What Is the Mono Diet?

At Verywell, we believe there is no one-size-fits-all approach to a healthy lifestyle. Successful eating plans need to be individualized and take the whole person into consideration. Prior to starting a new diet plan, consult with your healthcare provider or a registered dietitian, especially if you have an underlying health condition.

What Is a Mono Diet?

The mono diet, also known as a monotrophic diet is a diet for which you only consume one type of food. Proponents claim that it can lead to quick and easy weight loss. But the claims are not rooted in any science, and there are plenty of science-backed reasons to avoid trying a mono diet. Your body needs a variety of nutrient-rich foods to function correctly.

What Experts Say

"People who follow the mono diet eat only one type of food (like bananas or potatoes) to try to lose weight. There’s no scientific evidence supporting this type of diet. Nutrition professionals warn it can lead to nutrient deficiencies and that any pounds shed will include lost muscle."
—Chrissy Carroll, RD, MPH

What You Can Eat

When you follow a mono diet, you eat only one food for several days or even weeks. There are different variations of the mono diet, including a banana mono diet, an egg mono diet, a potato mono diet, and even a chocolate mono diet. There are no official or formal rules for how to follow this type of diet; it's open to interpretation.

What You Cannot Eat

What you cannot eat depends on the type of mono diet you are following. You cannot eat anything other than the single food type you've chosen to eat on the mono diet.

How to Prepare the Mono Diet & Tips

Some people follow a mono diet by sticking with one group of foods such as fruit, vegetables, or meats. Others do mono meals, eating a single food for each meal, but eventually rotating that single food with others. Either way, meal planning is simple (in fact, it's unnecessary), since mono diets call for eating just one food or a very limited number of foods. Both in spite of and because of their simplicity, mono diets are not recommended for weight loss.

Pros of the Mono Diet

There are very few pros for a mono diet.

Simple to follow: Mono diets are simple to follow and take almost all of the planning and thought out of the dieting process.
May jump-start weight loss: A mono diet that limits calories may jump-start weight loss in the short term. For some people, this could increase motivation to continue losing weight with a more rounded eating and exercise plan.

Your energy levels will take a nosedive without proper nutrition. When you combine low energy, stress, and body dissatisfaction, going on a mono diet no longer seems simple or easy.

Cons of the Mono Diet

Mono diets are not recommended. There are many risks and drawbacks to following this type of diet.

Short-term weight loss: When you eat only one food—even if that food is high-calorie—your caloric intake plummets over the course of a day. You will probably experience quick water loss and decreased bloating as a result. You are also likely to lose muscle mass over time. However, these "weight loss" results are likely to be short-lived, and any weight loss is likely to be regained.
Increased cravings: Additionally, proponents of mono diets say these programs help to curb cravings. But in reality, avoiding certain foods can lead to a desire for the foods you can't have. This can rebound and lead to overeating.
Dangerously restrictive: There are significant health consequences when you don't eat a variety of foods to provide your body with nutrients. Severe restrictions leading to rapid weight loss can also cause gallstones, electrolyte imbalances, constipation, headaches, irritability, menstrual irregularities, hair loss, and dehydration. Experts caution that those following a mono diet will likely experience fatigue, decreased metabolism, malnourishment, and muscle loss.

May lead to binge eating: Nutrition researchers also warn that cutting back on calories can lead to compensatory behaviors, such as binge eating. This may occur especially when the person has a lowered ability to maintain the mindset associated with dietary restrictions.
Doesn't promote healthy habits: To both lose weight and maintain a healthy weight, it's important to determine the best foods for your nutritional needs and to learn how to manage portions. You also need to exercise, get enough sleep, and manage stress. And you need support, whether it's from peers or professionals. A mono diet does not support these healthy, sustainable habits.
Could lead to body image issues: Managing hunger can be challenging. In fact, studies have shown that severely restricting your caloric intake increases stress and hampers weight loss goals. In a 2016 study, researchers found that young college students were likely to experience compensatory behavior and that women were likely to experience dissatisfaction with their bodies as a result of severe calorie restriction.

You don't have to count calories, balance macronutrients, follow a program, and/or monitor portion sizes on a mono diet. While restricting calories may lead to weight loss, a mono diet does not support overall health and is not a solution for weight management.

Is a Mono Diet a Healthy Choice for You?

The U.S. Department of Agriculture 2020–2025 Dietary Guidelines for Americans recommends consuming a variety of nutrient-dense foods including all types of vegetables, legumes, fruits, whole grains, dairy products or lactose-free substitutes, fortified soy products, lean protein, eggs, seafood, nuts, and other healthy fats like oils. Federal guidelines also advise limiting foods and beverages with higher amounts of added sugar, saturated fat, and sodium, and limiting the consumption of alcohol.

Clearly, mono diets fall short of these standards, especially when the singular food of choice is high in saturated fat, sugars, or refined carbohydrates and no other foods are eaten. Even if you were to eat three different mono meals a day, you would only get three different kinds of food for that day.

The USDA suggests a daily intake of approximately 1,500 calories a day for weight loss and 2,000 calories a day for weight management, but these numbers can vary based on age, weight, sex, genetic background, ethnicity, and activity level.

It's not feasible to get a suitable number of calories from a single food, and this unconventional eating plan does not meet expert guidelines for healthy nutrition. At a minimum, you need 1,200 calories per day to stay healthy. Calculate your own daily calorie needs for weight loss with this tool.

Mono diets lack macro and micronutrients, such as protein, fiber, fat, vitamins, and minerals, which are critical for maintaining a healthy body. People who are only eating one food are not only cutting back on calories; they're also missing out on important nutrients.

A Word From Verywell

Due to their restrictive nature and inadequate supply of vital nutrients, mono diets are not recommended by health experts. While it may seem like a quick and simple approach to weight loss, denying your body of important macro and micronutrients is dangerous and can lead to a variety of health problems.

Setting up a healthy weight loss program may take time and effort, but it is a worthwhile investment. You're much more likely to feel better, enjoy a boost of body confidence, and have healthier outcomes when you follow a nutritious diet and exercise plan to lose weight.

Remember, following a long-term or short-term diet may not be necessary for you and many diets out there simply don’t work, especially long-term. While we do not endorse fad diet trends or unsustainable weight loss methods, we present the facts so you can make an informed decision that works best for your nutritional needs, genetic blueprint, budget, and goals.

If your goal is weight loss, remember that losing weight isn’t necessarily the same as being your healthiest self, and there are many other ways to pursue health. Exercise, sleep, stress management, mindful eating, and other healthful lifestyle factors also play a major role in your overall health. The best diet is always the one that is balanced and fits your lifestyle.