Metabolism In Eating Disorder Recovery

We’ve all heard the term “metabolism” but what does it really mean?

Some common answers to this question include:

“It helps you burn fat.”

“It increases when you workout, have more muscle, and when you eat protein.”

“A slow one makes you gain weight or struggle to lose weight.”

“A fast one keeps you from gaining weight and you can eat a lot.”

While all of these are accurate statements, they do not really tell us what the metabolism actually is!

Your metabolism basically means the energy your body requires to function. We acquire energy in the form of calories from food.

Just how many calories do our bodies need to function well? The number is different for every person. You may notice on the nutritional labels of the foods you buy that the “percent daily values” are based on a 2,000 calorie diet — 2,000 calories is a rough average of what a person needs to eat in a day, but your body might need more or less than 2,000 calories. Height, weight, gender, age, and activity level all affect your caloric needs.

There are three main factors involved in calculating how many calories your body needs per day:

       1. Basal metabolic rate

       2. Physical activity

       3. Thermic effect of food aka Thermogenesis 

Let’s break those down:

Basal Metabolic Rate (BMR)

Your basal metabolic rate (BMR) is the amount of energy your body needs to function at rest. When I say at rest, I mean laying in a bed, sleeping for 24 hours, not moving a muscle (this DOES NOT mean lounging around watching TV). This accounts for about 60 to 70 percent of calories burned in a day and includes the energy required to keep the heart beating, the lungs breathing, the kidneys functioning, body temperature stabilized, digestion, hormone balance, hair and nail growth, menstruation-every single internal process requires energy!  

A person’s actual BMR changes over time. There are many factors that influence BMR but those relevant to the topic at hand include:


-Stress—Physical stress, such as recovering from an illness, increases your BMR; mental or emotional stress can increase or decrease your BMR. Stress may cause anxiety which can increase BMR or it may lead to lethargy or depression and decrease your BMR.

-Fasting—This is surprising to most people as fasting actually lowers your BMR.

-Eating disorder recovery- Depending on the individual, can either decrease or increase BMR

In order for your body to sustain normal organ function, you need to eat enough calories to at least meet your basal metabolic rate. Anything below this will result in a decreased metabolism and potential to go into starvation mode.  


Thermic effect of food (TEF)

Body heat is produced in response to the food eaten by a person. This occurs when the food is digested, absorbed, transported through the intestinal tract, metabolized, and stored. About 10% of the calories consumed by a person are used for TEF. For example, if you eat 2500 calories a day, 250 of them are generally used in TEF.

Physical activity

This amounts to about 20-30 percent of the body’s total energy output. Energy expended during physical activity varies with the level and duration of the activity. Physical activity includes everything from making your bed or sitting in a chair to marathon running.


Now that we have a background in how our body uses calories to function, lets move on to the real topic of this article!

Today, we will be talking about metabolism in eating disorder recovery. Navigating meal plans and using skills during recovery is challenging in itself! Worrying about how your metabolism may change during the recovery process is totally normal! And take it from me, it does change, but it changes for the better! Listed below are two totally normal paths that your metabolism may take in the initial recovery process! 

 1. An Overactive Metabolism:

What’s so bad about a fast metabolism? Isn’t that what everyone wants? Requiring more energy (food) is not a bad thing; but it can be a chore to eat enough and is super difficult if you are trying to restore weight.

Unlike those who can easily skip breakfast or “forget” to eat lunch, those with an overactive metabolism are so sensitive that if they were to do these things, it could cause a set back (unwanted weight loss, relapse, etc.).

For these folks, eating is not an option; it is a necessity—and they need to be extra mindful to keep pace with their increased metabolism.

Initially during treatment and recovery, a crazy fast metabolism is often referred to as “hypermetabolism” (fast metabolism) and it is actually considered a relatively normal part of the recovery process. Think back to what you just learned about your Basal Metabolic Rate- first, you need enough calories to sustain normal organ function. Then, you need more calories to fuel the digestion of the food you just ate. And then, you’ll need more calories as fuel for any kind of physical activity throughout the day. When you’re very malnourished, your body needs even more calories on top of all that to begin to heal itself. Finally, after all of these things are taken care of, THEN your body can start using any remaining calories for weight gain! It takes 3500 calories ABOVE what your body burns to gain 1 pound. Because of this, some individuals may require upwards of 3500-4000 calories of fuel per day in order for healthy weight gain to occur.

