25 Trendy Fad Diets That Are Total BS

If you're one of the one percent that suffers from celiac disease, according to The Celiac Disease Foundation, or have a gluten intolerance, you're eating this way to preserve your health, and you should continue to do so. But if you're nixing carbs because you want those celeb-worthy abs? Consider it a no-go, as there's no research to support going g-free for weight loss. Of course, ditching high-calorie processed eats like muffins, cakes, and snack foods can get rid of unwanted pounds (assuming you don't fall into the common trap of digging into more processed eats, thinking they're healthy because they say "gluten-free" on the label)—but it's not because you're not eating gluten, but rather because you're cutting junk calories.

Meal replacement sips, like Plexus Slim and Shakeology, have their loyal followers, and we won't deny people have seen success with them. In the short-term, this may be a fine strategy to help break the fast food/vending machine lunch habit (many say the products are actually crave-worthy delicious, so that helps). However, while limited research suggests that they can help you lose weight, there's one big downside: replacement shakes don't teach you a life-long way of healthy eating. So if you need a jump start, we won't slap you on the wrist...but start educating yourself about healthy fare you can cook and order out, and opt for a diet that suits your lifestyle.

Here's the gist: for one week you eat a couple bowls of cabbage soup a day, plus a prescribed set of foods. For example, one day you might eat only cabbage soup plus bananas and skim milk. Another might be cabbage soup and beef and veggies. Sounds fun, right? "Cabbage soup is a wonderful soup, but as a diet it's bogus," says Bonnie Taub-Dix, owner of Betterthandieting.com and author of Read It Before You Eat It. It's rigid, unbalanced, and again, only a short-term solution for weight loss.

Should you do what Megan Fox does and take a shot of vinegar? We're torn. While some research shows that vinegar can help improve blood sugar—especially if you have type 2 diabetes—there isn't convincing research that shows it can actually help you lose weight. Drizzling it onto your salad for a boost of low-cal flavor? A good idea. But save yourself the gagging after knocking back the shot. ACV won't work miracles.

Experts have long said that the best way to get nutrients is from food. And that's where diets that require you to take supplements, like the Hallelujah Diet, falter. They start off on a good foot, touting the benefits of eating more produce, but then recommend a plethora of supplements to fix nutrient deficiencies and detox your body. But getting on a plant-based diet alone will help you lose weight—you don't need to pop pricey supplements to get you there.

Shocker! While going on a low-fat diet is better than doing nothing at all to drop unwanted pounds, it's not the best weight loss strategy (aka, you're wasting your time). In a new meta-analysis of nearly 70,000 dieters, in the long run, people lost less weight on low-fat diets compared to higher fat diets. Now, that doesn't mean ice cream melts love handles—keep it to sensible portions of healthy fats like avocado, olive oil, and nuts.

If you've got a sluggish thyroid, you're at risk for fatigue, depression, and constipation. Unfortunately, there's no cure—and the only thing that's been shown to regulate your thyroid is medication. Some people suggest you eat more iodine-rich foods, like seaweed and cranberries, but it hasn't been shown to cure hypothyroidism, according to the Mayo Clinic. The good news is that meds can help keep symptoms at bay in most cases, so talk to your doc about which ones are best for you.

Give up gluten, dairy, alcohol, fatty meats, caffeine, sugar, and processed foods—sounds a lot like Tom Brady and Gisele Bundchen's diet. Of course you're going to lose weight, but we imagine you'll have no fun doing it. It's very restrictive, but true elimination diets are supposed to be temporary and designed with a medical purpose: to detect a suspected food allergy. Skin and blood tests are also needed for a diagnosis, and the Food Allergy Research & Education organization suggests only doing this with your doctor. Bottom line: it's not a fit-into-your-skinny-jeans diet.

If Kelly Ripa says it changed her life, you've got our interest (have you seen her abs?). Followers say that foods can alter the pH of your blood and urine, which can affect everything from weight gain to cancer risk. You'd avoid acid-producers like wheat, dairy, meat, sugar, and processed food, and nosh on more alkaline ones (aka foods that reduce the acid levels in your body) like fruits and veggies, nuts, and tofu. The problem? There's no evidence to show that foods can even change your body's pH, according to the American Institute of Cancer Research, making the diet moot. One upshot: these are all healthy foods. Eating more produce and less processed stuff can help you lose, but it's got nothing to do with pH.

Avoid, avoid, avoid. The FDA calls this diet a reckless way to shed pounds and deems it potentially dangerous. HCG (human chorionic gonadotropin) is a hormone that your body makes during pregnancy, and on this diet you're supposed to eat 500 calories a day, then use HCG (lotions, drops, etc) to increase levels of the hormone in your body. Proponents of the diet say it's supposed to decrease hunger from, um, eating basically nothing all day. But the FDA says these products are illegal, not approved for weight loss, and there's no evidence HCG even works for weight loss. Translation: just say no.

