Slideshow: Busted: Popular Diet Myths

Put this diet myth to bed. There's no conclusive proof that late-night meals cause you to put on weight. What we do know is that too many calories cause weight gain, and many night eaters do tend to overeat and choose high-calorie foods. Still, eating right before bedtime can lead to heartburn and indigestion. So try to stick to regular -- and earlier -- mealtimes.

Table sugar, agave, honey, and high-fructose corn syrup contribute calories (between 48 and 64 a tablespoon). So far, research shows that our bodies absorb added sugars like high-fructose corn syrup and table sugar in a similar way. Instead of avoiding one particular kind of sugar, try to limit added sugars of any kind, like those in soda, candy, and other sweets.

This is a recently debunked diet myth. Coffee, when consumed in moderation (2 to 3 cups daily), is a safe part of a healthy diet and contributes antioxidant phytochemicals. In fact, research suggests coffee may help reduce the risk of type 2 diabetes, gallstones, Parkinson's disease, even some cancers. Keep coffee calories in check, though. Steer clear of trimmings like cream, sugar, and flavored syrups.

Your body needs three nutrients to thrive: protein, carbohydrates, and fats. Yes, fats! Good-for-you fats found in foods like nuts, seeds, fish, avocado, olives, and low-fat dairy give you energy, help rebuild cells, and produce needed hormones. The fats to limit or avoid are saturated and trans fats, found in foods like butter, high-fat dairy, red meat, and many processed foods.

Think switching to sea salt will save sodium? Sorry, that's a diet myth, too. By weight, gourmet salts have about the same sodium as plain old table salt. Add flavor with pepper, herbs, and spices instead. Besides, we get about 75% of our total salt intake from processed and prepared foods (not the salt shaker) like soups, condiments, mixes, cheeses, and canned goods.

There's no doubt water is vital for your body -- but a weight loss aid? Not really. If drinking water keeps you away from high-calorie drinks, it can certainly help you lose weight. But adding more water to your diet, without changing anything else, makes no difference in lowering the numbers on your scale.

We know whole grains are good for us because they're packed with fiber, vitamins, minerals, and phytochemicals. That doesn't mean you need to ditch all processed grains. At times, like when your body is recovering from an intestinal bug, refined grains may be necessary. And some processed grains are fortified with folic acid. While whole grains are the healthier choice, you can make room for some fortified processed grains, too.

This myth is so common it seems impossible that it isn't true. Yet most research shows sugar doesn't make all kids hyperactive. So why do kids bounce off the walls at birthday parties? It's not the cake; it's probably the exciting environment. Still, pay attention to how much sugar your kids eat. Eating too many sweets leaves little room for healthier food.

Everyone knows an athlete needs tons of protein to build strength and muscle, right? Well, not exactly. Most American diets provide plenty of protein even for athletes. The real secret to boosting athletic strength and muscle is to get enough calories, focus on intense training, and get a carb- and protein-containing snack (such as nonfat chocolate milk) soon after an intense muscle workout. Special powders, bars, and supplements need not apply!

Worried that your love of cake or candy will lead to diabetes? Stop fretting about this diet myth. If you don't have diabetes, eating sugar won't cause you to get the disease. What does raise your diabetes risk, however, is being overweight and inactive. So do your body a favor: Cut back on the empty, sugary calories, and get moving!

Stop believing this diet myth. Not all carbohydrates are bad for you. But it seems like people lose weight on low-carbohydrate diets, right? Those diets almost always restrict calories, too, and fewer calories add up to fewer pounds over time no matter how many of your calories come from fat, protein, or carbohydrates.

• First, if it sounds too good to be true, it almost definitely is.
• Second, ask yourself, "Who says so?" Is the person making the claim biased? Are they trying to sell a product? Is the information based on just one small study?
• There's no secret ingredient to weight loss or maintenance. We've known for a long time that eating right and exercising are what matters.