Often times this hypermetabolic state occurs because the body is FINALLY being given the fuel its been longing for all along.

Think about a 14-year-old boy hitting his growth spurt. His mom jokes that he must have a hollow leg because he is literally eating everything in sight—anything he can get his hands on…and yet…the food seemingly goes nowhere. This is how the body often first responds in recovery—as there is A LOT of damage and repair and lost time to be made up for (mending bone, hair, nails, electrolyte balance, hormones, tissues, etc.).

Once a healthier weight range and regular nutrition is re-established (your body is not fearful it will go without), the hypermetabolic mode begins to fade (typically 6-12 months after maintaining a healthier state).

2. A Sluggish Metabolism

On the flip side, because severe dieting and stress lowers your metabolism, if you’ve suffered from an eating disorder, you may find you struggle with the opposite: a sluggish metabolism.

This can make the process difficult when it seems like, once you start eating “normally” and taking care of yourself, your metabolism is not kicking into high gear. This is also normal in recovery. The metabolism can decrease by up to 50% when you are consistently eating below your BMR. Your body gets stressed since it doesn’t have enough calories to sustain itself, so it slows the metabolism in an effort to conserve as much energy as possible for later use since it’s unsure when it will be fed again! How do you change that? Focus on eating enough and focus on consistency! Our body loves routine. If you eat a similar amount at around the same time everyday (ideally every 2-3 hours), your body will learn that it can use all of that energy immediately since it trusts that it will be fed again in another few hours- there’s no longer a need to conserve energy for later! This also takes time and effort. It can take anywhere from 6-18 months for the metabolism to increase to it’s pre-eating disorder speed.

No matter which metabolic state most resonates with you, here are some ways to support it in recovery:

Remind Yourself. Recovery is a process, both internally and externally. Your body is continuing to heal. It’s busy re-establishing bones, muscles, cells, brain cells—all parts of you. The damage done to your body did not happen overnight, and while you may not be able to see it, your body is coming out of a traumatic event. In order to support this part of recovery, more fuel is often necessary. 

Try to Relax. If you come from a background of chronic dieting or over-exercise, you come from a background of STRESS. And this constant state of stress taxed your adrenal glands (the “stress regulators”). In order to keep up with the demands you placed on your body, you were more than likely running off cortisol which is increased when the body undergoes both physical or emotional stress. Yes, exercise is good for us, however over-exercise is considered physical stress! Studies show if a 200 pound woman is limited to 800 calories a day, after just three weeks her metabolism may decline by 15 percent — possibly prompting further, unrealistic calorie reductions which cannot be sustained. Remarkably, exercise actually exacerbates the problem. If a person isn’t consuming enough calories and is exercising, the body — which automatically does the math and reacts to an even more severe calorie deficit — will reduce its metabolism further.

 Another study found that: Metabolic rate progressively decreases with dieting, an average of 0.9% per day with a total decrease of 12-17% after only 2 weeks. Now that you are no longer restricting your calorie intake or hitting the pavement, your metabolism can finally re-awaken and your adrenals can FINALLY relax! Malnutrition, stress, and lack of sleep are the most common reasons of adrenal fatigue!

Try Not to Under eat. Even though you are in recovery—and perhaps no longer binging, purging or actively restricting, some individuals may slip back into under eating (particularly if you don’t have much of an appetite and eating continues to feel like a chore). Chronic under eating basically means living off less than what your body ultimately would like to thrive. Contrary to popular belief, in order to have a high metabolism, you actually need to eat more calories, more often. And if you already have a higher metabolism…this is why (you finally started feeding your body!).

Ditch the Deficiencies: Just because you are in recovery, does not mean you are “in the clear.” Vitamin and mineral deficiencies are still very possible! How do you know if you’re deficient? It’s not a one-size-fits-all answer, but as an insurance policy, it’s best to at least take a daily multivitamin. I recommend this multivitamin

Give Grace: If you’ve been through an eating disorder, and lived to tell about it, the experience you went through is not considered a “normal” experience for human bodies to undergo. Instead of trying to problem solve or pinpoint exactly why your metabolism is not yet back to normal—do your best to meet your body where it’s at today. Honor your body by taking the best possible care of yourself—physically and mentally. You beat yourself up for far too long. Do the opposite today and choose life in recovery! Your body (and health) will follow suit.

rillie12 Written by Kayla Rillie, RD 



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