The Science Behind Extreme Hunger in ED Recovery

Defining Extreme Hunger

So first thing’s first: what exactly is extreme hunger? While there’s obviously no dictionary definition of extreme hunger, there are definitions of the words “hunger” and “extreme.” According to Merriam-Webster Dictionary:

• Hunger: a craving or urgent need for food or a specific nutrient

• Extreme: reaching a high or the highest degree, i.e. very great.

Put together, extreme hunger can be defined as a very urgent need for food or specific nutrients.

What I love about this definition is that this definition doesn't limit extreme hunger to physical hunger. A huge misconception is that extreme hunger is only "valid" if it’s physical, but there are several ways in which extreme hunger can present itself, including (extreme) mental hunger, eating-induced hunger, and exercise hunger.  Before getting into these different types of extreme hunger, we must first understand why extreme hunger occurs.

What Causes Extreme Hunger After An Eating Disorder?

Extreme hunger is your body’s way of getting you back to a healthy state as quickly and efficiently as possible. When we are malnourished, our body goes into energy deficit, which means that the amount of energy or the amount of calories we are taking in is insufficient to support the amount of energy we are putting out, or “burning.”

Worth noting is that you don’t just burn calories when you’re exercising – just being alive requires energy! Think about keeping your heart beating, digesting food, or even the signals that your brain is constantly exchanging with all of the different parts of your body!

When you've restricted for a prolonged period of time, we tend to have forgotten how much fuel the body truly requires – even at rest. The reality is that your body is never truly resting. Your cells are constantly multiplying, which means your body is constantly at work! Unfortunately, when us humans can’t see something, we often jump to the conclusion that nothing is happening, and then we overcomplicate things by trying to control natural biological processes...

You may go on a diet, exercise to burn additional calories, or engage in other compensatory behaviors that ultimately result in a negative energy balance. But where does extreme hunger enter the picture? For the body, energy deficit is perceived as a famine. Specifically, your brain stem perceives a famine. The brain stem is the oldest part of your evolved brain and has the sole role of ensuring your survival. The brain stem is the first part of the brain to develop, and because some animals, such as reptiles, have only a brain stem, it is often referred to as the primal brain or the reptilian brain.

Your Reptilian Brain on Food

The reptilian brain is responsible for anything that has to do with survival – including food! Its sole purpose is to make sure you stay alive and keep the human race intact. And what’s one of the biggest threats to human survival? LACK OF FOOD! So, when you do go on a diet, overexercise, or do anything that causes you to consume less calories than your body needs, your brain stem perceives your environment to be scarce.

In reality, sometimes resources are scarce. (Not so much anymore with Starbucks and McDonalds being everywhere nowadays, but thousands of years ago there were times when food was so scarce that people were forced to adjust.)

When we experience short-term stress – such as undereating or overexercising – our bodies are pretty resilient. When the body trusts that this scarcity is only temporary, there’s no real long-term issue. The issue is when energy deficit continues for a prolonged period of time, such as a restrictive eating disorder like anorexia, bulimia, ARFID, or other forms of caloric restriction. In this case, we can speak of energy debt. Energy debt is a lot like financial debt, in the sense that you must eventually pay it back.

The Impact of Energy Deficit on Your Body

Before we get to the paying it back part, you must understand what happens to the body when you are in energy deficit and building up energy debt. As you just learned, undereating is perceived as a famine, AKA your body believes there is not enough food around. In other words, your body does not trust that resources are abundant. So, if the body cannot rely on there being food, it will adjust in an effort to lessen the requirement of said food.

Said another way: if you are expending less energy, you obviously don’t need to consume as much. This is generally what people mean when they use the terms “fast metabolism” or “slow metabolism,” as some people naturally burn more or less calories than others. But, no matter what your Basal Metabolic Rate (BMR, the rate at which you burn energy at rest) is, your metabolism will slow down if you are undereating. Your body will start to conserve energy in order to keep you alive. If your body continued to give out as much energy as before, you’d run out pretty quick, which would result in death. And isn't that exactly what your primal brain is designed to prevent?

During periods of restriction, your body starts to economize, resulting in the slowing (or even stopping) of bodily processes. Your heartrate slows, you are constantly tired, you feel cold as your body cannot produce as much heat, your metabolism slows, your digestion slows, your hair and nails get brittle, you get the idea. But this is just the beginning…because as you continue to undereat, your body also must continue to economize.

