Blood Sugar, Stress, and Feeling Hangry

“You’re not you when you’re hungry.”

I don’t know how well it sells candy bars, but I do know that it’s true, and a candy bar would probably help.

The word “hangry” has become popular lately and illustrates this idea pretty well. For those who don’t know, it’s a combination of the words “hungry” and “angry,” used to describe the feeling of irritability that we get when we’re hungry.

These feelings are actually symptoms of hypoglycemia, or low blood sugar. While the idea of feeling “hangry” has been getting more publicity, the importance of blood sugar in health is still largely overlooked, at least for those who don’t have diabetes.

Like the blaming of cholesterol for heart disease, the high blood sugar seen in insulin resistance and diabetes has been mistakenly blamed as a cause of the disease, as opposed to an effect. This has led to misconceptions surrounding blood sugar, including the ideas that “high blood sugar makes people fat and causes diabetes,” “eating protein stabilizes blood sugar levels,” and “sugar is unhealthy because it raises blood sugar.

On the contrary, maintaining a higher blood sugar, or rather, avoiding low blood sugar, is important for reducing stress and plays a major role in our health. Like many other misunderstood topics, this becomes clear when we consider how blood sugar relates to energy.

Blood Sugar and Energy

Energy allows every one of our cells to function. And, to produce energy, all our cells require fuel.

While most of the cells in the human body can use either carbohydrates or fat for fuel, the cells in our brain are unique. Our brain is the most energy-intensive of all our organs, and therefore requires fuel that produces the most energy in the most efficient manner: sugar (1, 2).

Sugar, or glucose, is transported throughout our bodies and to our brains by our blood. Our blood sugar is therefore an indicator of the amount of fuel we have available, or the amount of immediate energy our bodies can produce.

If our blood sugar is high, then our bodies have a lot of fuel available. And if our blood sugar is low, then our bodies don’t have very much fuel available.

Because our brains require sugar, and we need our brains to work in order to function (and be alive), having adequate blood sugar is extremely important. But, keeping our blood sugar up is a relatively constant battle, as our blood sugar is always dropping.

Our brains are always active and are therefore always using blood sugar, which causes our blood sugar to drop slowly over time. And, when our brains or other parts of our bodies (such as muscles or organs) are highly active, like when we’re mentally or physically active, our blood sugar drops much faster.

If our blood sugar falls too low, our brains won’t have enough fuel and will shut off. So, when our blood sugar falls, our bodies adapt.

This is where feeling “hangry” comes in. We may begin to feel hungry, irritable, angry, weak, hot, nervous, anxious, jittery, or clammy (3). We also lack willpower and the ability to think as effectively (4, 5).

These effects are due to a lack of energy and are meant to reduce our blood sugar usage while also encouraging us to eat, which would raise our blood sugar. At the same time, low blood sugar activates our stress systems.

Blood Sugar and Stress

When our blood sugar drops too low, it doesn’t supply enough energy to our brains, resulting in stress. So, there are stress-induced mechanisms in place to raise our blood sugar.

The stress hormones glucagon, epinephrine (adrenaline), and growth hormone are released first (6). These hormones lead to glucose production by breaking down liver glycogen, the body’s stored form of sugar. They also switch the body’s primary fuel from sugar to fat in an effort to conserve sugar for our brains.

If these stress hormones can’t raise the blood sugar enough by breaking down liver glycogen (either because there isn’t enough glycogen or because energy is being used too quickly), then the stress hormone cortisol is released (6).

Cortisol breaks down protein, such as from muscles, organs, or other tissues, so that it can be converted to glucose through a process called gluconeogenesis. This is the last resort to raise blood sugar and supply energy.

Simply put, stress occurs when we don’t have enough energy, and then increases energy production via stress hormones. This may not sound like a big deal, but energy is integral to our health, and a lack of energy can be quite damaging.

This is evidenced by the fact that the stress hormones glucagon and cortisol are implicated in diabetes (7, 8) and that cortisol is strongly immunosuppressive and is implicated in obesity, heart disease, osteoporosis, depression and many other chronic diseases (9, 10, 11, 12).

The relationship between stress and health is acknowledged by the mainstream health community, but the relationship between blood sugar, stress, and health is not. And it’s an important one.

Blood sugar levels have an inverse relationship with stress, which makes sense considering blood sugar is an indirect measure of available energy (13, 14).

A higher blood sugar level allows us to handle greater amounts of stressors without causing stress. This relationship is so powerful that in rats with low blood sugar, certain toxins cause severe anaphylactic shock and death, while the same toxins cause only mild symptoms in rats protected by high blood sugar (16).

