But if the vast majority of Americans were truly eating healthy, we would not have two-thirds of the population overweight, nor would we be facing epidemics of diet-related chronic diseases like cancer, heart disease and type 2 diabetes.

So what is going on?

Many Americans are seriously confused about what is truly a health food, and this is partly the result of clever and deceptive marketing that makes junk foods and synthetic substances, like artificial sweeteners, appear healthy. Two of the seven fattening "health foods" listed by MSNBC were those that contain artificial sweeteners, such as diet soda. And perhaps no other class of foods deserves the gold medal for "healthy foods" that can make you fat than diet foods themselves.

Diet Foods May Hinder Your Weight Loss Goals

Stocking your pantry with diet foods is one of the surest ways to lose the battle of the bulge, and this is largely due to the fact that they're loaded with artificial sweeteners. Substances like Splenda and aspartame may have zero calories, but your body isn't fooled. When it gets a "sweet" taste, it expects calories to follow, and when this doesn't occur it leads to distortions in your biochemistry that may actually lead to weight gain.

As far as "sweetness satisfaction" in your brain is concerned, it can tell the difference between a real sugar and an artificial one, even if your conscious mind cannot. Artificial sweeteners tend to trigger more communication in the brain's pleasure center, yet at the same time provide less actual satisfaction.

So when you consume artificial sweeteners, your body craves more of it and real sugar, because your brain is not satisfied at a cellular level by the sugar imposter!

This supports and explains the growing body of research that tells us artificial sweetener use may ruin your body's ability to control calories, thus boosting your inclination to overindulge. As a matter of fact, it's been shown that diet soft drinks can double your risk of obesity!

Nearly a decade ago, studies were already revealing that artificial sweeteners may:

• Stimulate your appetite
• Increase carbohydrate cravings
• Stimulate fat storage and weight gain

Unfortunately, most public health agencies and nutritionists in the United States still recommend these toxic artificial sweeteners as an acceptable alternative to sugar.

Pretzels, Cereal and Veggie Chips: Weight Loss No-Nos?

Many dieters snack on pretzels and "healthy" veggie chips in lieu of other salty snacks like potato chips, believing them to be healthier alternatives. Well, neither is a wise choice. In the case of pretzels, you may as well be dipping a spoon straight into a bowl of sugar, as that's precisely the way your body responds to this refined carbohydrate snack.

Don't be fooled by the fact that they're "fat-free" -- it's the carbs that are the culprit.

Your body prefers the carbohydrates in vegetables rather than grains because it slows the conversion to simple sugars like glucose, and decreases your insulin level. Grain carbohydrates, like those in pretzels, will increase your insulin levels and interfere with your ability to burn fat – which is the last thing you want if you're trying to lose weight.

This is precisely why cereals, whether high-fiber, whole-grain or not, are not a food you want to eat if you're concerned about your weight. If they contain sugar, that will tend to increase your insulin levels even more … but even "healthy" sugarless cereals are an oxymoron, since grains rapidly break down to sugar in your body, stimulating insulin production and encouraging weight gain.

Veggie chips, meanwhile, are nothing more than glorified potato chips. Most are made from corn flour or potato as a base and have only veggie powder or puree added in. Not only are most of the vitamins in veggies therefore NOT in veggie chips, but these snacks are then either fried or baked at high temperatures.

When carbohydrate-rich foods like chips are cooked at high temperatures, acrylamide -- a tasteless, invisible chemical byproduct -- is formed.

Animal studies have shown that exposure to acrylamide increases the risk of several types of cancer, and the International Agency for Research on Cancer considers acrylamide a "probable human carcinogen." It has also been linked to nerve damage and other neurotoxic effects, including neurological problems in workers handling the substance.

While this chemical can be formed in many foods when they're heated to a temperature above 120 degrees Celsius (248 degrees Fahrenheit), French fries and potato chips are the biggest offenders.

So whether they're laced with veggie powder or not, veggie chips are not a smart food choice. A far healthier alternative, as MSNBC noted, would be to chop up some fresh kale and toss it with some olive oil and natural salt, then bake it in your oven until crispy (homemade kale chips are also a favorite of "soul surfer" Bethany Hamilton).

