1. Paleo 

Let's start with the least of all evils, shall we? The paleo diet asks its participants to eat foods that can be gained through simple means of hunting and fishing. "Eating as the early humans ate" is supposed to be genetically better for the human body. While this may be great in theory, this does cut out common foods that could also make a case for sustainability today — mainly whole grains, legumes, and dairy products. This creates a more expensive diet for many, without the long-term studies to prove its worth.

Instead of fully going paleo, individuals can focus on a balanced diet with lots of fruits, veggies, and lean protein.

2. Juice detox 

Whoever thought you could take juice and pretend it was food was a little too optimistic, if you ask me. While there are a wide variety of juice detox methods, the main premise is that you only consume juice for a certain amount of time, normally 3-10 days. The desirable quality of this detox is that it literally flushes everything out of your body...the good, the bad, and the ugly. While that may be all fine and dandy, flushing the good out is where the issue lies — individuals on juice detoxes often lose too many nutrients, feeling weak and dehydrated.

Instead of taking on a liquid diet, add a cup of fresh juice to your breakfast. Get those benefits without passing out, OK?

3. The alkaline diet 

The alkaline diet is a lot of science surrounding the pH levels in your urine (you heard me). I'm convinced the people who participate in this diet have a lot of time on their hands and a lot of math in their brain. The diet splits up food groups based on the kind of metabolic breakdown it leaves — acidic, neutral, or alkaline. Alkaline is the desirable "ash" participants are looking for: fruits, nuts, legumes, and vegetables fit into this category. There's a lot of skepticism surrounding this diet, considering there's really no reliable evidence that checking your pee's pH level is making you healthier.

So don't go through the mind-boggling science to and uncomfortable pH checks — just eat more fruits and veggies and you'll be good to go.

4. The cabbage soup diet 

This is exactly what it sounds like — you eat fat-free, low-calorie cabbage soup for almost all your meals. It's split into seven days, each day allowing you to eat one or two different foods (some relief!) aside from your soup. You will, of course, lose weight in this calorie deficit, lose-weight-quick scheme, but it is recommended that you don't do it two weeks in a row and you are not to exercise while on your cabbage soup diet.

Here's the deal — you're more likely to stick with something if it tastes good. I don't make the rules, that's just how it works. Cabbage soup? It doesn't taste good, I don't care who you are. Taste preferences aside, any diet that doesn't want you to exercise because your blood sugars will be so low does not sound safe or healthy. Instead? Not to sound like a broken record, but eat plenty of fruits and veggies (that keep you energized and ready to exercise)!

5. The keto diet 

Keto, a diet I'm sure you're familiar with, focuses on low-carb and high-fat nutrition. By replacing almost all of your carb intake with fats, your body is put into a state of ketosis — in this state, your body becomes amazingly efficient at burning fat for the sake of energy. This means you lose weight. While on keto, some people experience a "keto flu" which could include poor energy and mental function, nausea, digestive discomfort, and increased hunger. Go ahead and add "crankiness" to that list, because it's just implied. It has also been widely recommended to not attempt keto for long amounts of time — low-carb diets can lead to vitamin or mineral deficiencies. Oh, and you will probably see shortages in your athletic performance.

Saying "low-carb, high-fat" leaves a lot of room for interpretation. If you're not eating bread, but you're eating a block of cream cheese, are you actually getting healthier? Understanding that good carbs (a lot of which can be found in whole grains and vegetables) are necessary to keep you moving and grooving during the day will have healthier, long-term impacts on your health.

6. Intermittent fasting 

Your friend who skips breakfast probably loves the idea of intermittent fasting. The diet revolves around the times you should and should not be eating — mostly limiting when you can eat to 8 hours during the day, asking you to fast for the other 16. For ideal intermittent fasting, you should also assign two non-consecutive days a week as "restricted" days, meaning you eat 500 calories or less. The problem with this is irritability, hunger, dehydration, and the possibility of triggering eating disorders for individuals who have that tendency. It's a lot of limitation that isn't totally necessary for weight loss or general health, so putting yourself through it may not be worth it.

Instead of skipping breakfast (arguably the most delicious meal of the day), just be more aware of your late-night snacking habits. Science does back up the notion that those late-night munchies do nothing good for your digestive system.

7. Whole 30 

Ah yes, the diet that seems like a great idea until you're making your own ketchup at 2 a.m. because Heinz has added sugar in theirs! Whole 30 is designed to change the way you eat within the course of 30 days while removing inflammatory foods (sugars, alcohol, grains, dairy, processed foods). This is great in concept and short-term experimentation to better understand your body, but Whole 30 is regarded by nutritionists unsustainable, restrictive, and too high in sodium and cholesterol — it was ranked LAST in the 2018 "U.S. News & World Report" annual diet list.