If you're getting a colonoscopy and need to prep for the procedure with a liquid diet, then more power to you. But if you're drinking only liquids to get thin, it's time to rethink your strategy. "Most juices and liquids lack protein. You can't live on that," says Taub-Dix. Plus, chewing tends to make people feel satisfied, so count on feeling hungry. Sounds like a recipe for disaster.

When you're going to marry the future king of England, do as Kate Middleton reportedly did and follow the Dukan Diet. The high-protein plan makes big promises, including losing 10 pounds the first week, but the U.S. News & World Report notes that there are a lot of rules (like what vegetables you can eat and when) that make it hard to follow. Basically, there's no evidence that you can stay on it long-term, and if you're going to go through the trouble to lose weight, don't you want to keep it off?

Cold water makes your body work hard to bring it down to room temp, thereby burning extra calories. The resulting metabolism boost means that you're supposed to drink ice water before meals. "There's a bit of truth to the idea that cold water could change your metabolism slightly—but not enough to make a huge difference," says Taub-Dix. And research shows it's largely a myth that drinking more water can help you lose weight. Sip H20 because it has no calories—not to burn them.

We can't verify the origins of this diet, but it reeks of bunk. Here's why: the premise of this seven-day-diet is that you fill up on a low-cal vegetable soup, plus a variety of prescribed foods on different days (think skim milk on one day, beef the next, a potato after that…). Aside from being crazy difficult to follow and making absolutely no sense (why do you need to eat three bananas on day three?), there's no evidence to say you should try it. Besides, what happens after the week is up?

Once the staple way of eating for Gwyneth Paltrow (before she launched her cookbooks), this just-about-vegetarian diet nixes meat, dairy, eggs, processed foods, and added sugar. What's allowed? Piles of whole grains, veggies, legumes, and soy (fruit, fish, and nuts are "occasional" foods). One supposed benefit is warding off diseases, like cancer, but the jury is still out. Healthy? Yes. Will you lose weight? Probably. Too restrictive? Double yes. While it's not a crash diet, this one's hard to follow in real life and offers no wiggle room for the occasional treat.

Another lower-carb plan where you can lose weight without calorie counting, the South Beach Diet has you load up on protein, good fats, and low-glycemic carbs, which keep blood sugar steady—essential in fighting off crazy cravings (fro-yo, we're looking at you). The kicker: advocates promise that you can lose up to 13 pounds in the first week. But don't get too excited yet: there's not much research on SBD long-term results, and in one study people didn't lose any more weight than a control group. Since, hello, long-term weight loss is what you want, we're gonna say give it a hard pass.

Also known as the Lemonade Diet. If you need to see how effective it can be, look up Beyonce—it's the diet she reportedly used to lose 20 pounds for Dreamgirls. You'll drink a concoction of water, lemon juice, cayenne, and maple syrup throughout the day, plus consume a saltwater flush. "This has been around for decades and it pops up every year around New Year's," says Pamela Salzman, an LA-based cooking instructor and holistic health counselor. The problem is, "I see a lot of people overeating around the holidays thinking a cleanse will offset this crazy bingeing they're doing. It's not a healthful attitude," she says. Not to mention this plan is difficult to follow if you need energy to do, well, anything. With so few calories and a lack of nutrients, you won't be able to feed your body and brain what it needs to function. Sure, it may work in the short term, but you'll gain everything back once you start eating again.

Should you go heavy on protein? Vegetarian? It's all about your blood type, according to this diet. Created by naturopathic physician Peter D'Adamo, he says your blood type clues you in on how your body reacts to food, helping you lose weight and fend off disease. Unfortunately, there's no evidence to back up the premise, so stick with what we know works until smarty-pants scientists tell us otherwise.

An oldie but goodie: this diet from the '70s is a two-week low-carb, low-cal diet. In fact, you're expected to eat just 700 to 1000 calories a day, all on a rigid schedule. For example, breakfast is half a grapefruit, a piece of toast, and coffee. You'll certainly drop pounds, but may go crazy in the process (come on, how much grapefruit can you really eat?). We probably don't have to tell you that this deprivation-loving diet that requires you to muster up a ton of willpower has no studies backing it up. But if you want to lose weight quickly and don't care about gaining it back...wait, no, just don't do it.

If you can believe this, the story goes that General Motors developed this diet for their workers to lose weight. (However, GM has since denied it to The New York Times, calling it an urban myth). It's a week-long plan designed to help you lose at least 10 pounds eating a prescribed set of foods. (Think: eating only fruit for a day. Then eating only vegetables for a day.) Surprise! There's zero evidence to show the crash diet helps with anything but short-term weight loss. Heck, even GM won't take credit for the idea, so what does that tell you?