7 fad diets you shouldn’t try

Every day it seems a new diet is ready to make weight loss faster and easier than ever before. Or at least they say they are.

"Most fad diets go something like this: Take a few foods, give them 'magic' power, and set a plan to convince people that eating this way and only this way will promote weight loss," said Alexandra Caspero, RD, a nutritionist based in Sacramento, Calif.

The following diets might spur short-term weight loss, but many are difficult to follow, have arbitrary rules, and a few could put your health in danger.

The raw food diet
Any weight-loss expert would agree that boosting your veggie and fruit intake while reducing the amount of junk you eat is a safe and effective way to lose weight, but this diet bans foods that have been cooked or processed in any way. Why? Raw foodies say cooking destroys nutrients. Though it's true that cooking produce can sometimes reduce nutrient levels, cooked veggies still pack plenty of fiber, vitamins, and minerals, and in some instances cooking actually enhances nutrients while also killing bacteria. The biggest issue with this extreme form of veganism? Food prep—it's totally impractical, said Christopher N. Ochner, director of research development and administration at the Mount Sinai Adolescent Health Center. Raw foodies spend hours upon hours juicing, blending, dehydrating, sprouting, germinating, cutting, chopping, and rehydrating.

Health.com: 12 Things You Need to Know Before Going Vegan

Alkaline diets
The alkaline diet—also known as the alkaline ash diet and the alkaline acid diet—requires you cut out meat, dairy, sweets, caffeine, alcohol, artificial and processed foods, and consume more fresh fruits and veggies, nuts, and seeds. The diet certainly has positive points; it's heavy on fresh produce and other healthy, satisfying foods while eliminating processed fare, which in itself may spur weight loss. But your body is incredibly efficient at keeping your pH levels where they need to be, so cutting out these foods really won't affect your body's pH, Ochner said. Not to mention there's no research proving that pH affects your weight in the first place. The bottom line: the diet is strict, complicated, and bans foods that can have a place in a healthy eating plan, such as meat, dairy, and alcohol.

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The Blood-Type Diet
Developed by naturopathic physician Peter D'Adamo, the Blood Type Diet is based on the notion that the foods you eat react chemically with your blood type. For example, on the diet, those with type O blood are to eat lean meats, vegetables, and fruits, and avoid wheat and dairy. Meanwhile, type A dieters go vegetarian, and those with type B blood are supposed to avoid chicken, corn, wheat, tomatoes, peanuts, and sesame seeds. However, there's no scientific proof that your blood type affects weight loss. And depending on your blood type, the diet can be extremely restrictive.

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The werewolf diet
Also called the lunar diet, this one is simply fasting according to the lunar calendar. Its quick-fix version involves a day of fasting allowing only water and juice during a full or new moon—and supposedly losing up to six pounds in water weight in a single day. The extended version starts with that daylong fast and continues with specific eating plans for each phase of the moon. While you'll lose some weight from not eating, it has nothing to do with the moon, and it will come right back, Ochner said.

Cookie diets
Dr. Siegal's Cookie Diet, The Hollywood Cookie Diet, and the Smart for Life Cookie Diet all promise that eating cookies will help you drop pounds. Of course, you don't get to chow down chocolate-chip cookies—you eat about 500 to 600 calories a day from high-protein and high-fiber weight-loss cookies (one cookie company even makes the cookies from egg and milk protein) for breakfast, lunch, and any snacks. Then you eat a normal dinner, for a total of 1,000 to 1,200 calories a day. If you stick to the diet, you will likely lose some weight, but by depriving yourself all day, you set yourself up for bingeing come dinnertime, Ochner said.

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The Five-Bite Diet
Eat whatever you want—but only five bites of it. On this diet, developed by obesity doctor Alwin Lewis, MD, you skip breakfast and eat only five bites of food for lunch and five more for dinner.

"I'm OK with the idea of eating whatever you want in smaller portions, but you need to round out the rest of your eating with nutrient-dense foods to give your body the fuel it needs," Caspero said. "On this diet, even if you take giant bites of heavily caloric food, you're still barely consuming 900 to 1,000 calories a day."

The HCG diet
This edge-of-starvation diet limits you to about 500 calories a day while taking human chorionic gonadotropin (HCG), a hormone that proponents tout as a powerful appetite suppressant. However, there's no evidence that HCG does more than act as a placebo, Ochner said. Yes, you'll lose weight, but only due to the extreme calorie restriction. Though a health care provider may legally give you HCG injections, they're typically used to treat fertility issues in women and the FDA has not approved them for weight loss. As for over-the-counter homeopathic products that supposedly contain HCG? Those are illegal.

14 Fad Diets You Shouldn’t Try originally appeared on Health.com.