It's the meal plan nobody should take on.

A teenage girl in Birmingham, U.K., who has eaten nothing but chicken nuggets for 15 years, is being warned her favourite food is killing her, according to the Daily Mail.

Stacey Irvine, 17, told the newspaper she was hooked on nuggets when her mom brought them home from McDonald's when she was two. Since then, Irvine has never eats fruit or vegetables, and loves to split 20 nuggets with her boyfriend as a pastime.

But it's not all fun in McDonald's Playland. Irvine has breathing problems, anaemia and was recently rushed to the hospital after she collapsed with swollen veins in her tongue. Despite all this, she can't resist temptation.

"I am starting to realise this is really bad for me," she told The Sun.

Single-item food diets like this one can occur when people are addicted to their food habits, want to lose weight, or even test out a theory. As an experiment in 2010, Mark Haub, a professor of human nutrition at Kansas State University, ate nothing but Twinkies for 10 week and lost 27 pounds and almost five points from his body mass index (BMI).

"What I did, it wasn't healthy behaviour and it did lead to health after [with weight and BMI loss]," he told the Huffington Post Canada. "That's the other layer that is complex. There's a difference between healthy eating and healthy outcomes."

Story Continues Below: Here are some other single-item diets people have tried:

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• 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.

Haub also points out that calling out the fast food industry on this isn't always the answer. "The concern is not about what she's eating, it's about what she's not. It's not about saying chicken nuggets are bad -- I think you'd see the same result if she just ate one or a couple types of fruit, or veggies or whole grains. It comes back to trying to teach people to meet needs from a food perspective, versus 'don't eat that, because it's not healthy.'"

Hana Klimczak, a registered dietitian at Nutrition Check in Toronto says, ditching food groups to switch to a single-food diet is the worst option for your body's health.

"I don't believe in labelling foods as 'good' or 'bad,'" Klimczak says. "Balance and moderation is the key to a healthy lifestyle; and all foods fit in moderation." Different foods provide different minerals, she notes, saying that Irvine's nugget-only diet is not benefiting her growing body.

And saying no to that greasy slice of pizza from time to time will help you in the long run.

"Foods deemed as 'junk' will have a lot of added salt, sugar and fat, as well as simple or processed carbohydrates," she says. "The foundation of a healthy lifestyle should include fruits and vegetables, grains, lean proteins, dairy products and small amounts of healthy fats."

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