Healthline diet score: 2.83 out of 5

In 2013, the Omni Diet was introduced as an alternative to the processed, Western diet that many people blame for the rise in chronic disease.

It promises to restore energy levels, reverse symptoms of chronic disease, and even help you lose 12 pounds (5.4 kg) in as little as 2 weeks. 

Despite criticism from experts for being a restrictive diet, many people have reported positive results, and you may wonder whether this diet will work for you.

However, it’s important not to confuse the Omni Diet with the Omnitrition Diet, as these are two separate programs with very different protocols.

This article reviews the benefits and downsides of the Omni Diet and whether science backs its claims.

diet review scorecard
  • Overall score: 2.68
  • Weight loss: 3.0
  • Healthy eating: 3.75
  • Sustainability: 1.5
  • Whole body health: 2.0
  • Nutrition quality: 3.75
  • Evidence-based: 2.0

BOTTOM LINE: The Omni Diet promotes eating whole, unprocessed foods, regular exercise, and other healthy behaviors. Still, its high cost and large list of restrictions make it difficult to follow long term.

What is the Omni Diet?

The Omni Diet was established by registered nurse Tana Amen after a life-long struggle with chronic health issues and battle with thyroid cancer at the age of 23.

By the time Amen reached her thirties, she had an array of health issues, including hormonal imbalances, insulin resistance, high cholesterol, and chronic fatigue. After taking endless medications, she decided to take control of her health and developed the Omni Diet.

Though believing a vegetarian lifestyle was the healthiest option, she soon realized that her insulin and cholesterol levels were not improving and many of the vegetarian foods she was eating were highly processed with a long list of unnatural ingredients.

Then, she shifted to the other end of extremes by adopting a sugar-free, grain-free animal-protein diet. Though her energy levels improved, she felt she was missing essential nutrients from plants.

Finally, she shifted her focus toward a balanced approach that allowed both plant and animal foods in moderation — also commonly referred to as a flexitarian diet

The Omni Diet focuses on eating 70% plant foods and 30% protein. Though protein is a macronutrient that comes from both plant and animal sources, the diet refers to protein mostly as lean meats.

Though the diet welcomes both plant and animal products, it has many restrictions. For example, dairy, gluten, sugar, soy, corn, potatoes, and artificial sweeteners are not permitted. 

By following the Omni Diet, Amen states she has transformed thousands of lives by decreasing inflammation, reducing or eliminating symptoms of chronic disease, optimizing brain function, and improving fullness without feeling deprived.

Summary

The Omni Diet comprises 70% plant foods and 30% proteins — mostly from lean meats. The diet promises to decrease inflammation, increase brain function, and reduce or eliminate symptoms of chronic disease.

How to follow the Omni Diet

The Omni Diet is a 6-week program that consists of three phases. Phase 1 and 2 are highly restrictive, while Phase 3 allows the gradual reintroduction of foods.

Phase 1

The first phase of the Omni Diet focuses on transitioning off of the Standard American Diet (SAD), which consists of mostly processed, high fat, and high sugar foods.

The main rules of the diet include:

  • Only eat foods allowed on the diet.
  • No foods on the forbidden list should be consumed.
  • Limit yourself to a 1/2-cup serving (about 90 grams) of fruit per day.
  • Avoid desserts and other restricted items.
  • Drink a meal-replacement smoothie — ideally the Omni Diet green smoothie.
  • Eat protein every 3–4 hours.
  • Drink water over other beverages.
  • Visit a sauna twice per week to detox your system. 

Over the first 2 weeks, you’ll eat from a list of permitted foods and avoid eating foods on the forbidden list. Your diet should consist of 30% protein (mostly lean meats), while the remaining 70% should come from plants.

Smoothies should have a 4-to-1 ratio of vegetables to fruit, or ideally no fruit at all. They should also include a healthy fat and at least 20–30 grams of protein. Recipes are provided in “The Omni Diet” book.

You should aim to drink 50% of your body weight in ounces of water daily (but no more than 100 ounces per day). For example, a 150-pound (68-kg) person should consume 75 ounces (2.2 liters) of water per day.

