Mono Diet: How Does it Work?

The mono diet is one of the most popular diets in recent years. If you have heard about this diet, then you most likely know it claims that it could result in quick weight loss. However, there is no evidence to support these claims.

The mono diet started becoming more popular in 2016, after the book “Presto! How I Made Over 100 Pounds Disappear and Other Magical Tales” was published by Penn Jillette. In the book, the author credits the 2-week mono-diet with starting his journey to lose weight. The primary idea was to disrupt his eating patterns with the mono-diet and then establish a healthy diet.

However, some might claim that this book is more of a comedy than a reliable resource. In some interviews, Penn even mentions that you do not need all nutrients within two weeks, which isn’t true.[i]

For two weeks, Penn claimed he only ate potatoes for the first five days. He then started eating some whole grains, vegetables, and fruits. People following the mono diet only eat one kind of food (such as potatoes or bananas) as they try to lose weight.

What You Can Eat

As mentioned above, people following the mono diet only eat one type of food for a certain period. Keep in mind that there are different variants of the mono diet, such as the chocolate mono-diet, the potato mono-diet, the egg mono-diet, and the banana mono diet. However, there are no formal or official rules for how you can follow this diet. As a result, it’s all open to different interpretation.

Some people follow the mono diet by sticking with a specific group of foods like meats, vegetables, or fruit. Other people eat the mono meals, consuming a single food for every meal but ultimately rotating the single food with different kinds of food. Regardless of what you choose to do, planning meals is very simple because mono diets require eating only one food or just a few foods.

The good news is that nearly all types of foods might be included on a mono diet. Some of the foods included in the mono diet include grapefruit, chocolate, watermelon, pears, bananas, milk, eggs, apples, and potatoes.

Keep in mind that there are some types of the mono diet that involves eating only one food group. Some types of food that can be consumed by people following the mono diet include legumes, vegetables, fruits, and meats.

If you’re new to the mono diet lifestyle, you don’t have to feel intimidated by eating only one type of food for a few days. The most important thing is to make sure you have enough stock for the kind of food you want to include in your diet.

Take It Slow

If you aren’t sure whether you’re ready to commit to the diet fully, you should take small steps to consume fewer animal products and meat. Consider taking one type of food in a day and see how it goes.

Make Healthier Swaps

You can still choose to consume different kinds of your favorite meals when following the mono diet. The most important thing you can do is making smart swaps. Love bacon; just grill your favorite meat and top it with a few pork toppings. Also, you can enjoy bananas with colorful veggies and whole-wheat crust instead of cheese or meat.

Learn To Eat Legumes

Beans should be your friends on the mono diet. Legumes offer fiber and protein that gives you a sense of satiety and fullness that you might have enjoyed when you consumed meat. You should stock up on dried or canned beans.

What You Cannot Eat

As mentioned above, almost any food might be consumed on a mono-diet, including bananas, eggs, apples, and potatoes. A few variations might involve choosing one type of food group and stick to it like legumes, vegetables, fruits, and meats.

What to Eat?

  • Potatoes – sweet potatoes
  • Bananas
  • Eggs
  • Vegetables and fruits (grapefruit, watermelon, apples), legumes
  • Chocolate

What to Avoid?

  • Nothing is prohibited

Does It Aid Weight Loss?

For many people, eating only one type of food every day will eventually result in reduced intake and lead to weight loss. For example, if you choose to only eat low-calorie foods such as vegetables, it’s highly likely you’ll eat fewer calories or no calories, which will ultimately result in weight loss.

However, if you eat foods high in calories, such as chocolate, you might quickly gain weight.[ii] One of the best things about this mono-diet is that it typically results in significant weight loss pretty fast because of the reduced calorie intake. Also, some people believe that severe restriction of calories can reduce your cravings for fat, salt, and processed sugar.

If you don’t provide the body with enough protein, you will lose muscle tissue, and this slows down metabolism.[iii] This means the body will start burning fewer calories and could put you at increased risk of adverse effects after you stop following the diet.

Consuming just one type of food like you should do when following the mono-diet and the non-protein containing food or low protein food will lose the muscle tissue, and if you start eating normally, you might quickly gain weight because of slowed metabolism. Remember, there is no sufficient research on if the mono diet is an effective weight loss regime.

The Rules Of The Mono-Diet

Different types of the mono diet are based on one rule; you only get to consume one type of food. However, you can eat as much food as you wish. The mono diet does not involve counting calories. This brings the question of how the mono diet aids weight loss. Essentially, there are no strict regulations or rules for following the mono-diet, which is the main reason people interpret the rules differently.

Many dieticians don’t recommend the mono-diet, mainly for health reasons. This is because many dieticians vouch for healthy ways of losing weight. Most advocates of mono diets believe that these diets cleanses the body, kill unwanted cravings and help people lose weight.

The simplicity of the mono diet is another important thing most people like about this diet. No counting calories, purchasing expensive exotic ingredients, no extensive shopping lists, or choosing what to eat in every meal since there are no strict rules.

