"In 2010, I went on a diet. Little did I know in five years, it would end my marriage."

Trigger warning: This story deals with eating disorders and exercise addiction. 

Even if I’d wanted to stop, I couldn’t have.

Pumping my arms, I pounded the pavement, enjoying the sensation of my muscles burning, of the sweat trickling down my back. I gritted my teeth, dug deep and just kept on going.

When I finally slowed down and glanced at my watch, a satisfied smile spread across my face. I had been running for six hours straight.

I wasn’t competing in a marathon or taking part in some kind of charity event. This was simply my daily work out. The same way you might go to a Saturday morning Body Pump class or take a 30-minute walk on your lunch break, I would run for six hours.

Every single day.

It had started as a form of stress relief when I was just 10 years old. Dad was an alcoholic and as a result my mum was running the family business single-handedly.

Whenever things at home were tense – which was often – I put on my runners and bolted out the door.

We had a big property and plenty of land. I ran laps of the house until it was time for dinner or school or bed.

But somewhere along the line, my healthy habit developed into an obsessive need to control. My runs got longer and longer.

I grew tall and developed breasts early. The discomfort I felt in my own body fuelled my work outs – and was the reason why I began to scrutinise everything that went on my plate.

Soon my diet consisted of nothing more than some rice porridge for breakfast and a few vegetables of an evening. I don’t know how that amount of food fuelled my six hours runs, but somehow it did. My chest ached and I longed to stop – but I wouldn’t, couldn’t let myself.

LISTEN:We all have different coping mechanisms to ensure control. We look at both not eating, and over-eating, on The Well. Post continues after audio…

My weight dropped dramatically. It wasn’t long before I was diagnosed with an Eating Disorder Not Otherwise Specified (EDNOS) and admitted to a clinic. The nurses there told me I wasn’t allowed to go outside to exercise, so I ran laps around the pool table for two hours a night while everyone was asleep.

Over the next few years, I was in and out of clinics and treatment centres, never really getting any better.

It was during one of these stays that I met Steve* who was suffering from depression. We connected instantly and when we left the centre, we moved in together, marrying a year later.

Since I was 10, people had been telling me to eat. That I needed food. The more the better in my case.

And so, relaxing into my new found happiness, I took that advice for the very first time.

The trouble was, I knew nothing about nutrition. All I knew about was high calorie food that would make me gain the weight the doctors so desperately wanted me to – ice cream, cakes, cookies. I binged on these foods until my stomach hurt. My body grew rounder, but none of it was healthy.

One day, I looked at myself in the mirror and decided to change tack.

Through books and websites, I taught myself about nutrition. Honestly, to this day I believe I could give a qualified dietician a run for their money with everything I know about micros, macros, calories and carbs.

Armed with this knowledge, I started my new “diet”.

Eating before 4pm was out – my own version of the intermittent fasting trend that people would rave about years later. Carbs were ditched – without those in my body, I’d burn through fat faster on my runs. Junk food, sugar, alcohol and oils – none of these things would touch my lips ever again (not that alcohol ever had in my entire life.) My eating would be perfectly clean, every single day, without fail.

My weight began dropping again, my list of “allowed” foods ever-shrinking.

It wasn’t long before the cracks began to show in my marriage. We couldn’t go out for dinner or even a coffee together because I refused to eat or drink anything I hadn’t prepared and calorie-counted myself. I even refused to eat in the same room as my husband – the food I did eat was my comfort and I wanted to be alone with it.

I was still exercising six hours a day too, fitting in running and cycling around my job at Macca’s (oh, the irony). The time I spent with Steve was scarce. Even when we were together I was preoccupied.

Food and exercise had become the entire focus of my life. I’d kidded myself into believing this was healthy, that I was all about nutrition. But my rigid adherence to my so-called diet had become an all-consuming obsession.

And it had come at a huge cost – my marriage was breaking down. I felt utterly powerless to stop it. I was too scared to divert energy anywhere else.

I wasn’t even that shocked when Steve left.

Now, I’m 28 and I live alone. For 17 years, I haven’t eaten a meal that I haven’t weighed, prepared and cooked myself. Recently I agreed to go out for a coffee with my friend, but at the last moment, I panicked and switched my order to a glass of water.

I never have a cheat meal, never skip a work out. Even if I’m sick, I still exercise. I am so versed in the nutritional content of everything I eat, I don’t need to log it. It’s all safely added up in my head.

I want people to know – my lifestyle isn’t healthy. I don’t want to receive praise for my “discipline”. This is a disease and it’s built a prison around me. I just really hope one day I can break out.

If you or a loved one is suffering with an eating disorder, Mamamia urges you to contact The Butterfly Foundation. You can also receive crisis support by phoning Lifeline on 13 11 14.