We often think that eating disorders start in the mind and cause someone to eat less, but reality is often the other way around.

She was dressed in loose clothing – baggy pants and an oversized hoodie. I suspected that this was not a trendy teenage fashion choice but a way to hide her shrinking body.

It hadn’t worked, though. She had had to try on some clothes when shopping with her mother, and all of the niggling little doubts her mum had had over the past several months had been confirmed.

“It probably started when she said she wanted to be vegetarian,” her mum explained to me, “And I thought it was good that she was taking an interest in her health. But it didn’t stop there. Then it became no fried foods, no takeaways, no desserts. A lot of time on her phone. A lot of time in her room…. We’ve started seeing a psychologist to work on the mental side of things but she’s still not eating much.”

“That’s great that you’ve got a psychologist on board,” I told her, “But in order to be able to do the mental work, we need to have fuel on board. You can’t think clearly when you’re starved. So, we’re going to put a plan in place today to get her eating under supervision.”

A lot of people think that eating disorders like this start in the mind and manifest with food. But curiously, it often goes the other way around.

It usually starts with the innocent-enough idea of being healthier. But for some people, they find that restricting their food intake seems to lessen their anxiety (for now) and gives them a sense of being in control (when often their life feels so out of control in other aspects). And so food restriction becomes this tool to cope.

Over time, their body adapts to less food by silencing their hunger cues (it’s a precious waste of energy for the body to make them hungry if they won’t feed it anyway), which makes it easier to continue eating less.

And the physical changes to the body are phenomenal. People suffering from anorexia nervosa experience a reduction in their brain volume, memory, attention and executive functioning. Levels of the stress hormone cortisol increase and affect the levels of key neurotransmitters serotonin, dopamine and norepinephrine. In fact, the entire brain reward system is altered. This means that the brain may start to view food as anxiety-inducing rather than pleasurable. At the same time, weight loss and food restriction trigger dopamine surges, which make restriction feel rewarding.

This neurobiological shift means they become more anxious, their thinking becomes more rigid, and their day-to-day life gets harder as their thoughts become consumed by food. Anxiety around eating and weight gain become overwhelming. What started as a way to reduce anxiety has now flipped around to cause it.

In this way, a lot of what we think of as typical symptoms of eating disorders are actually the result of the brain’s physiological and psychological adaptations to starvation.

A key experiment in history showed this very clearly: the Minnesota Starvation Experiment.

It was a study conducted as World War II was drawing to a close. Researchers wanted to find the best way to refeed people who had been semi-starved by rationing. So 36 healthy men were recruited to undergo a period of semi-starvation for 24 weeks before being randomized into different refeeding schedules.

It was expected that the men would weight, but the study took a turn as the psychological effects of months of not eating enough became apparent.

Depression, anxiety, irritability and a profound obsession with food took hold. The men would read cookbooks and spend hours discussing recipes. One man took his girlfriend out to dinner just to watch her eat.

Another was in such psychological distress that he intentionally chopped off several fingers of his hand with an axe. Details around this incident are hazy but it brought to the forefront the idea that extreme caloric restriction could actually lead to self-harm.

When the semi-starvation part of the study was over and the refeeding began, the men did not return to normal. They began hoarding food and binge eating. Many reported struggling with their relationship with food for years after the experiment ended.

What began as an experiment to find the best way to refeed people after the war became a window into how disordered eating takes hold.

These men consumed about 1500 kcal during the semi-starvation phase, whilst many of today’s popular diets go as low as 1200 kcal. I believe this shows the dangers of restrictive dieting and how it can cause a cycle of restriction and binge eating that continues for years after the diet is officially over.

When I have a client who is restricting their food intake, I do not expect them to be able to think their way out of what they are doing. At least not at first. They need to eat regularly and restore their brain function before they’re going to be capable of truly undertaking the mental work.

That’s why regular eating is the first nutrition strategy of my S.T.R.I.C.T. Nutrition Method to heal disordered eating. I developed this framework over 10 years of working as a dietitian and I am yet to see it fail.

If you would like a copy of the framework, laid out in cheat sheet format, to guide your consults, just click here. Confidently support your clients as they leave food guilt behind, achieve a natural weight, and unlock lasting food freedom!