And, consuming carbohydrates that increase the blood sugar reduces stress that’s already occurring (14).

So, maintaining a higher, stable blood sugar will supply our brains (and the rest of our bodies) with the energy they need while inhibiting stress and the damage that comes with it.

Blood Sugar Confusion

Much of the confusion surrounding blood sugar comes from observations in people with insulin resistance or diabetes. In these cases, high blood sugar is common and is therefore blamed for some of the damage that goes on.

But, the problem in these conditions isn’t that the blood sugar is high, it’s that sugar isn’t able to be used to produce energy in the cells. Because sugar isn’t being used to produce energy, it builds up in the blood.

In these cases, the body is always under stress because it isn’t efficiently producing energy, which explains the elevated levels of glucagon and cortisol despite high blood sugar (7817).

(Note: When the ability to produce energy using sugar is inhibited or stress is already occurring, there’s no longer an inverse relationship between blood sugar and stress.)

(If you want to learn more about what actually causes type 2 diabetes and insulin resistance, check out this video.)

How to Maintain Stable Blood Sugar Levels

Maintaining a higher, stable blood sugar level supplies our bodies with the energy they need while inhibiting stress. This means improving fat loss and virtually all chronic diseases, while also preventing “hangriness.” Here are a few simple tips to help maintain a higher, stable blood sugar level throughout the day:

  • Our blood sugar is increased by carbohydrates, so eating carbohydrates allows us to maintain a higher blood sugar level and inhibits stress.
  • Our blood sugar decreases throughout the day, even at rest, and decreases even quicker when we’re physically or mentally active. So, eating a carbohydrate-containing snack or meal every 2-3 hours and after or during physical or mental activity will prevent blood sugar lows and stress.
  • Protein decreases blood sugar, so eating protein alone will cause our blood sugar to drop and stress to occur (18). But, this is easily preventable by making sure to eat carbohydrates anytime we eat protein.
  • Thomas
    Posted at 15:41h, 30 September Reply

    It sounds to silly that humans are build to eat every 2 hours to maintain stable blood sugar. And on a low carb diet we never get that enegy dip every few hours.. why?
    And if in diabetes 2 we have constant higher bloodsugar, why do we opt for high constant bloodsugar to be heathy as well? Sound contradictig?

    • Jay Feldman
      Posted at 16:45h, 30 September Reply

      Assuming that the liver is effectively storing glycogen and glucose is being used efficiently, eating every 2 hours wouldn’t be necessary – you could maintain adequate blood sugar levels for several hours without eating without causing stress. It’s not that humans were necessarily built to eat every couple hours, it’s that the presence of carbohydrates throughout the day acts as an effective indicator of the quality of the environment. So, changes in blood sugar act as information that helps us adapt to our environment. If blood sugar is maintained at adequate levels, it indicates a fuel-rich environment and encourages increased energy production and usage, and vice versa if blood sugar is not maintained by carbohydrate consumption.

      On a low-carb diet, blood sugar levels are maintained via stress hormones and fat is the primary fuel. So there’s no energy dip every few hours, but this encourages reduced energy production and usage. Considering that energy is the primary driver of our health, this is certainly not beneficial. I explain this further in this article.

      In type 2 diabetes blood sugar levels are elevated, but this isn’t contradicting. In type 2 diabetes, the blood sugar is elevated due to increased hepatic glucose production due to excessive stress hormones (similar to what happens on a low-carb diet). This is the result of inhibited glucose production, which I explain in this video. This is different from maintaining a higher blood sugar level when glucose oxidation is not inhibited. In this case, the higher blood sugar is simply more available fuel and increases the ability to handle stressors.

  • thomas
    Posted at 03:49h, 01 October Reply

    can you make and article about fasting and low carb. There is alot of new health guros that promoting this and says its the best way to regain health. Also the zero carb and carnivore diet. Alot of hype arount that!
    Thanks for you answer!

  • GalacticWoman
    Posted at 08:36h, 22 November Reply

    This explains why when I am working hard on solving issues I reach out for buiscuits or apples as a snack. I feel a real need to eat then. In fact since I switched from low carbs to predominantly healthy carbs like oats fruits and maple syrop for breakfast ,lots of starchy veg and meat or fish for dinner with snacking on fruits throughout the day that my energy levels gone up considerably and weight has been stable at ideal weight level for months now.No longer calorie counting forme 🙂

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