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Our Story: The Biology of Anorexia

By Rachel

Eating disorders can be induced. This realization was the missing link between everything I was learning about eating disorders and everything I was witnessing firsthand with my son, who developed anorexia at the age of 14.

How can eating disorders be induced? Simply by creating an energy imbalance in which someone takes in fewer calories than his/her body actually needs for an extended period of time.

After spending hundreds of hours trying to make sense of what was going on with my son, it clicked. My son had developed anorexia as the physical result of being calorie deficient.

I believe that this biological understanding of anorexia deserves more attention. That is why I want to share our story with you.

Jake has always loved to bike. At the end of the day when everyone else had had enough, we would see Jake still riding around on his bike. 

He has always had incredible endurance. When he was younger, we noticed that he never seemed to get tired on the soccer field. While other bikers and skiers would collapse after a race, Jake always seemed to stand strong and unmoved. Interestingly, throughout his childhood, he rarely spoke about being tired. My husband and I made note of this and often encouraged Jake to use this gift. 

In the spring of 2021, when Jake was 14, he decided that he really wanted to start training for the mountain biking team. We had always ridden bikes together as a family, but suddenly he was becoming too fast to ride with the rest of us. He was also gaining some independence during this time. There are a number of trails right out the back door of our mountain home, and Jake would go off and ride them on his own. As his parents, we found this to be an exciting new stage in life, and we were impressed by his discipline and maturity. 

Also during this time Jake received a Garmin watch, which he immediately connected to Strava. With the Garmin watch he was able to monitor his health stats and physical activity. With Strava he was able to track his personal progress on bike rides and compare his riding times to others. It was like a perpetual race. Connecting with others on Strava can be fun in itself, but to top it off, Jake found that his times were right up there with some of the top bikers in the area. Training became even more exciting, arguably addicting. 

Jake had a very successful mountain biking season that summer and fall. He won four of the five statewide races and earned second in the fifth race. He was also a leader in a number of local races, as well as in the Strava world.  

During this time, Jake should have been eating enormous amounts of food. Not only was he going through his adolescent years, in which anyone should be eating more, but he was also expending an incredible amount of energy while training.

Unfortunately, he was not eating as much as he should have been. For our family, lazy summer mornings meant sleeping in and either skipping breakfast because it was getting close to lunch time, or eating smaller lunches because of the tight timing. Our dinners were often eaten late in the evenings because the summer days are so long and everyone would be busy playing outdoors. On practice days in particular, when practice ran until 7:30, we wouldn’t eat until close to 8:30. Meanwhile, I had not increased the size of the dinners that I was making to accommodate for the needs of my three growing children, including one teen boy. As a family, we would eat the table clean, and that was that. Snacks were always available in the pantry and fridge, but in hindsight we didn’t promote them as much as we should have. Sometimes we would even limit them, thinking we were encouraging our kids to get the bulk of their sustenance through their main meals. We stressed the importance of hydration, but generally only drank water. 

When I look back and consider the amount of energy that Jake was expending during that time compared to the amount of energy that he was actually consuming, it is apparent that he must have been semi-starving. 

One day in early October, just before the final race of the season, I noticed that Jake made half a sandwich for lunch. This struck me as unusual, and my husband and I required him to eat a full sandwich. He tried to do this a few more times. I thought it might just be nerves about the upcoming race and didn’t think too much of it until later that week, at the final race of the season, when I glimpsed Jake with his shirt off. I was struck at how thin he was. A few weeks earlier, I had filled out paperwork for Jake’s upcoming Nordic season; now concerned, I looked back and noticed that his current weight was actually lower than it had been a year earlier. Putting the pieces together, I knew we had a problem. 

In mid-October I called the local health clinic, explained my concerns, and requested a physical exam. Disregarding all of my concerns, the PA confidently concluded that Jake was a normal, healthy and physically fit teen. 

I began to question myself. I didn’t know where to go or what to do. Two months passed by. Meanwhile, Jake became increasingly sicker. His weight continued to drop, his behaviors became more and more compulsive, and his mood grew worse. I will spare you the details of this horrible illness and simply say that Jake was not the child that we knew. 

Desperate, I reached out to a coach and began to find help. In January we saw a family nurse practitioner who took eating disorders seriously, and we began meeting with a registered dietitian and certified eating disorder specialist. We spent months looking for a therapist, but for various reasons, turned them down. 

Trying to get an anorexic person to eat is no easy task. It was a challenging and frightening time. But with the patient counsel of our dietitian, trusting obedience from Jake, and powerful prayers of family and friends, he did it. He ate and ate and ate. 

