The 19-year-old from Wrexham, Wales, hasn't eaten a proper meal since she was two years old and gags if she puts anything other than a plain pizza slice in her mouth.
Sophie has lived on a diet of cheese and tomato pizza since she was 11 as even a slice of pepperoni is enough to turn her stomach.
The teen suffers from a bizarre condition called Selective Eating Disorder (SED), which means she has a phobia of almost all foods, leaving her petrified to try new foods.
Sophie's condition began when she was two after suffering from stomach bug, Gastronentritus.
Following the illness, Sophie began to fear food and could only manage cheesy pasta, chips and lemon curd sandwiches before moving onto pizza when she was 11.
Sophie has lived on a diet of pizza ever since, sometimes eating up to three a day.
The performing arts student says: "I love pizza, each brand offers a new flavour, but it's all the same food so I don't have to try new foods.
"I began selective eating when I was two. My mum said after I was ill, I became frightened to eat, I thought food had caused my illness.
"I began eating cheesy pasta or chips and then moved onto lemon curd sandwiches, which I ate every day for four years.
I plucked up the courage to try pizza when I was 11 and i've eaten it every day since, sometimes I have it for breakfast, lunch and dinner.
"If I don't have chance to eat pizza before I start college I go all day without eating, because there's nothing else I can eat, so I wait until I get home and have one or sometimes two pizzas.
"It has to be cheese and tomato and it has to be hot, I can't eat it cold and I can't have any toppings on it."
Sophie hasn't touched a fruit or vegetable in years and the thought of eating a varied meal terrifies her.
She says she occassionally eats pasta and chips or sometimes a packet of cheese and onion crisps but she eats pizza so often even this slight variation in her diet makes her feel sick:
"The thought of trying other foods makes me very anxious, I feel sick and really clam up. The taste the texture even the smell of some foods can make me gag.
A lot of people think I'm just a picky eater but SED is a phobia. Asking me to try new foods is like asking someone who hates spiders to hold one. The more ingredients a food has in it the more terrifying I find it, a full English breakfast would be my worst nightmare, I feel really sick just looking at one.
Sophie visited a specialist two years ago who tried to encourage her to try new foods.
But Sophie says while this helped reduce some of the anxiety she felt about trying new foods, she is still unable to add variety to her diet and has continued to live on pizza:
"My favourite pizza is Pizza Express but I also like Dominos and supermarket pizzas, I eat all brands of pizza as long as it's cheese and tomato.
"I can have a pizza from ASDA and it will taste really cheesy and then have one from Pizza Express which has more flavour from the tomatoes. But if a pizza had any other ingredient on it, I wouldn't be able to eat it. I wouldn't even be able to pick it off.
"Selective eating disorder makes me feel quite low, I get depressed at times and going out for meals with family or friends is a nightmare, so I often don't go.
"I know my diet isn't doing my health any good and I'd really love to eat normally but it's really hard to change my diet after eating like this for so long."
A spokesman from eating disorder charity Beat said: "Selective eating disorder when someone focuses on one particular type of food, usually high-fat or carbohydrate, is generally a sign that there are deep emotional issues at work and they may feel their world is not in control. These issues must be addressed in order to overcome the illness.
"In the past selective eaters were generally thought to be young boys who survived on food like chips and sandwiches alone but recent research shows more adults seeking help for this illness.
"It can be very isolating with the individual not wishing to engage in social situations where food is involved. Research also shows that often people are genetically hard-wired in a way that makes them vulnerable to developing an eating disorders along with the various societal and cultural factors that can trigger their development."
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Words: Lianne Ryan at Caters