15 Worst Diet Tips, Ever!

You know you can't believe everything you read. And still, you haven't eaten an egg yolk since the 90s, and you can't touch a French fry without being saddled with guilt. Oh, and don't even get us started on the whole don't-eat-after-8-PM-or-else mentality. Let's set the record straight once and for all by calling out these 15 worst diet tips-and offering up smart food rules to follow instead.

1. Fat makes you fat.
Why that's BS: It depends on the type of fats you're eating, says Tricia Psota, RD, a nutritionist based in Washington D.C. "Fats in chips, cookies, and greasy foods can increase cholesterol and your risk for certain diseases. But good fats, like nuts, avocados, and salmon, protect your heart and support your overall health." And when paired with a healthy diet, the right fats can help keep you from being, well, fat, adds Sharon Palmer, RD, author of The Plant-Powered Diet.

TRY THIS: Healthy Fats That Make You Skinny

2. Stop snacking to lose weight.
Why that's BS: Eating in small, frequent amounts is a great way to curb hunger, control portion sizes, and make better nutritional choices, says Mike Clancy, CDN, a personal trainer at David Barton's Gym in New York City. "Smarter snacks like nuts, fruits, and yogurt will keep your energy levels high throughout the day."

3. A calorie is a calorie-and you should count them.
Why that's BS: "Not all calories are the same," says Clancy. "The type of calories, the timing of the calories, and the quality of the calories can significantly alter the effect of the calories on the body," he says. "Food creates reactions within our bodies and the type of food you eat is an important component in diets."

For example, 50 calories of an apple will cause a different internal reaction than 50 calories of cheesecake, says Clancy. "The quality of the calories is also important because the chemicals, hormones, and general byproducts that are found within processed food effects the absorption of real nutrients." Quality calories are nutrient dense, like spinach. Calories that don't contain any nutrients-also known as "empty" calories-are like the ones found in French fries.

Bottom line: Calories are important for understanding portion control, but they're not the only factor in good nutrition, says Clancy.

PLUS: 10 Calorie-Burning Myths, Busted

4. Load up on protein.
Why that's BS: Sorry, caveman lovers: eating lots of protein is not the key to healthy weight loss. Why? The body needs three macronutrients: Protein, carbohydrates, and fat, says Rania Batayneh, MPH, a nutritionist and author of the forthcoming The One One One Diet (published by Rodale, which also publishes Prevention), and focusing exclusively on protein for weight loss makes no sense. "You not only deprive your body of fiber and other antioxidants found in healthy carbohydrates-whole grains, fruits, and veggies-but you also run the risk of eating too much fat in your diet which can lead to high cholesterol and triglycerides."

5. You burn more calories working out on an empty stomach.
Why that's BS: Working out with or without food in your stomach doesn't affect calorie burn-but skipping meals before sweat sessions may result in muscle loss, finds a study published in the Strength and Conditioning Journal. And before you settle for a sports drink, know this: While a quick sip of sugar energizes your muscles, the drink's other artificial additives can be harmful to your health, says Sanda Moldovan, DDS, MS, CNS, a diplomat of the American Academy of Periodontology.

Instead, go for naturally sweet fruit, like bananas, peaches, and mangos before your sweat session. Or try an ounce of dark chocolate for the same caffeine fix you get from a half cup of coffee. "Chocolate also contains feel-good substances, called neurotransmitters, which are the same release during a 'runner's high,' " says Moldovan.

6. Eat every 2 hours to rev your metabolism.
Why that's BS: Going four or five (or even eight!) hours between normally-sized meals will not make your metabolism slow down, says Monica Reinagel, MS, a nutritionist based in Baltimore. "Eating more frequently may help stave off hunger, which can help you fight temptation. But if you want to do this, you have to be careful to keep your meals and snacks really small," she says. "Otherwise, eating every 2 hours can simply lead to taking in too many calories over the course of the day."

TRY THIS: You can help your body burn more calories by incorporating these Foods That Speed Up Metabolism into your daily meals.

7. Swear off forbidden foods.
Why that's BS: "We tend to be in 'all or nothing' mode when we diet and never seem to find a middle ground," says Batayneh. "You have to realize that you can't have pizza, French fries, and chocolate cake all in the same day, but-with careful planning-you can enjoy these foods when they are presented to you. Just don't go for seconds and share if you can." In fact, research shows that moderately indulging in "forbidden foods" is what keeps people from bingeing on the stuff.