Possible Health Benefits


Simplicity is one of the main benefits of the mono diet. Unlike other fad diets, the mono diet doesn’t have any complex guidelines for people to follow. Nevertheless, this is because the mono diets are very restricted and cut out many healthy foods. Also, it doesn’t require followers to measure portion sizes, count calories, or track nutrients, which might be very attractive to some.

Short-Term Weight Loss

The mono diet might be great for short-term weight loss, based on the types of food you eat and what portions. Also, keep in mind that this doesn’t have anything to do with this mono diet.

When following the mono diet, the weight loss is mainly because of calorie restrictions, which come from cutting back on many foods.[iv] An extreme diet plan will most likely result in short-term weight loss. Nevertheless, such diet plans aren’t sustainable in the long run.

While it’s not sustainable and it might be hard to follow for extended periods, some followers use it to start their weight loss journey before they transition to other diet plans. Overall, the mono diet is pretty simple and does not have any complex regulations or rules. It might also increase weight loss in the short term, based on what you choose to eat.

Sample Shopping List

People following the mono diet might want to do their shopping at the farmer’s market for seasonal and fresh produce. However, if there is a farmers market in the area where you live, look for local and organic vegetables and fruits at your grocery store. However, if you aren’t sure what is in season or buying organic isn’t within your budget, pick the produce that looks fresh.

The shopping list below offers great suggestions for getting started with the mono diet. Keep in mind that this isn’t a definitive list, and you might find other foods that are perfect for you.

  • Eggs
  • Potatoes, sweet potatoes
  • Fruits (grapefruit, watermelon, pears, bananas, apples)
  • Chocolate
  • Legumes and beans (sunflower seeds, almonds, walnuts)
  • Dairy (yogurt, cheese, reduced-fat milk)
  • Lean meats (turkey breast, fish, and chicken breast)
  • Whole Grains (oats, brown rice, amaranth, barley, quinoa)
  • Tempeh and tofu
  • Nondairy milk (soy, almond, oat)
  • Canned and dried legumes (chickpeas, lentils, black beans)
  • Tahini
  • Vegetables (carrots, eggplant, bell peppers, sweet potatoes, Brussels sprouts, cauliflower, broccoli)
  • Dark, leafy greens and vegetables (green beans, Swiss chard, broccoli, spinach, kale)
  • Organic lean protein (trimmed pork loin, chicken, halibut, salmon)

Sample Meal Plan

There are different kinds of mono diets, and there are multiple ways to follow the eating plan. The most common variation involves eating one type of food for every meal, such as eggs, apples, or potatoes. Other mono diet plans involve sticking to ingredients in a specific food group, like vegetables, fruits, or meat.

Also, you can choose to switch between different mono meals by consuming other food items in each meal. While there are no strict policies for how long you need to follow this diet, many use the mono diet to boost weight loss by following this diet for only one or two weeks.

Other types of foods can be reintroduced gradually, such as smoothies, salads, and soups, before you transition into a balanced and healthy diet. Following are the most popular mono diets out there. We’ve also discussed the sample meal plan for each mono diet.

Sweet Potato Mono-Diet

This diet involves the consumption of sweet potatoes. With this diet, you stick to taking sweet potatoes every day for the next two weeks. You don’t take any other food.

Day 1 – day 14

  • Breakfast – sweet potatoes
  • Lunch – sweet potatoes
  • Dinner – sweet potatoes

Potato Mono-Diet

The potato mono-diet is another popular mono-diet, which many people have adopted. With this diet, you’re only required to eat potatoes every day for the next five days. You should consume between 2 and 5 pounds of potatoes each day. You shouldn’t take any other food, including condiments and toppings like ranch, cheese, tomato sauce, and more.

Day 1 – day 5

  • Breakfast – potatoes
  • Lunch – potatoes
  • Dinner – potatoes

Banana Mono-Diet

The banana mono-diet advocates for the consumption of bananas for the next 12 days. Keep in mind that you don’t eat anything else besides bananas, but you can eat as many bananas as you want.

Day 1 – day 12

  • Breakfast – bananas
  • Lunch – bananas
  • Dinner – bananas

Pros And Cons Of The Mono-Diet


Weight Loss
Balanced Macronutrients
Allergen And Vegetarian Friendly


It Does Not Promote Healthy Eating Habits
Dangerously Restrictive
Could Result In Body Image Issues



Dieting for weight loss might be a little confusing, but finding a balance of foods to help shift the excess weight might prove to be a frustrating and complex undertaking. The mono diet promises to reduce much of this challenge. Eating just one type of food every day leaves out any guesswork on what you can prepare for meals. Not to mention it’s straightforward to follow.[v]

Since the mono diet doesn’t involve any food logging, calorie counting, or carb calculating, this absolves the follower much of the work which other weight loss diets depend on. The mono diet doesn’t require any calorie awareness or thinking.

Weight Loss

If you choose to eat only one type of food – even when that food is high in calories, it’s highly likely your calorie intake will increase throughout the day. You’ll most likely experience reduced bloating and quick water loss as a result. Also, you’re highly likely to lose muscle mass. Nevertheless, these weight loss results might be short term, and the lost weight might be regained in the long term.