After five months of nutritional counseling, Jake has gained a substantial amount of weight. As his weight returned and his body healed, so did his mind. His compulsive behaviors slowly disappeared, and his pleasant mood reemerged.

I should note that Jake and I have been working through a Cognitive-Behavioral Therapy workbook together at home. To date we have completed six short sessions. However, it probably qualifies as more of a class than true therapy.

As of June of 2022 Jake is still gaining weight. His body and brain continue to heal.

Every eating disorder story seems to be different. I cannot speak on behalf of every case, but I cannot deny what I witnessed with my son. Specifically, I witnessed the biological role in the development and healing of his anorexia.

My husband and I are convinced that our son ultimately developed anorexia as the biological result of accidental semi-starvation. In other words, the amount of energy he was taking in was considerably lower than the amount of energy he was using. In fact, his body fat got so low that changes took place in his body and brain, resulting in the physical illness called anorexia. Not everyone’s body seems to respond this way, but my family happens to be prone to this illness.


Nothing that I am saying is new. The National Eating Disorder Association (NEDA) acknowledges this biological process and the “negative energy balance that occurs when someone burns off more calories than he takes in.” However, it only appears as a quick consideration in a long list of causes for eating disorders. Furthermore, NEDA emphasizes that “many people report that their disorder began with deliberate efforts to diet or restrict the amount and/or type of food they were eating,” and only very briefly notes that “other causes can include growth spurts, illness, and intense athletic training.”

As a result of anorexia, our son began to experience a number of behavioral and psychological problems, including loss of appetite, compulsive thoughts, and irritability. However, these problems were the symptoms (not the causes) of his anorexia. Nor was his illness caused by trauma; his illness was his trauma.

NEDA affirms that common symptoms of eating disorders include “extreme concern with body size and shape,” “frequent comments about feeling fat,” “preoccupation with weight and food,” “strong need for control,” “inflexible thinking,” “excessive, rigid exercise regime,” “extreme mood swings,” “sleep problems,” and “withdrawal from usual friends and activities.” Interestingly, it lists a symptom as “denies feeling hungry,” but does not recognize a legitimate loss of appetite. 

Does this mean that psychological issues played no part in the development of his eating disorder? Not necessarily. In addition to inadvertently eating too little during adolescence and a time of intense athletic training, it is likely that there were also some cognitive, emotional, and environmental factors that caused him to further over-exercise and possibly under-eat.

My husband and I believe that this is the correct picture of how our son developed anorexia. It has also served as a map for our son’s recovery. 

The brain cannot function properly without proper nutrition and sufficient body fat. I learned this reality in the thick of our son’s illness, largely in part from F.E.A.S.T. resources, but also from our own experience. It is extremely difficult to reason with someone who is suffering from anorexia and its symptoms. Therefore, our first priority was to restore his weight.

With the help of a dietitian and the mantra that “food is medicine,” our son steadily gained weight. As his weight was restored, so was his mind! His compulsive thoughts and behaviors faded away, and he was increasingly able to think clearly again. Together we can now discuss the food intake and exercise mistakes that we made, as well as the problematic social and emotional factors that may have contributed to the energy imbalance in the first place.

Note: Traditional treatment for eating disorders includes a physician, nutritionist, and therapist. For various reasons, we declined a therapist. Had we had a therapist, we may not have been able to see so clearly the healing that came from nutrition alone. While we do not dismiss the role that a therapist can have in recovery, we do want to stress the importance of nutrition for both the body and the brain. 

Why isn’t the biology behind eating disorders addressed more often? I wonder how many other people have carelessly developed this illness due to poor nutrition and/or biological factors such as adolescence, athletic training, illness, injury, or medication. I wonder how many other people have developed the psychological problems that are commonly associated with anorexia after developing the illness, despite the common stigma that eating disorders are necessarily caused by mental health problems. I wonder how many people waste critical time waiting for the mind to heal before allowing the body to eat food, which can re-nourish both the body and mind.

Although this picture of the development of our son’s anorexia may not apply to every person who has suffered from the illness, I have read many testimonies in which it does apply. And as long as some people are developing anorexia this way, it should be acknowledged more often. My hope is that this information could 1) help people, particularly adolescents and athletes, prevent from accidentally developing the illness, 2) educate people about the serious symptoms of anorexia in order to dissuade them from deliberately restricting food, and 3) encourage people about the importance of food in their recovery.


