5 Of The Worst Diets Ever

For every eating plan based on fundamental nutrition principles, like the DASH diet, there are numerous “fad diets” out there.  Many involve severely restricting caloric intake, eating at strange times of the day, or loading up on a supposed miracle food.  The main reason so many people try various fad diets is that many dieters want immediate results, and it’s tempting to fall under the spell of the unbelievable before and after photos. 

Fortunately, nutritional experts like registered dietitians can provide irrefutable evidence that almost all fad diets don’t work.  Instead, you should follow a diet backed by scientific research such as the:

  • Mediterranean diet
  • DASH diet
  • MIND diet
  • Flexitarian diet

Unlike the diets listed above, the following 5 fad diets are some of the worst dietitians have seen over the last 25 years. 


Master Cleanse Diet

The Master Cleanse (aka The Lemonade Diet), is a modified juice fast that’s used by some people for rapid weight loss.  The basic components of the cleanse are simple:

  1. Squeeze fresh lemon juice into water, maple syrup, cayenne pepper, and water
  2. Drink 6-12 glasses throughout the day
  3. Take a laxative before bed

Most people following this diet adhere to the all-liquid cleanse for ~10 days to “de-toxify” their digestive system. 

Why it doesn’t work

Yes, if you follow the Master Cleanse you probably will lose weight temporarily.  However, most of it will be water weight that you’ll quickly gain back once you start eating solid food again.  Plus, your metabolism will slow down which can cause even further weight gain once you stop the plan.  Finally, by doing this cleanse you’re basically inflicting temporary malnutrition on yourself – your body is getting no food with any significant nutrient value.  That can lead to nausea, weakness, or possible hospitalization. 


A sample meal from The Military Diet Plan.

A sample meal from The Military Diet Plan.

The Military Diet

This diet was supposedly invented to get overweight recruits into shape quickly.  However, the US military says that couldn’t be further from the truth and they’ve never used the diet.

The military diet must be followed using a 3 days on, 4 days off pattern.  This means you’ll follow the diet for 3 days and cut your caloric intake, then eat normally for the next 4.  While you’re following the diet, meals tend to be small and unvaried.  An example Military Diet meal is:

  • 3 oz of meat
  • 1 cup of green beans
  • ½ banana
  • 1 small apple
  • 1 cup of vanilla ice cream

Why it doesn’t work

The 3 days on, 4 days off approach is a risky cycle that could lead to a habit of binge eating.  The diet also requires certain high saturated fat, high-sodium foods like hot dogs and ice cream that aren’t good for you.  


Blood Type Diet

The basis of this diet is that what you eat should correspond to your blood type.  Naturopath Peter D’Adamo created the diet, on the claim that foods you eat chemically react with your blood type, and you’ll digest foods more efficiently if the two are in sync.  For example, type A people should eat vegetarian while type O has to stick with meats and fresh produce.  The diet dictates that you eat very specific foods, so it doesn’t allow for many personal preferences. 

Why it doesn’t work

First off, there’s no scientific research backing up the merits of the blood type diet.  There are also many complex rules and you’ll have to cut out many healthy, commonplace ingredients.


While eating lots of fruits and veggies is healthy for everyone, the Raw Food Diet is too restrictive for most people. 

While eating lots of fruits and veggies is healthy for everyone, the Raw Food Diet is too restrictive for most people. 

Raw Food Diet

A raw food diet entails eating mostly uncooked, unprocessed foods so you get nutrients without harmful additives.  The diet is made up of mostly fruits and vegetables, and incorporating lots of those is good for everyone.   Many people who follow this diet are also vegan, meaning they don’t eat any animal products for health or environmental reasons.

Different than some of the other diets listed in this article, the raw food diet is more of a lifestyle choice than an easy weight loss attempt.

Why it doesn’t work

One of the main problems with a raw food diet is that it’s really tough to get enough calories because of how restrictive the diet is – you basically can’t eat anything but fruits and veggies.  Plus, you can’t eat many healthy foods like lean meats (unless they're raw), legumes, and other cooked grains.


The Low-Fat Diet

In the past, especially the 90’s, a low-fat diet was very trendy.  The basic premise is to choose foods low in fat because if you eat high-fat foods your body fat percentage will increase. 

Why it doesn’t work

Not all fats are bad, in fact many fats are very good for you.  You should limit intake of saturated and trans fats, but mono and polyunsaturated fats are healthy and make up a significant portion of the Mediterranean diet (rated one of the top diets by US News and World Report).  Eating healthy fats like avocados, almonds, and salmon also help you absorb fat-soluble nutrients from other foods.