Do you know what's in your McNuggets? Image Credit: rez-art/iStock/Getty Images

McDonald's started out as a beefy burger joint back in 1948, but the world-famous fast-food chain has been offering another high-protein meat – chicken – since the specially molded McNugget made its debut in 1983.

Perhaps now as iconic as the Big Mac or Quarter Pounder, these tiny deep-fried chunks seem harmless on the surface. And over the years, McDonald's has added dipping sauces that make these bite-sized bits appealing to the taste of just about anyone – adults and kids alike.

White meat from poultry has less saturated fat than red meat. While that might appear to be a healthy advantage, the other ingredients McDonald's adds make its nutritional value questionable. If you're not too squeamish or too chicken to hear all the details, read on to get some nuggets of truth about these little golden treats.

So while McNuggets are "made with 100-percent USDA Grade-A chicken," as McDonalds.com states, there's no way of knowing what percentage of the whole nugget is actually chicken. Christopher Ochner, Ph.D.

THE SUSPECT: McDonald's McNuggets (6-piece serving size, 3.4 oz)

Which is your favorite dipping sauce? Be sure to check the ingredients! Image Credit: fkruger/AdobeStock

THE DETECTIVE: Christopher Ochner, Ph.D.,a research associate at New York Obesity Nutrition Research Center at St. Luke's Roosevelt Hospital Center. Ochner is very familiar with McDonald's menu. A few years ago, he conducted his own "Super Size Me"-type diet experiment: Every day for two months he ate one meal at the fast food restaurant as part of a study.

NUTRITION LABEL: Without sauce: 280 calories, 18 grams fat, 18 grams carbs, 13 grams protein, 0 grams sugar, 540 milligrams sodium, 1 gram dietary fiber.

With barbeque sauce: 330 calories, 18 grams fat, 29 grams carbs, 13 grams protein, 10 grams sugar, 800 milligrams sodium, 1 gram dietary fiber.

LISTED INGREDIENTS: Chicken McNuggets: White Boneless Chicken, Water, Food Starch-Modified, Salt, Seasoning (Autolyzed Yeast Extract, Salt, Wheat Starch, Natural Flavoring [Botanical Source], Safflower Oil, Dextrose, Citric Acid), Sodium Phosphates, Natural Flavor (Botanical Source). Battered and Breaded with: Water, Enriched Flour (Bleached Wheat Flour, Niacin, Reduced Iron, Thiamin Mononitrate, Riboflavin, Folic Acid), Yellow Corn Flour, Bleached Wheat Flour, Food Starch-Modified, Salt, Leavening (Baking Soda, Sodium Acid Pyrophosphate, Sodium Aluminum Phosphate, Monocalcium Phosphate, Calcium Lactate), Spices, Wheat Starch, Dextrose, Corn Starch. Contains: Wheat.

*Prepared in vegetable oil (Canola Oil, Corn Oil, Soybean Oil, Hydrogenated Soybean Oil with TBHQ and Citric Acid added to preserve freshness). Dimethylpolysiloxane added as an antifoaming agent. Prepared in vegetable oil (Canola oil, corn oil, soybean oil, hydrogenated soybean oil with TBHQ and citric acid added to preserve freshness). Dimethylpolysiloxane added as an antifoaming agent.

Tangy Barbeque Sauce: High-fructose corn syrup, water, tomato paste, grape vinegar, distilled vinegar, salt, soy sauce (water, wheat, soybeans, salt), food starch-modified, spices, dextrose, soybean oil, natural smoke flavor (plant source), xanthan gum, caramel color, garlic powder, cellulose gum, dried chili peppers, malic acid, natural flavor (fruit and vegetable source), onion powder, sodium benzoate (preservative), succinic acid. Allergens: Wheat and Soy.

How Much Actual Chicken Is in McDonald's McNuggets?

With over 30 ingredients listed, it's easy to see how chicken may actually play a minor role in McDonald's McNuggets. Image Credit: buhanovskiy/AdobeStock

It's always good to see the actual food listed as the first ingredient —white boneless chicken.

"The first item on the nutrition label means the food contains more of that one item than any other single ingredient," said Ochner. So while McNuggets are "made with 100 percent USDA Grade A chicken," as McDonalds.com states (note it says "made with" not "made of," Ochner pointed out), there's no way of knowing what percentage of the whole nugget is actually chicken.

"White boneless chicken is almost a pure protein, boasting a phenomenal 0.2 protein (grams): kcal ratio with less than 20 percent fat," explained Ochner. "McNuggets, on the other hand, have a very mediocre 0.046 protein:kcal ratio with 57 percent of kcal from fat. This seems to suggest that the other ingredients, besides chicken, are the primary driver of the macro-nutrient profile," he said.

