Sure, most fads are silly to some extent, but fad diets are often next-level bonkers. And once you're a few years removed from these diets, they seem even stranger in the light of modern nutritional understanding. In fact, there are many ridiculous fad diets that should never come back and, hopefully, will stay in the past.

Of course, future generations will probably look back on today's eating habits and find plenty of things to ridicule. But it does not feel like many current eating plans are on the same level as these old-school fad diets. Many of these once popular diets focus on one food at the expense of most, if not all, others. But this leads to a boring and more or less impossible eating plan. I mean, if you are what you eat, why would you want to be cabbage soup?

Although these diets and their claims may sound fantastic, it's a good idea to remember that there is no easy fix that will change your body overnight. Basically, there's a good reason these diets did not become the mainstream food plans of choice. Look back at these silly fad diets and be thankful that you likely have much better nutritional options today.

1. Baby Food Diet


Have you ever been tempted by those little jars of baby food? According to WebMD, the baby food diet calls for grown-ass adults to replace regular meals with baby food. Strained peas, anyone?

2. The Cookie Diet


How could this possibly go wrong? As explained by U.S. News, people who follow the cookie diet eat special cookies all day and then a dinner of less than 700 calories. Does it sound too good to be true? Probably because it is.

3. Cabbage Soup Diet


Sure, veggie soups can be a great part of any nutrition-rich eating plan. As noted in WebMD, the bulk of this crash diet is made up of — you guessed it — cabbage soup. But as further explained by WebMD, this is not an easy diet for many people to stick with for that same reason.

4. Blood Type Diet


Sure, the premise may sound plausible. But according to Refinery 29, the idea of eating for your blood type has been debunked. Chances are, a healthy diet is right for every type.

5. Air Diet


The air diet, sometimes known as breatharianism, is pretty extreme. As noted in IBT, the air diet consists of ingesting only air, water, and a type of salt soup. It's a potentially dangerous diet, to say the least.

6. KE Diet


As noted in the Huffington Post, the K-E Diet (AKA Ketogenic Enteral Nutrition) basically uses a feeding tube. As the article further concluded, it may work for short-term weight loss, but it's not the best option for long-term changes. Also, there's a feeding tube involved. Not ideal.

7. Grapefruit Diet


Sure, fresh citrus fruit has its place in a healthy diet. But according to WebMD, the grapefruit diet will not necessarily melt fat. Also, grapefruit may interact or interfere with prescription drugs.

8. Fat-Free Diet


Does this give you flashbacks to the '90s? There's a reason it didn't work. As explained in WebMD, choosing a low-fat diet may contain added calories in the form of sugar or salt.

9. Alkaline Diet


Practitioners of the alkaline diet eschew foods that may cause your body to produce acid, such as meat, processed foods, and refined sugar, as explained in Shape. This isn't the worst idea in the world. But as the article further noted, there is no definitive evidence to back up the ideas that acid automatically equals bad.

10. 5:2 Diet


Eating what you want five days a week, while fasting for two, does not sounds like the worst plan for many people. And sure, many cultures have a tradition of intermittent fasting, but this does not mean the practice is right for everyone. According to the National Health Service, determining the safety and efficiency of the 5:2 diet will require more study, so you may want to think twice about it.

11. Cotton Ball Diet


This sounds like an urban legend. But according to Healthline, some people eat cotton balls dipped in juice in an effort to lose weight. As the site further noted, such behavior may be evidence of disordered eating, and it can even be fatal.