Many teenagers and young adults care greatly about their body image and dieting habits, which is probably why there are so many diets out there trying to find the absolute best way to eat and drink.

“Any diet that totally restricts particular kinds of food, generally, can cause some really serious health concerns, and it’s really difficult to maintain long-term, so people usually do it, lose weight, the return to their old eating habits. I would say the focus of most diets is immediate weight loss instead of long-term, maintainable changes,” said Amador health teacher, Diane Farthing.

Farthing warns against subscribing to any diet that promises to get rid of weight quick. In fact, the only diet she recommends is weight watchers, since it monitors and keeps track of the varied food you eat.

Many diets out there are “crash diets.” In which the person goes on the diet to achieve results as fast as possible.

Just take a quick look at most diet pages, most of them give promises of getting rid of weight quick. However, health experts warn against “yo-yoing” between different diets such as detox cleanses.

“They go on fasts, yo-yo diets, detox programs, and ‘cleanses’ without realizing that there are serious consequences to weight loss and nutrient restriction,” said Bacon, a nutrition professor at the City College of San Francisco, California, and the author of Health at Every Size: The Surprising Truth About Your Weight.

These are especially dangerous with fad diets, diets that are mostly spread quickly on social media, used by a few people, and then are never heard of again.

Some fad diets are especially strange, such as the banana diet from Japan that came to the US, which states you should be eating multiple bananas for breakfast, with no changes to your diet otherwise.

Some are explicitly concerning, such as the tongue patch diet that makes it painful to eat when it’s on your tongue, so you only eat when absolutely necessary, or the KE diet that gives you a small, surgically-inserted feeding tube to keep you from eating yourself. Even in the early 1900s, con artists gave pills containing tapeworms, something they claimed would help the user lose weight.

Many of these diets are likely made by people who are desperate to lose weight because they keep gaining it back after every diet they try. Sandra Aamodt, a neuroscientist, explained in her Ted talk that the brain tries to keep the body in a certain range of weight called the set point. It’s hard to lower the set point, but really easy to raise it.

Both Aamodt and Farthing claim that the best way to stay healthy is to eat a variety of foods, staying away from most cleanses that promise quick results rather than long-term changes in habits.