When your body has no clue when food will be readily available again, it continues slowing down processes, and even stops certain processes that are non-essential to life. An example is a missing period in people who menstruate – because why the heck would your body waste energy on a period if it could use that precious energy to keep your heart beating? Not to mention its lack of trust of you feeding a baby if you can barely feed yourself!

For a while, your body may be able to sustain this caloric economization. However, as you continue your day-to-day life and use precious energy on other activities (and perhaps, even engage in excessive movement), your body starts to build up energy debt.

If you're not providing your body with energy, it’s going to seek other places to acquire that energy, including your bones and organs. In other words, your body starts eating itself up. Your bone density decreases (which can lead to osteoporosis) and your brain shrinks, which can result in irrational thinking and other mental health issues. Yes, this is all very scary, but it’s simply how the body works. We need fuel to function, and your body will do anything it can to access that fuel.

The Start of Extreme Hunger in ED Recovery

Perhaps now, you realize what danger your body is in, so you finally start fueling it properly. You start eating more, you stop exercising, and you start the process by which your brain stem can trust that it’s no longer in a famine environment. But then...BOOM!

After eating more and giving yourself plenty of rest for a couple of weeks or months, you suddenly experience insatiable (mental) hunger and feel like you’re a bottomless pit. Or perhaps you just cannot stop thinking about food, even when you are stuffed and nauseous. This my friend, is the start of extreme hunger. 

You may be wondering: Why now? Why didn’t I have extreme hunger when I was eating less? Why do I have extreme hunger if I'm already weight restored? With the understanding of how your reptilian brain perceives food shortage and will direct the body to conserve energy to optimize chances of survival, it is completely logical that you get extreme hunger at a later stage of eating disorder recovery. In fact, most people experience extreme hunger when they're no longer underweight according to BMI. As I write in my book How to Beat Extreme Hunger, I personally didn't have extreme hunger until I was at the highest weight I'd ever been in my life!

Because I had been deemed "weight restored" and was even advised to stop gaining weight by "professionals," I believed my body was broken. I believed I had damaged my body beyond repair, I was developing a food addiction after anorexia, and that my extreme hunger was a sign that I was now "swinging to the other side" and developing binge eating disorder...but that's not quite how the cookie crumbles.

When you start eating more and gaining weight, your body learns that it’s not actually in famine environment, yay! It now trusts that hunger cues will be honored, so it finally starts sending them out. And back to our beautiful definition of “extreme": it will start sending them hunger cues out in a very great degree.

No matter what weight you are at and no matter what any "professional" may have told you, extreme hunger is valid. Now, it's time to understand the four different ways in which extreme hunger can be recognized. 

Four Different Types of Extreme Hunger in Eating Disorder Recovery

Physical Extreme Hunger is what most people in recovery describe as the "bottomless pit hunger" or the inability to feel physically full after eating a significant amount of food. The scientific term for this insatiable physical hunger is post-starvation hyperphagia, which can be defined as an increase in the sensation of hunger and overeating after a period of chronic energy deprivation that can be part of an autoregulatory phenomenon attempting to restore body weight. In other words: feeling incredibly hungry after a period of restriction is a completely normal and healthy biological response to get your body back into energy balance.

Mental Extreme Hunger falls into this same category, as it's just another way in which your body is trying to get you healthy again. I get SO many questions around whether mental hunger "counts," including:

• Has thinking about food just become a "bad habit"?
• Have I neurally rewired my brain to be addicted to food?
• Am I just using the term "mental hunger" as an excuse to emotionally eat?

Of course, the underlying question regarding extreme mental hunger in ED recovery is: Should I honor mental hunger even if I feel physically full (and perhaps even nauseous) after satisfying my physical hunger?

I’m going to start off right by saying that YES, mental hunger ABSOLUTELY counts. If anything, it's more important than physical hunger in those moments that you do already "feel full" or don’t feel physical hunger at all. The reason I say more important is because mental hunger can be the very reason that allows us to eat and nourish ourselves if we are lacking physical hunger cues. To understand this, let's revisit the idea of energy conservation...

When your body believes your environment is scarce, bodily processes will slow or cease to conserve energy. Every single action in your body costs energy, from cellular division to breathing. Considering the fact that the body does not want to "waste" precious energy when resources are scarce, it will put any non-essential signals on the back burner – including the act of a rumbling stomach or any other physical signals that our brains receive when we’re physically hungry.