Moreover, proponents of this diet say the program helps prevent cravings. However, in reality, avoiding specific foods might result in the desire for other foods that you’re not allowed to take while following this diet.[vi]

Balanced Macronutrients

Most diets promote focusing on just one macronutrient. For example, the keto diet is known for emphasis on low carb, high-fat meals. The mono diet is limited to eating one type of food for several days but doesn’t limit the quantities.[vii] This means you get to eat as much you want.

Allergen And Vegetarian Friendly

By default, the mono diet isn’t allergen-free or plant-based. Nonetheless, the nutrition guide offers multiple alternatives and substitutes to foods, which some people might not eat. For instance, meat should be swapped for beans or legumes.


It Does Not Promote Healthy Eating Habits

To lose weight and still maintain a healthy weight, it’s essential to find the best food for the body’s nutrition needs and learn the best way to manage the sizes. Also, you need to exercise, manage stress and get enough sleep. You also need support, whether it’s from professionals or peers. The mono diet doesn’t support these sustainable weight loss habits.[viii]

Dangerously Restrictive

Failure to eat a wide range of the foods that the body needs to get enough nutrients could have substantial health consequences. Severe restrictions resulting in fast weight loss could also cause dehydration, hair loss, menstrual irregularities, irritability, headaches, constipation, electrolyte imbalances, and gallstones. Health experts caution that the following mono diet might ultimately result in muscle loss, malnourishment, decreased metabolism, and fatigue.[ix]

Also, nutrition researchers warn that cutting out calories could result in compensatory behaviors like binge eating. It might occur, particularly if a person has low self-awareness to maintain the level of commitment needed in dietary restrictions.[x]

Could Result In Body Image Issues

Hunger management could be challenging. Some studies have found that severe restriction of calorie intake increases stress hampering weight loss aims. In a study conducted in 2016, researchers showed that college students are more likely to experience some compensatory behaviors, and some women might experience self-esteem issues because of the severe calorie restriction.[xi]

Is The Mono Diet A Healthy Option For You?

The United States department of agriculture’s dietary recommendations for Americans proposes eating different nutrient-dense foods, including nuts, seafood, eggs, lean protein, fortified soy products, lactose-free substitutes, dairy products, whole grains, fruits, legumes, and vegetables.[xii] Also, federal guidelines advise limiting beverages and foods with high amounts of sodium, saturated fat, and added sugar and limiting alcohol consumption.

Technically speaking, the mono diet falls short of these guidelines, mainly when the type of food you’ve chosen to eat is high in refined carbohydrates, sugars, or saturated fat, and no other types of foods can be eaten. Even if you could eat 3 different kinds of mono meals each day, you only get three different kinds of foods.

The United States department of agriculture recommends the daily intake of about 1,500 and 2,000 calories per day for weight loss and weight management, respectively, but these numbers might vary based on activity level, ethnicity, genetic background, sex, weight, and age.

It’s not possible to get enough calories from just one type of food, and this kind of unconventional diet plan doesn’t meet expert recommendations for a healthy balanced eating plan.

For instance, Penn’s potato mono-diet means that he probably only consumed 750 calories per day, which is less than what’s needed for a male of his height, even those looking to lose weight considering Penn is 6 feet, 6 inches). A man of his stature needs at least 1200 calories every day to remain healthy.[xiii]

How Much Does The Mono Diet Cost?

Although the mono diet is based on eating one type of food for a few days, there is no limit as to the amount of food you can eat. For instance, if you choose to follow the banana mono-diet, you should eat bananas for up to 12 days. However, you can eat as many bananas as you wish.

This might prove expensive in the long term since you will have to buy the food type you want to eat in considerable amounts. On the other hand, if you choose to follow the mono sweet potato diet, you’ll be required to only eat sweet potatoes for at least 5 days. This means you’ll have to buy sweet potatoes in large amounts.


What is the Main Health Benefit of the Mono Diet?

The mono diet is a very simple eating plan involving only one type of food or a group of food for all your meals. Proponents of this diet can increase fast weight loss.

What Foods Should I Eat in the Mono Diet?

Almost all foods can be eaten in the mono diet, including bananas, eggs, apples, and potatoes. Some variations of the mono diet involve choosing one type of food like legumes, vegetables, fruits, and meat.

Can Happens if You Only Eat One Kind of Food?

Eating only meat will ultimately force the body to start eating on your muscles. Also, if you stick to following a single type of food, you risk developing severe cases of scurvy.

How Was the Mono Diet Started?

The monotrophic diet became popular in 2016 thanks to YouTuber like Freelee. The YouTuber is known for going a few days only eating bananas.

Is the Monotrophic Diet Healthy?

Eating only one type of food isn’t healthy. The mono diet is a fat diet that promises weight loss, and that is all about it.

Does the Mono Diet Help Lose Weight?

There is no doubt that you can lose weight if you choose to follow the mono diet. The main problem is that it's only effective for short-term weight loss because eating the same food for a long time isn’t possible.



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