Finally, Amen encourages followers of the diet to take daily supplements, such as vitamin D, magnesium, probiotics, and omega-3. She also promotes a line of supplements developed by her husband, Dr. Daniel Amen.

Phase 2

During the second 2-week phase, Phase 2, you’re encouraged to continue with the rules of Phase 1 but allowed to eat unprocessed desserts that don’t contain any added sugar or white flour. The book provides a list of examples, such as dark chocolate.

In addition, you’re expected to exercise daily. The book recommends starting with 30 minutes of walking per day and gradually increasing to a 30-minute full-body workout, which is provided in the book.

Phase 3

This 2-week phase allows more flexibility in terms of food choices and is the last phase of the program. As long as you’re following the diet 90% of the time, 10% of foods from the non-permitted list are allowed but discouraged.

If you must indulge, Amen recommends following the “three-bite rule,” which involves taking three bites of a forbidden food, enjoying it, and throwing the rest away.

Alcohol is allowed to be reintroduced but discouraged. You can drink up to two 5-ounce (150-mL) glasses of wine per week but must avoid any alcoholic beverages that contain sugar or gluten, such as beer or mixed cocktails.

You’re allowed to enjoy foods during times of celebration, such as a wedding, birthday, or anniversary. However, you’re expected to plan ahead and only select one forbidden food that you can enjoy. Still, it states that you shouldn’t feel guilty about your choices.

This phase should be followed for a least 2 weeks but ideally indefinitely.

Summary

The Omni Diet involves three 2-week phases, which must be followed to see results. The first two phases are the most strict, while the final phase allows for slightly more flexibility. The third phase may be followed indefinitely.

Foods to include and avoid

The Omni Diet provides a detailed list of foods to include and avoid.

Foods to eat

  • Non-starchy vegetables: arugula, artichokes, asparagus, avocado, beets, bell peppers, bok choy, broccoli, Brussels sprouts, cabbage, carrots, cauliflower, celery, chard, chicory, collard greens, cucumber, eggplant, fennel, garlic, jicama, kale, and lettuce, mushrooms, onions, radishes, spinach, sprouts, squash (all types), tomatoes, zucchini, and others
  • Meat, poultry, and fish: lean, organic, grass-fed, hormone-free, antibiotic-free varieties (e.g., skinless chicken and turkey; lean beef, bison, lamb, and pork; and wild fish and shellfish like clams, halibut, herring, mackerel, mussels, salmon, scallops, shrimp, tilapia, trout, and tuna)
  • Protein powder: sugar-free pea or rice protein powder (those sweetened with stevia are permitted)
  • Eggs: cage-free, omega-3 eggs (yolks and whites permitted)
  • Fats and oils: plant-based oils like almond, coconut, grapeseed, macadamia nut, and olive oils (must be organic, cold-pressed, and unrefined)
  • Raw, unsalted nuts and seeds: all types are permitted, including their butters
  • Flours: non-grain flours made of nuts and seeds (e.g., almond flour)
  • Herbs and spices: all kinds are permitted, can be fresh or dried
  • Sweeteners: only stevia extract is permitted in small amounts
  • Beverages: water, green tea, and unsweetened plant milks like almond, coconut, hemp, and rice milk
  • “Omni NutriPower” foods: cacao powder and nibs (must be 100% pure, “Dutch processed,” and unroasted), coconut and its products (water, milk, meat, butter, oil), goji berries and powder, macadamia nuts and its products (oil, butter), pomegranate (whole and powdered form), and wheatgrass

Foods to limit

  • Fruit: choose fresh or frozen berries most often (raspberries, blueberries, blackberries, and strawberries), other fruits are allowed occasionally (e.g., apples, apricots, bananas, cantaloupe, cherries, dragonfruit, grapes, grapefruit, kiwi, lemon, lychee, lime, mangoes, melons, oranges, peaches, pears, pineapple, pomegranates, and watermelon)
  • Non-gluten grains: brown rice, sprouted Ezekiel bread, pseudocereals (amaranth, buckwheat, and quinoa), steel-cut oats, and tortillas
  • Plant protein: all beans and lentils must be dried, soaked overnight, and cooked before eating (not permitted in first two phases)
  • Cooking oils: canola, corn, ghee, safflower, and vegetable oils (try to limit as much as possible)
  • Sweeteners: limit sugar alcohols (xylitol is the best option), honey must be raw and unpasteurized (use it in small amounts)
  • Coffee: one 5–6 ounce (150–175-mL) serving of coffee per day before 12:00 p.m. is allowed