Frozen Yogurt and Turkey Burgers Should be Avoided Too?

The remaining two items on the MSNBC list can be good or bad for you, depending on a few factors. With frozen yogurt, most commercial varieties will contain too much sugar to be healthy in an effort to improve the flavor and increase their sales. Remember, in most cases you gain weight because of an excess of carbohydrates like sugar -- not because of fat -- so even if your frozen yogurt is low-fat, it can make you gain weight since it is virtually guaranteed to be loaded with sugar.

That said, yogurt that is made from raw organic milk, and which you use to make homemade frozen yogurt that is only minimally sweetened, could be a healthy treat to eat on occasion.

As for turkey burgers, the problem is not so much about their high saturated fat content if made from dark meat or skin, as MSNBC suggested. Rather, the reason to avoid most turkey burgers is due to the source of the turkey, which in most commercial varieties will be a confined animal feeding operation (CAFO). Turkey from this source will typically contain hormones, pesticides and antibiotics, and will be fed genetically modified grains -- all of which you're better off avoiding.

It's very possible to make a healthy turkey burger, though, you just need to get the meat from a trustworthy local source -- and then skip the bun.

What's the Number One Weight Gain Culprit That Wasn't Mentioned?

Fructose!

This sugar is often deemed a "healthy" type because it's the kind that exists naturally in fruit. And if you were to only eat fructose in a piece of fruit or two a day, you'd probably be just fine.

The central issue is that fructose is now used in virtually all processed foods (whether you'd suspect the food would contain a sweetener or not). Case in point: the number one source of calories in the United States is high fructose corn syrup (HFCS) in the form of soda!

Again, if you're able to keep your total fructose consumption below 25 grams per day then it's not typically going to cause you or your family any major health issues. Unfortunately, while this is theoretically possible, precious few people are actually doing that. Cutting out a few desserts will not make a big difference if you're still eating a "standard American diet" -- I've previously written about how various foods and beverages contain far more sugar than a glazed doughnut.

Because of the prevalence of HFCS in foods and beverages, the average person now consumes one-third of a pound of sugar EVERY DAY, which is five ounces or 150 grams, half of which is fructose. That's 300 percent more than the amount that will trigger biochemical havoc.

Remember that is the AVERAGE; many actually consume more than twice that amount.

Evidence is mounting that excess sugar, and fructose in particular, is the primary factor in the obesity epidemic, so it's definitely a food you want to avoid if you want to lose weight. Does this mean you need to avoid fruit too? As you can see in this table, some fruits are very high in fructose, so munching indiscriminately could set you back.

If you struggle with insulin resistance, metabolic syndrome, diabetes, high blood pressure or high cholesterol -- all of which typically go hand in hand with obesity and overweight -- you'll need to be particularly careful about limiting your fructose from fruit to 15 grams per day or less.

Granted, whole fruits, even though they contain fructose, are not nearly as problematic as fructose from added sugars. One of the reasons for this is believed to be because whole fruits contain high amounts of natural antioxidants, as well as other synergistic compounds that may help counter the detrimental effects of fructose.

But very large portions of fruit daily cannot be recommended for most overweight people.

One Final Weight Loss "Secret"

Maintaining an optimal weight is not only about knowing which foods to avoid, it's knowing which foods to eat.

This is the beauty of eating according to your nutritional type.

Typically, finding your optimal diet involves shifting the ratio of proteins, fats, and carbohydrates, once you have determined what types of food your body is designed to eat. Optimal health may actually have less to do with the type of food you are eating, but with the relative percentage of each food you consume.

If you are eating right for your nutritional type, your meal should give you increased energy, noticeable improvements in mental capacity and emotional well-being and should leave you feeling satisfied for several hours.

At the end of the day, it is largely your consumption of carbohydrates, whether in the form of grains (including whole grains) and sugars (especially fructose), will determine whether or not you're able to manage your weight and maintain optimal health. This, combined with eating right for your nutritional type, can be the change you've been looking for if you are currently overweight and/or your health is suffering.