With over 30 ingredients listed, it's easy to see how chicken may actually play a minor role in this dish. It may also explain why the chicken seemed to disappear in an alarming YouTube time-lapse video shot in March 2013 (see link below in the "Resources" section of this article), showing McNuggets left at room temperature over a two-day period.

When Ochner performed this experiment himself (he left them in the fridge for 10 days), the so-called chicken in the McNuggets pieces remained intact. This disturbing mystery remains unsolved.

Did You Know That McNuggets Are 57 Percent Fat?

Holy cow, er, chicken: McNuggets are 57 percent fat!

One big fat contributor may be hydrogenated soybean oil, which is loaded with trans fats. "I don't suspect there is a ton of it in there because the saturated fat is relatively low," Ocher said. "However, some of it is almost certainly still partially hydrogenated, which also helps with preservation."

What the Heck Is TBHQ (Tertiary Butylhydroquinone) and Why Is It In McNuggets?

McNuggets look so innocent, sitting on this slate gray table. Did you know they contain TBHQ, linked to nausea, ADHD and DNA damage? Image Credit: rez-art/iStock/Getty Images

You might recognize this hard-to-pronounce ingredient (hence the acronym) from our "What's Really Inside those McDonald's French Fries" exposé (see link below in the "Resources" section).

This powerful petroleum-based preservative (which is also found in varnishes, lacquers, pesticide products, cosmetics, and perfumes) may be used to help the chicken and other ingredients maintain their distinct shapes.

Eaten in high doses – and it's hard to determine exactly how much is added to McNuggets – this chemical can be toxic.

Possible side effects include nausea, delirium, collapse, tinnitus (ringing in the ears) and vomiting. Some studies have linked it to hyperactivity in kids, asthma, rhinitis, dermatitis, aggravated ADHD symptoms and restlessness.

Furthermore, animal studies have reported that it may cause DNA damage. This mounting scientific evidence was enough that McDonald's entirely removed this bad-news ingredient from the version of their McNuggets sold in the United Kingdom.

Oh America, can we please take a cue from the British on this one with regard to concern for our citizens' health?

The British Won't Stand for Dimethylpolysiloxane, But Americans Eat It in Their McNuggets

Here's another ingredient the British won't stand for in their McNuggets: Dimethylpolysiloxane. But Americans are still eating it.

This silicone-based anti-foaming agent has been removed from the United Kingdom's McNugget ingredient list – and with good reason.

While McDonalds.com admits that "a drop of an additive in vegetable oil is added to simply prevent foaming on the surface that naturally occurs in cooking," what it isn't telling you is that this same chemical is found in silly putty, contact lenses, medical devices, shampoos, lubricating oils, heat-resistant tiles and breast implants.

"No studies have suggested any toxic effects," Ochner said, "but it's definitely gross to think about."

Autolyzed Yeast Extract, a.k.a. MSG in Your McNuggets

Even this kid is skeptical of McNuggets. He doesn't want to eat Dimethylpolysiloxane. Image Credit: KidStock/Blend Images/Getty Images

This sneaky ingredient -- Autolyzed Yeast Extract in the McNuggets' seasoning -- contains monosodium glutamate (also known as MSG) which allows McDonald's to create the illusion that you're getting more protein with each bite than you actually are.

This cheap, flavor-enhancing filler is FDA-approved (even though approximately 15 percent of Americans have MSG sensitivity and suffer from headaches, nausea, and heart palpitations when they consume it).

That said, even if you're not one of the people affected with MSG sensitivity, including MSG in the McNuggets recipe is still a devious way of cheating you the consumer out of real chicken (seriously, how much poultry is in those things?!), cutting corners on costs and avoiding listing the word "MSG" on the label.

Those McNuggets Contain Sodium Aluminum Phosphate Too

Key word here is "aluminum." You know, the silvery metallic element you use to line your oven rack before baking or roasting?

Ochner explained that this ingredient is synthetically produced from aluminum as well as phosphoric acid and sodium hydroxide.

While this all sounds highly unappetizing, its function isn't to entice you but rather to act as a leavening agent that's often used in flour mixes, like the breaded part of the McNugget.

In terms of its safety, the FDA allows a daily aluminum intake that ranges from 10 to 100 mg, so as long as McDonald's stays within that range, it's within the legally acceptable limit.

The Final Verdict on McDonald's Chicken McNuggets

McNuggets are McNasty.