When your body possesses sufficient energy, i.e. you're NOT in energy deficit, the body is willing and able to sacrifice the energy of sending out a hunger cue in good trust that it will get its return on investment (that return on investment being eating). However, when you ARE in energy deficit (and this can still be the case if you're not "underweight"!), your body is not yet willing to sacrifice energy on a physical hunger cue because it still doesn’t have complete trust that this hunger cue will be met with food.

This is where mental hunger is your savior. The body is smart and knows that you need more energy, so it will think of alternative ways to signal you to go out and seek out calories. And what's the most cost-effective way to signal hunger? Thinking about food! Because simply having a thought costs way less energy than having a physical cue. This concept is the very reason why most people with anorexia (or are malnourished in any other way) constantly think about food and experience mental hunger; it’s your body’s way of telling you that you’re hungry, while it’s being smart and conserving energy!

How Do I Recognize Mental Hunger in Anorexia Recovery?

Now that we understand why mental hunger is important, the next step is learning to recognize it – because honoring mental hunger in eating disorder recovery is a critical aspect of becoming fully recoverED.

Mental hunger can be recognized by obsessively thinking, planning, or dreaming about food or anything that has to do with food. Perhaps, this is planning your next meal, worrying about what food is going to be available at the dinner party, or thinking about how you’re going to restrict in order to deserve food later in the day…that’s ALL mental hunger!

You may be thinking: "Well that can’t be possible because I’m ALWAYS thinking about or planning food! Livia, if that’s your definition of mental hunger, that would mean I’m ALWAYS hungry?" And yes, exactly!!! You’re right: you probably ARE always hungry. But because you’ve conditioned your brain to constantly ignore or distract yourself from these food fantasies, you’ve tried to micromanage and control the very simple message that your body is telling you. Mental hunger is closely tied to constantly feeling like you need to be productive, because constantly doing something is a mechanism in which you’ve tried to distract yourself from thoughts about food. If you want to learn more about mental hunger and its sneaky manifestations, be sure to pick up a copy of my book How to Beat Extreme Hunger!

Other Forms of Extreme Mental Hunger in Eating Disorder Recovery

Along with physical hunger and mental hunger, there are two additional types of hunger that must be addressed in the context of extreme hunger in ED recovery.

Exercise Hunger is a form of mental hunger that isn’t as obvious as "thinking about food" because you’re not directly thinking about food…so it can almost be considered as a disguised form of mental hunger! If you are thinking about exercise as a means to "deserve" food or have permission to eat a certain number of calories, you are experiencing mental hunger. Trying to work out ways (no pun intended!) in which you will allow yourself to eat more food is always mental hunger.

Once again, it's worth stressing that "exercise" goes beyond working out at the gym, running, or any other traditional forms of movement. Any type of compensation – whether this be pacing, needing to take the stairs, not allowing yourself to sit down, purging, etc – are all ways in which you are trying to "deserve" food, meaning they’re all ways in which you’re trying to disguise your mental hunger.

Eating-induced Hunger is hunger that has been triggered by eating. Have you ever started eating something without being particularly hungry, only to find yourself absolutely starving halfway through, or even after the meal? Eating-induced hunger is that confusing hunger that makes you believe your body is broken or that your fullness signals are messed up. But...just like extreme hunger in general, eating-induced hunger makes complete sense from a biological perspective.

As previously established, your body will not send out physical hunger cues if it believes there is a food shortage. When you start to eat (more) food, however, your body receives the notion that it is not actually in a famine environment and thus, it understands physical hunger cues to be appropriate. I know eating-induced hunger can feel SO irrational and can be connected to the fear that you'll never stop eating, but just like mental hunger, it's your body's way of telling you it needs food!

However it presents itself, extreme hunger is your body’s way of telling you that it needs more food. Trust me, I know it can be absolutely terrifying and difficult to honor a bodily signal that you’ve conditioned yourself to ignore, but honoring extreme hunger in ED recovery is the only way to end your obsession with food once and for all.

Extreme hunger does end, the mental hunger will lessen, your weight will settle within your unique healthy weight range, and your body will trust you again. But first, you must prove to your body that it can be trusted. You must prove to your body that food is abundant and you do this by eating in abundance. If you'd like more guidance on your extreme hunger journey in ED recovery, be sure to grab a copy of my book How to Beat Extreme Hunger and enroll in my course Extremely Hungry to Completely Satisfied!