Chances are, you or someone you know has tried a fad diet. Fad diets are the opposite of science-based nutrition advice, and they often consist of arbitrary (and sometimes hilarious) rules that apply to everyone. Their appeal lies in the pitch: eat exactly this and you'll magically lose weight, even though we know deep-down that losing weight is a combination of time and consistent effort. And here at Habit, we know that diets are not one-size-fits-all.Rumor has it that going lectin-free will be the next fad to make waves, and this got us thinking, how did we get here? We went back in time and gathered seven of the most noteworthy fad diets—many are funny, a few seemed reasonably legitimate in their heyday, and some are downright scary.

1. The Cigarette Diet

In the 1920s, cigarette companies found a new marketing angle: light up a smoke and you won’t feel like eating anymore. Lucky Strike even launched a campaign called “Reach for a Lucky Instead of a Sweet,” which went on to be a huge success. Fortunately for lungs everywhere, people eventually figured out it was just a phony advertising scheme. (Don't worry Don Draper, you can always come work for Habit.) [Photo Credit: Stanford University]

2. The Sleeping Beauty Diet

Disney jokes aside, this is probably the most relaxing fad diet. This diet argues that lack of sleep is a major contributor to weight gain. The solution? Sleep away the pounds. Interestingly, there may be some truth to this—lack of sleep has been linked to higher weight and higher levels of the “hunger hormone” ghrelin. It’s worth noting that if this diet does help you lose weight, there’s a good chance it’s because it’s hard to eat while you snooze.

3. The Master Cleanse

Also known as the Lemonade Diet, this fad involves swearing off solid food in favor of a beverage made of cayenne pepper, lemon juice, maple syrup, and water. The diet was built around the claimed benefits of capsaicin, an active component in cayenne pepper. It’s been suggested that capsaicin has magical fat-burning properties, but scientists are skeptical that cayenne pepper can actually help someone lose weight.

You begin the Master Cleanse with a laxative salt-water flush, then spend the rest of your day drinking 6 to 12 glasses of the cayenne-lemon-maple water. After a week, the pounds will melt off. The only problem: the pounds will likely come back once you start eating solids again.

4. The Baby Food Diet

This diet instructs people to eat several jars of baby food for breakfast and lunch, followed by a grown-up-friendly meal for dinner. You’ll probably lose weight in the short-term since you are cutting calories. The downside is that you’re missing out on protein and other nutrients your body needs. On the bright side, you won’t have to worry about your coworkers taking your lunch from the office fridge.

5. The Cabbage Soup Diet

On this seven-day plan, you can eat as much cabbage soup as you want. You can also eat a few other foods, although the logic behind the instructions can seem a little random. For example, on day two you’re instructed to eat a baked potato with butter for dinner. On day three, don’t even think about touching a baked potato. To be fair, even the creators of the diet agree that it doesn’t lead to long-term weight loss.

6. The Cotton Ball Diet

This is a real fad diet that involves eating cotton balls (either plain or dipped in orange juice) instead of eating food. While cotton balls are technically low in calories, there are two main downsides to eating them: they’re usually made of synthetic fibers and chemicals, and they could cause a super dangerous obstruction in your GI tract.

7. The Tapeworm Diet

This diet isn’t for the squeamish. It involves eating tapeworm eggs, allowing them to hatch inside your GI tract, and then letting the tapeworms consume the food you swallow. It’s hard to believe that anyone would actually follow this diet, but several cases have been reported (and likely involved a few hospital visits).