  1. Joy

    Thank you for sharing your story. In so many ways, my daughter’s trajectory with the disease matches yours. Energy imbalance led to anorexia led to severe symptoms. In our case, she was struggling with some mental health issues (mostly anxiety and OCD) prior to the anorexia diagnosis. But after an energy imbalance due to joining a highly competitive sports team, the anorexia took over and we could no longer address any of the other mental health issues until she began eating again. It is a complicated illness, and made more difficult to treat when there are co-occurring mental health issues. But what I so appreciate here is the clarity that anorexia – with our without other mental health factors – is not CAUSED by a diet, or CAUSED by parents encouraging “healthy” meals, or CAUSED by a desire to be thin. Those environmental and cultural things make ED harder to treat, but the behaviors and fears around food and weight are not the cause. They are the symptom. Thank you.

  2. Lisa

    Beautifully put. I wish I could explain this as well as you do. Our story is very similar, our son started workout after and overseas move and two week quarantine, and things quickly spiraled downwards.

  3. Michelle

    Thank you for articulating this so clearly. Our Daughter had a similar experience – running not biking and pushed into anorexia by the addition of mandatory school training on top of an already substantial training load.

  4. Rod McClymont

    Weight loss, intentional or unintentional, in a person with an at-risk neurobiological predisposition, is the most common precipitant of AN. There are a number of well characterised biological mechanisms where by fairly small amounts of weight loss can alter the balance in neurobiological function and tip a vulnerable individual into a spiral of restriction and weight loss that we recognise as AN.

    Unfortunately, far too often this is not taught to clinicians training to treat AN nor to parents and carers of the individuals unfortunate enough to get caught in that spiral.

  5. Rebecca

    Great article! It reminded me of the book “Sports Nutrition Guidebook” by Nancy Clark (registered dietician) which was recommended during a talk by a FEAST speaker (I forget which one…). It contains excellent info about ED and athletes. She is easy to read, practical, and a straight shooter about ED and how athletes are at risk. She offers excellent suggestions for high-calorie meals and snacks. I found this book very helpful even though my teen with ED isn’t an athlete.

  6. Susie

    Thank you for sharing your story. I saw a similar pattern, but anxiety also contributed to my child’s diagnosis of anorexia. We did get her a therapist, but, she needs long term therapy and refuses. An adolescent doesn’t fully understand the benefit of a good therapist. I hope as she gets older, she will seek out more help and learn to work through the harmful patterns of thought that she continues to wrestle with. Until then, we will be understanding and love and support her. She is nourished, but I don’t think she’ll truly be happy until she has learned to work through her emotions/feelings. It’s a process.

  7. annie

    thank you so much for this thoughtful and informative piece
    I believe strongly in this theory
    I have read and felt that there was a gene associated with ED much like gene for OCD which can be triggered…
    if you have this gene and you never experience quick and large weight loss you may never trigger the gene…
    but if there are 5 pple who lose same amount of weight quickly in short period of time, 4 may bounce back quickly but the one with the gene may develop ED…
    for our D it was consecutive illnesses that caused significant weight loss in 2 month period after which AN appeared…

  8. Therese Waterhous

    We saw something so similar in our daughter. As Rod says above, weight loss in a person with the genetic predisposition toward restricting becoming “comforting” sets the stage for anorexia. In our case our child was doing club soccer then experienced a fracture. Fractures are metabolically demanding and that is when I noticed the weight loss, followed by more and more odd behaviors around food. I do see that in kids who develop anorexia there is a backdrop of anxiety that also is part of the stage being set for the disorder. And you are right. We do need to teach and talk about this biological reality more. Very good post!

  9. Patty

    Excellent article and almost exactly our experience! More doctors and providers need to understand this phenomenon, as well as parents so they can immediately recognize a problem or better yet, hopefully prevent the trigger. Thank you for your eloquent and educational post.

  10. Christy Boese

    Thank you for sharing this. I believe something similar happened with my daughter. She is a cross country runner and used to be a competitive synchronized figure skater. She was growing and athletic and successful at both sports, but took them so seriously she trained for both one season and dropped weight and eventually felt she had to restrict. We stopped the figure skating, but allowed her to keep running. She improved and restored weight over a 6 month period. Her brain recovered from an increase in calories and fat intake. We thought all was well again, but when we gradually let her be more in control of her food intake, she dipped down in weight by 5 pounds over the summer and didn’t pass her sports physical at age 16 this fall. She missed her cross country season, but now is eating well and is up 10 pounds and maintaining while starting cross country ski team practices. We are not going to stop watching closely this time. She has weight checks every 2 weeks. And therapy weekly. Thanks for sharing your story.

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