8. Drink your fruits and veggies.
Why that's BS: While shoving five servings of fruits and vegetables into a juicer seems like a simple and efficient way to get the daily recommended amounts, it comes at a cost, says Batayneh. "Unfortunately, juicing fruits and vegetables removes one of their most valuable components: fiber. Found in the pulp, skin and seeds, fiber's list of benefits ranges from filling you up to maintaining stable blood sugar levels." If you're juicing more sweet stuff (fruit and carrots) than green stuff you're also going to seriously spike your sugar. (Some juicers allow you to keep in the pulp, so that's another option.)

TRY INSTEAD: 6 Drinks That Shrink Your Belly

9. Eat as few calories as possible.
Why that's BS: "Ugh, awful tip," says Chrissy Carroll, MPH, RD, founder of Inspired Wellness Solutions, LLC. "When you cut your calories too low, your body acts as if it's going into starvation mode and your metabolism slows down." But a reasonable goal, adds Carroll, is to cut approximately 500 calories each day through diet and exercise, which will lead to a healthy rate of weight loss of one pound per week.

10. Say no to nuts.
Why that's BS: Yes, nuts are calorie dense, but that doesn't mean they can't-or shouldn't-easily be incorporated into a healthy diet when eaten in proper portions, says Carroll. A 2011 study in the Journal of The American College of Nutrition backs this up, with researchers finding that nut consumers, especially tree-nut consumers (think almonds, pecans and pistachios) had a lower BMI and smaller waist circumference compared to non-consumers.

Your move: remove a less nutrient-dense food from your meal plan and incorporate heart-healthy nuts instead.

11. Schedule regular detoxes.
Why that's BS: "Your digestive system, kidneys, and liver are all actually fairly amazing at 'detoxing' your body on a regular basis," says Carroll. "There's no need for special cleanses or juices." (Plus, it's miserable! See what happens when one of our editors gave a detox a whirl.)

12. Eschew fatty egg yolks.
Why that's BS: Let's crack this case for good: A study from the University of Connecticut found that eating dietary cholesterol through egg yolks can actually boost a person's HDL, or "good," cholesterol. "Compared to egg whites, which offer nothing more than protein, the egg yolk contains 100% of the carotenoids, essential fatty acids, vitamins A, E, D, and K," says Batayneh. "They also contain choline, which boosts brain and liver health, as well as reduces inflammation."

In a way, eggs are the perfect food, says Kristin Kirkpatrick, MS, RD, manager of wellness nutrition services for the Cleveland Clinic Wellness Institute. "Enjoying them in moderation-less than 4 to 6 per week-is a perfectly healthy option."

13. Your burn more calories eating your food raw.
Why that's BS: "Many studies show that cooking method-heating, grilling, and microwaving, etc-makes a nutritional difference," says Kirkpatrick. "So while some food may be best eaten raw, that's not the case for all foods."

Oh, and if the whole myth about "negative calories" (you know, the dubious idea that just the act of eating certain foods burns more calories then you actually take in from those foods) draws you to raw foods, think again. "Some foods do require more energy to digest than others, but to live on these so called 'negative calorie foods' results in unsustainable weight loss and can also slow your metabolism down, as well as break down muscle," says Batayneh.

14. Too much sugary fruit makes you fat.
Why that's BS: The sugar in fruit is not what makes you fat, since it's unprocessed sugar found in its most natural state, says Psota. "Also, cutting fruit out of your diet is a poor choice because of all the fiber that you would be missing. Fiber keeps you full and the nutrients in the fruit nourish your body, which far outweighs the concern of natural sugar that you are consuming when eating, say, an apple."

15. Chew mint gum to eat less.
Why that's BS: Not to burst your bubble, but the lingering taste of mint can actually reduce the palatability of healthy food, finds researchers from the University of Buffalo. That means that when you spit the gum out and go for a snack, that candy bar's likely to look-and taste-a lot more appealing than a carrot.

More from Prevention: Check out these 25 Best Weight-Loss Tips Of All Time for painless ideas that really work.

By Stephanie Castillo, Prevention