Quiz: Can You Spot a Dangerous Diet?

False. Starving yourself or going without food to lose weight fast is a bad idea. It actually slows down your metabolism (or how well your body burns calories). Your body tries to store as much food as it can. So even if you do lose weight, you can gain it back that much faster, once you do start eating again.

You need a steady stream of calories, every day, to have energy and keep growing. For most, that means eating at least 1,800-2,200 calories a day and more if you’re super active. To keep your metabolism fired up:

1. Always eat breakfast.
2. Watch your portions. Try having three small meals and two small snacks over the course of your day.

False. Carbohydrates have gotten a bad rap, but all carbs are not created equal. Processed or refined carbs, such as white bread, white pasta, or white rice, are the bad guy here. Why? During processing, lots of good vitamins, minerals, and fiber are stripped from the outside of rice, wheat, or other grains.You don’t get the nutritious bang for your buck or stay as full as you would by eating whole, natural foods.

Instead of banning all carbs, put vegetables, whole grains (like brown rice or whole wheat bread), or fruits on your plate -- these are carbs, too, the healthy kind.

When you cut carbs too much -- like some people do on the Atkins diet or Dukan diet -- you can get some pretty gross side effects. Like:

• Bad breath
• Bloating
• Constipation

False. Heard of lemonade spiked with cayenne pepper and maple syrup? Turns out most cleanses don't do much for you. Your liver and kidneys naturally cleanse your body of toxins. But cleansing diets can make you dizzy, headachy, nauseated, and weak because many won’t give your body enough calories for energy. When cleanses also include laxatives, they can leave you dangerously dehydrated.

Want your body to feel "cleaner"? Skip sodas and sugary sports drinks and even juice. Drink several glasses of water a day to help your body flush toxins naturally and keep your skin glowing. You’ll know you’re getting enough H20 when your pee looks almost clear.

False. Fat isn’t your enemy. You actually need some fats. Unsaturated fats -- like those that come from plants like avocado and nuts -- are best. They are a healthier choice than saturated fats in chips, mayo, or cheese dip. Try a handful of nuts the size of a golf ball for a healthy snack. Or add four thin slices of avocado to your next sandwich instead of mayo. Ask for guacamole instead of queso or cheese dip.

Good fats make for healthy skin, hair, and nails. They also leave you feeling satisfied. 

Plus, some processed foods advertised as fat-free are really junk food disguised as healthy. They can be loaded with sugar (to make up for a lack of flavor) and can be full of empty calories without many good nutrients.

D. All of the above. Diet pills claim to work by raising your metabolism (how your body burns food). But some diet pills can dangerously amp up everything else inside you, too. Some diet pills can:

• Make you sweat a lot
• Make you nauseous
• Keep you up at night
• Speed up your heartbeat -- some have been linked to heart attacks

It’s best to stay away from them altogether. Although taking a little magic pill can’t help you get to or stay at a healthy weight, you can start by making small changes one at a time.

If you drink sugary drinks like sports drinks and even juice, try cutting back over time. This week, work on having just one sweet drink a day. Then have just one every other day and keep cutting back from there. You get the idea. Or, try walking around the block after dinner. Keep it up and you’ll get real results that will last!

False. Just because something is herbal or "natural" doesn’t make it gentle -- or safe. Too much of "natural" ingredients -- like caffeine, ginseng, and green tea -- in herbal weight loss supplements can be bad for your heart, just like diet pills.

What's more, supplement pills aren't regulated by the Food and Drug Administration. That’s the branch of the government responsible for making sure what we eat, drink, or medicines we take are safe and work. Because supplements aren’t regulated, you can never be sure what they are made out of or believe their claims.

True.  You're probably not surprised. The guy who “created” the Twinkie diet, mostly as a joke, wanted to prove that you lose weight when you cut calories -- no matter what food you eat.

The problem is that processed junk food like Twinkies -- and even some 100-calorie snack packs that are advertised as "healthy" -- are not filling. And they don't give your body many nutrients that it needs for energy and to stay healthy.

If you're worried about losing weight, talk with your doctor. She can figure out if you are at an unhealthy weight. And if it would help to lose some weight, she can help you do it the smart way -- making sure you’re getting a balanced diet, and not just empty calories.

False. A big red flag for any weight loss plan is if you can only eat one food or only eat from of a limited list of foods.

Sure, you get Vitamin C from grapefruit and fiber from cabbage -- but you won’t be getting enough of anything else. And, really, how many times can you stare down another grapefruit or bowl of cabbage soup?

Instead: Mix up the fruits and veggies you put on your plate. Challenge yourself to find some new favorites. And aim to fill half your plate with vegetables and fruits at every meal.

False.  Going vegetarian can be a healthy choice, but you need to be smart about how you do it. Why? Eating meat is an easy way to avoid anemia -- that's when you have low iron and it makes you feel tired. And it's easiest to get protein for healthy muscles by eating fish, meat, eggs, or low-fat dairy. And you still need calcium and vitamin D for your bones. It's easiest to get those from dairy foods like low-fat milk, low-fat yogurt, and low-fat cheese. But you have options.

If you're skipping meat, eat dark-green leafy vegetables, iron-fortified breads, or cereals to get iron and help avoid anemia. For protein when you're skipping meat and dairy, try tofu or other beans.

Dairy can be tougher to replace. Greens and some veggies have calcium but you may have to eat a lot more than you think to get enough calcium and vitamin D. Some orange juices have Vitamin D so that can help. But remember, juice can have a lot of unhealthy sugar. Try sticking to just one 8-ounce glass a day.

Bottom line: If you're giving up meat or dairy, talk with your doctor about how to do it safely and whether you should take vitamins.