Foods to avoid

  • Vegetables: white potatoes
  • Carbohydrates: all simple carbs (e.g., breakfast cereals, instant oatmeal, most breads, and white flour, sugar, pasta, and rice), and grains (e.g., barley, corn, rye, and wheat)
  • Animal protein: pork, ham, commercially raised beef and poultry, farm-raised fish, and all processed meats (e.g., bacon, luncheon meats, pepperoni, and sausage)
  • Plant protein: soy-based foods (milk, protein bars, protein powder, oils, and byproducts, etc.)
  • Dairy: all dairy products should be avoided (butter, cheese, cream, ice cream, milk, and yogurt) — however, ghee is permitted
  • Corn-based products: high fructose corn syrup, corn oil, popcorn, cornstarch, and corn chips
  • Processed food: baked goods (e.g., croissants, donuts, and muffins), cakes and cupcakes, candy, chips (potato, veggie, and nacho), cookies, fast food, frozen dinners, nutrition bars, and sugar-free foods and candies
  • Sweeteners: all processed sugar (brown and white sugar, agave, and processed maple syrup), artificial sweeteners (e.g., aspartame, saccharin, and sucralose), jams, jellies, and marmalades
  • Beverages: all types of juice (even 100% juice), energy drinks, lemonade, fruit punch, and regular and diet sodas
  • Condiments: any that contain restricted ingredients (e.g., barbecue sauce, ketchup, and soy sauce)
  • Genetically-modified (GMO) foods: all GMO foods should be avoided 
Summary

The Omni Diet encourages eating whole, unprocessed foods while avoiding dairy, gluten, grains, beans, lentils, potatoes, corn, sugar, and a long list of other forbidden foods.

Can it help you lose weight?

One of the biggest claims of the Omni Diet is that it can help you shed 12 pounds (5.4 kg) in 2 weeks.

The Omni Diet focuses on whole, minimally processed foods and emphasizes protein. Eating more fiber-rich vegetables, healthy fats, and proteins has been shown to encourage weight loss by promoting feeling fuller on fewer calories (1, 2).

Since the diet has a large list of restrictions that includes many ultra-processed foods that are high in fats and sugars, you’ll be eating fewer calories than before you started. Also, adding more exercise to your routine further promotes a calorie deficit.

However, despite the emphasis on avoiding dairy, gluten, and grains, limited research demonstrates that doing so is necessary for weight loss. 

In fact, most research suggests that the most successful weight loss programs focus on eating fewer processed foods and eating greater amounts of vegetables, fruits, and whole grains, rather than eliminating certain food groups or macronutrients (2, 3, 4).

Despite the positive changes to their diet, the rapid weight loss most people on the Omni Diet experience isn’t due to just losing belly fat but rather a combination of losing water, fat, and muscle mass (2, 5).

When a person eats fewer calories, they begin using stored energy known as glycogen, which holds onto large amounts of water — 1 gram of glycogen holds 3 grams of water. As the body burns glycogen, it releases water, leading to a rapid decrease in weight (6, 7).

Moreover, a small amount of muscle loss may also occur. Considering muscle also holds onto water, this may lead to additional water loss (6, 7).

After this large and rapid drop in weight, most people experience a smaller and more steady weight loss of around 1–2 pounds (0.45–0.9 kg) per week, which is due to the body adjusting to the change in calorie intake and number of calories burned (6, 7).

However, most medical experts agree that losing weight too quickly can be risky and ultimately lead to weight regain. Therefore, it’s best to focus on slow, gradual weight loss.

Nonetheless, increasing your daily exercise, eating fewer processed foods, and opting for healthier food choices are positive changes that can lead to meaningful weight loss over time.

