Thirty-three-year-old Claire Simmons, of Notting Hill in London, is in a monogamous relationship with a dangerous partner: pizza.
For the last 31 years of her life, she has eaten nothing but plain cheese pizza for every single meal, she tells the Sun. And now, her doctors say that Simmons' monotonous diet could kill her.
Simmons says she exercises and drinks plenty of water. The problem is that her limited diet -- the result of a mental illness known as Selective Eating Disorder -- doesn't provide all the minerals and vitamins she needs for solid health.
Simmons exposed her difficult story to the public after reading the story of Stacey Irvine, sometimes called "Chicken Nugget Girl," a fellow Brit who was hospitalized after eating only chicken nuggets for a decade and a half.
This fall also brought to light the story of Jonathan McGowan, a British man who, for the past 30 years, has refused to eat any meat except roadkill. The BBC has even aired documentary-based multiple series on the topic of extremely picky eaters. Could there be something in English water that gives its drinkers Selective Eating Disorder? Maybe -- though it seems even more likely that there's something about English tabloids that helps these stories find an eager public.
Here are 10 other foods that people have tried -- most often, with less than fantastic results -- to eat to the exclusion of all others:
Loading Slideshow
Twinkies
Nutrition professor Dr. Mark Haub undertook an experiment on himself in 2010 -- he ate only Twinkies, along with other junk foods like chips and cookies, for 10 weeks. In that time, he lost 27 pounds, and his body mass index (BMI) went from 28.8 (almost obese) to 24.9 (normal). As <a href="http://www.huffingtonpost.com/david-katz-md/chewing-on-the-twinkie-di_b_782678.html" target="_hplink">Huffington Post blogger Dr. David Katz wrote</a>, "The Twinkie diet was a dreadful diet. But it was, nonetheless, a diet in the conventional sense, meaning it was calorie-restricted."
Subway
As most anyone who watched television in 2000 knows, Jared Fogle lost 245 pounds eating Subway sandwiches, as well as started to exercise by walking. He cut his daily consumption from 10,000 calories down to 2,000, eating two subs a day, along with baked potato chips and diet soda.
<em>Fred DeLuca, President and founder of sandwich maker Subway, is shown here.</em>
Cottage Cheese
One of the few single-item foods 'allowed" in the 3 Day Diet fad is cottage cheese. It's often taken even further by people on cleanses, who eat only the protein-rich food as their main source of nutrients for up to two weeks. While it does supply carbohydrates and the aforementioned protein, cottage cheese is also high in sodium and missed out on plenty of vitamins.
Grapefruit
Grapefruit has long been known as a diet food, and it's likely thanks to the Grapefruit Diet, a fad option that's been around since the 1930s. The premise is that, when consumed, grapefruit triggers a fat burning mechanism that helps rid the body of anything else you may have eaten that day. It's not scientifically proven to work, though grapefruit can be part of a healthy diet, thanks to its high levels of vitamin C and anitoxidant lycopene.
Potatoes
In 2010, Chris Voigt began a two-month, all-potato diet that lead to a 21-pound weight loss and lowered his cholesterol. It didn't hurt, of course, that Voigt is the head of the Washington State Potato Commission and managed to get great publicity for his favoured food through the plan, but <a href="http://today.msnbc.msn.com/id/40424707/ns/today-today_health/t/days-nothing-spuds-leaves-advocate-lbs-lighter/#.TyGs58Vzkno" target="_hplink">he did claim he used only seasonings and oil to accompany the taters</a>. Considering all of their many uses in cooking, it seems a bit of a waste.
Eggs
Charles Saatchi, husband of famed British chef Nigella Lawson, apparently <a href="http://www.telegraph.co.uk/news/celebritynews/3163492/Charles-Saatchi-ends-nine-eggs-a-day-diet-says-wife-Nigella-Lawson.html" target="_hplink">subsisted only on eggs, with the occasional piece of toast, for nine months</a> -- and lost over 60 pounds in the process. Adrian Brody apparently took on the same regime to lose 30 pounds for his role in "The Pianist." While there's plenty to be had with eggs, there's also lots of cholesterol and saturated fats -- not to mention the bloating, bad breath, and uh, other effects.
Baked Beans
Baked beans may more often be seen as a side dish for tacos and the like, but one man decided to make it his mainstay for over a year. After finding out he was at risk for bowel cancer,<a href="http://www.thatsfit.com/2008/04/13/man-loses-140-pounds-on-baked-bean-diet/" target="_hplink"> Neil King stopped drinking alcohol and started eating six cans of beans a day</a>, accompanied by rice or potatoes. He lost 140 pounds in a year.
McDonald's
You'd think anyone who watched Morgan Spurlock's "Supersize Me" in 2004 would never even think about an all-McDonald's diet -- espcially after seeing what<a href="http://www.youtube.com/watch?v=4wmac-INoXg" target="_hplink"> French fries<em> really </em>look like after a month</a> (hint: the same). On top of this, Spurlock's journey of eating from McDonald's menu for a month made him gain 20 pounds, lose his sex drive and increase his body fat. <br>The McRunner, however, had a different outlook. Last year, a <a href="http://www.suntimes.com/news/4212103-418/mcrunner-trains-for-marathon-by-eating-only-mcdonalds.html" target="_hplink">woman only ate McDonald's to raise money for the Ronald McDonald House Charities in Phoenix </a>and train for a marathon at the same time -- balancing out exercise and eating "healthier" options from the chain.
Cabbage Soup
Now, nobody wants to smell like they're on the cabbage soup diet, but for some people it's an easy way to kick off a new diet plan. This diet is part of a low-calorie, low-fat and high-fibre diet and even claims to help people lose 10 pounds in seven days.
Bacon
Sure, <a href="http://www.huffingtonpost.com/2012/01/25/bacon-nosebleed_n_1231092.html" target="_hplink">we think bacon can cure nosebleeds</a>, but can it also make up a healthy diet? One San Diego <a href="http://blog.rifftrax.com/2009/03/02/bacon-stupidity-the-true-story/" target="_hplink">man put that to the test in 2009</a>. Mike Nelson had the intention of eating bacon for a full month, but ended up stopping just shy of the 30 days. He claims to have enjoyed it (who wouldn't?), but no health benefits were in any way revealed.
Loading comments… 
Posted: 02/21/12 06:23 PM ET | Updated: 02/22/12 10:05 AM ET