Instead of going cold turkey in the sugar department, understand that processed foods are never really your friend in the first place. Shop the outside of your grocery store, not the aisles filled with boxed treats. Focus on whole ingredients, no matter if you're making cookies or a salad!

8. The cotton ball diet 

You ready for some crazy talk right now? The cotton ball diet suggests dipping cotton balls in juice and eating them in order to curb your hunger and lowering your calorie intake. This emerged within the modeling industry, with women who felt the pressure to be thin at an unhealthy level. Now, the cotton ball diet is considered to be an eating disorder.

Eating cotton balls — or anything that's not actually food — has the ability to greatly harm your body. So stick to food, ok? If anyone says to dip any household product in juice and swallow it, don't give them the time of day!

SEE ALSO: That New Fad Diet You're About To Start In 2020 Won't Make You Healthier, Time To Rethink Your Resolution

9. SlimFast 

You know those little shakes that soccer moms used to swear by? They're SlimFast, and while they sound like they could easily be the cheesiest diet on this list, they're actually good in theory — but poor in execution. SlimFast allows its participants to eat six times a day (a win!), but only one of those six times is an actual meal (seemed too good to be true). Replacing two meals with a SlimFast shake, eating one normal meal, and having three 100-calorie snacks throughout the day is the name of the game, but it's far from perfect. SlimFast products have been found to be heavily processed, and while I can't speak for their taste, not many people like them.

Instead of sticking a bunch of chemically processed, overpriced "foods" into your body and hoping for results, eat five or six small meals a day, full of real food!

10. Food combining 

The general concept of food combining is something we do naturally, as human beings. Cheeseburger? Fries! Peanut butter? Jelly! This diet takes that notion a step further by designing food combinations that are supposedly "ideal" for your digestive system when eaten together. This brings a large list of dos and don'ts. For instance, don't eat protein with starchy food like grains. I'm sure you can see how this is already an adjustment, considering how most dinner plates are composed. There is also no scientific evidence to back up food combining as a successful diet. Alongside that fact, many foods are "mixed," meaning they could belong to more than one category. That's just confusing. And not sustainable.

Keep combining foods that are good for you! But don't give yourself a headache worrying about how they combine in your digestive system!

11. The 4-hour body diet 

The 4-hour body diet, while not as widely known, came out in 2010 and gained a loyal following fairly quickly. This program asks you to follow its strict instruction and stick to protein, legumes, and non-starchy veggies — it's a lot of repetition, so get excited. You do get one cheat day a week that you can specifically eat WHATEVER you want, in whatever quantity you desire. There is either a lot of limitation or dieters gone wild in this diet, neither of which are healthy, sustainable, or giving you the nutrients your dear ole body desires! Major cons are the limitations in food (creating a diet that many find hard to stick to), too much protein (you're supposed to keep protein intake at 10-35 percent of your daily intake), nutritional deficiencies, and incompatible for many medical conditions.

Instead of going all-in or all-out, like the 4-hour body diet asks, create balance in your life. Otherwise, you may end up tired and discouraged.

12. The raw food diet 

Another diet that is exactly what it sounds like — the raw food diet wants you to eat food that is unprocessed, and in large, uncooked. Those who swear by this diet believe that foods were intended to be consumed raw and that the body better fights disease when it is nourished in this way. Science has not confirmed this, so take that with a grain of salt (oh, you also can't have salt in this diet, FYI).

Even though the raw food diet is largely plant-based, participants are often still missing out on major nutrients. It's also been found that this diet negatively impacts bone mass, lowers HDL (good) cholesterol, and the participants could be at risk for cardiovascular problems.

The long and the short of it? It's ok to cook that carrot before you chow down!

13. The military diet 

Do you run from workout classes labeled "Bootcamp?" Then lace up those sneakers, you're not going to want to be anywhere near this way of eating. The military diet is a 3-day meal plan that is supposed to help you lose 10 pounds in one week. It's pretty rigid and bizarre. For instance, lunch on day one is a slice of toast, half a cup of tuna, and a cup of black coffee. Oh, that cup of black coffee is present for every meal...no wonder people are losing 10 pounds! Yet because of the abnormal eating habits, people are sure to gain that weight back once their 3-day plan is done. Nutritionists do not recommend repeating the meal plan often, especially within a couple of weeks of each other.

Instead of giving yourself 3-days to rid yourself of problems, focus on long-term, realistic habits (and less dinnertime coffee) that are good and sustainable for your body.