Summary

By eating more whole, unprocessed foods and exercising regularly, you will likely lose weight on the diet, especially if you stick to it long term. Yet, the rapid weight loss that’s promised is most likely due to losing water weight rather than fat.

Potential benefits

Though many people start the Omni Diet for weight loss, there are other potential benefits to it.

Whole, unprocessed food

The Omni Diet largely focuses on consuming a diet full of whole, unprocessed foods.

Most health experts agree that limiting your intake of ultra-processed foods is beneficial for health, as these foods tend to be high in unhealthy fats, sugars, and empty calories (8, 9).

Eating a diet full of vegetables, lean proteins, and healthy fats is linked to better health outcomes, such as a lower risk of obesity, heart disease, diabetes, inflammation, and certain types of cancer (10, 11, 12, 13).

In fact, one large study that followed 105,159 participants for a median of 5.2 years found that for every 10% increase in calories from ultra-processed foods, they had a 12% and 13% increased risk of cardiovascular disease and coronary heart disease, respectively (14).

Therefore, any diet that promotes consuming more whole, unprocessed foods will likely benefit your health.

No calorie counting

As long as you follow the 70/30 diet guide, you aren’t expected to count calories on the Omni Diet, which focuses on the nutrient quality of each meal, rather than its calorie count. 

Since most foods on the diet are high in fiber and protein, they may help you control your hunger and food intake, as they take longer to digest. The diet also promotes an intuitive approach to eating by allowing yourself permission to eat when your body signals it’s hungry (15).

However, intuitive eating is most successful when there are no food restrictions. Considering this diet has a large list of off-limit foods, it may increase anxiety surrounding food choices, and it ultimately ignores the premise of listening to what the body wants (16, 17, 18).

Focus on lifestyle changes

Unlike most diets, the Omni Diet encourages a holistic approach to health.

In addition to changing your diet, Amen provides healthy cooking tips and teaches readers how to make healthy food choices, read labels, and exercise portion control. 

She also encourages regular exercise, practicing gratitude, and stress-management techniques, such as meditation.

Summary

The Omni Diet encourages eating more whole, unprocessed foods, which are linked to better health and weight management. The diet also encourages listening to your body’s natural hunger cues and embraces a holistic approach to health.

Potential downsides

Despite reported success stories, the Omni Diet has many downsides.

Highly restrictive

Although Amen promises to decrease feelings of hunger and deprivation, the diet has a long list of restrictions.

To follow the diet correctly, you must eliminate or greatly reduce your intake of dairy, gluten, grains, sugar, starchy vegetables, beans, lentils, and all premade foods and desserts.

For most people, this leaves little room for flexibility and ignores other important aspects of eating, such as culture, tradition, and celebration. For example, beans and lentils make up a large portion of the diet for certain cultural groups, yet they’re highly discouraged.

The most successful diets are those that are affordable, culturally acceptable, and enjoyable — and can be followed long term (1, 2).

Diet-centered messaging

Although the book claims to take a balanced approach, it encourages a number of concerning behaviors and messages.

For example, the “three-bite rule” limits a person to only three bites of a dessert or off-limit food. While the idea is to enjoy the flavor without the calories and sugar, this type of behavior does not embrace balance.

Moreover, the book regularly uses terms such as “toxin” and “poison” to portray foods as being harmful and bad, which further perpetuates the “good versus bad” mentality of dieting. Ultimately, this can promote feelings of guilt and a bad relationship with food.

In fact, those who describe food using moralistic terms, such as “good” and “bad” have been shown to have less healthy eating and coping behaviors, such as stress eating, than those who do not use those terms (19).

Due to the overly restrictive nature of the diet and its focus on vilifying food, it may lead to a negative relationship with food, especially in those with a history of disordered eating (20).

Expensive and inaccessible

Amen recommends a long list of organic foods and supplements that are usually more expensive and inaccessible to many. 

In addition, she discourages inexpensive food items, such as beans, lentils, potatoes, corn, and dairy products, which are cost-effective and nutritious (21, 22). 

This diet also requires regular use of a sauna as a detox — despite a lack of evidence that it will detox your body. