a problem to do so because they truly want to eat it. On the other hand, if they already have sweets in the house, they will frequently reach for them even when they don't really want to eat them, but are instead hungry, nervous, or bored.

The importance of physical activity and sleep

Good habits, including training, sleep, and mental well-being, significantly contribute to practically every aspect of health. There is a handful of excellent scientific papers indicating the great importance of good habits on insulin resistance.

Physical activity and insulin resistance

Physical activity is, alongside dietary changes, the most significant contributor to recovery from insulin resistance. As this is not my area of interest and study, I can only present the results available in papers.

Expectedly, the benefits of increasing physical activity are influenced by the intensity, type, and length of training. A very good research study showed that 3 to 5 workouts per week over a period of 12 weeks leads to a significant increase in insulin resistance improvement, and reduction of insulin and blood sugar levels. The authors of the paper conclude that introducing physical activity (cardio training, strength training, and combined training) leads not only to an improvement in insulin sensitivity but also in functionality and quality of life.

Another study, published in the most recognized scientific journal Nature, showed that cardio training over eight weeks reduces blood insulin levels, and additionally improves cardiovascular health and strength in young women. Similarly, a study that examined the effects of combined training over a period of 12 weeks showed a significant improvement in insulin sensitivity in the most vulnerable population, postmenopausal obese women. Finally, a meta-study (a paper that reviews many other papers) showed that cycling, strength training, and combined training have significant positive effects on blood glucose levels. From these three studies, it can be concluded that independent of the type of training, hormonal status, and age of the individual, an increase in physical activity helps in treating insulin resistance.

Sleep and insulin resistance

Chronic sleep problems have a significant impact on reducing insulin sensitivity, which is why optimizing the duration and quality of sleep can be of great importance in preventing type 2 diabetes and insulin resistance. Unfortunately, it seems that sleep is only mentioned in passing and that there is not enough advice for increasing sleep duration in groups that are at an increased risk of insulin resistance.

A fantastic meta-study examined the link between different aspects of sleep and type 2 diabetes. As the study included a large number of other researches, some claims are based on the examination of close to 1.5 million participants. These are, in short, the findings they arrived at:

Both excessively long sleep (longer than 8 hours) and overly short sleep (less than 7 hours) adversely affect insulin resistance, with lack of sleep being slightly worse

Based on the subjective feeling of sleep quality, people who sleep better have a significantly lower risk of diabetes. This is particularly pronounced in those over 50 years old

There is a noticeable increase in risk for individuals who are night owls compared to those who are early birds. This difference is more emphasized in obese individuals (BMI greater than 30)

Afternoon napping is negatively associated with insulin sensitivity. Anything over 30 minutes of sleep during the day leads to an increase in insulin resistance, and the longer the daytime sleep, the more significant the increase

Conclusion

Currently, there is a real epidemic of insulin resistance, and we are still not sure what the exact cause of this problem is, nor do we have concrete steps to slow down this trend. Insulin resistance is a condition that develops quietly and over years, which has strong effects on the health of the entire organism. For now, we are sure that the tendency to develop insulin resistance is strongly linked to dietary habits and lifestyle, including sleep and physical activity.

The good news is that this condition is reversible, meaning that with lifestyle changes it can be mitigated or completely cured. However, this process can require a lot of time and work. The truth is that magic solutions do not exist, but it is possible to make a smart strategy and improve habits that will enhance not only this condition but overall health as well. Additional positive news is that insulin resistance is becoming an increasingly present topic, and compared to the period five or ten years ago, the public knows much more about the causes, consequences, and treatment of this problem. Finally, the development of new generations of drugs to increase insulin sensitivity is in full swing, and I hope that in the coming years we will have even better ways to treat and control this condition.

Until the next text, greetings!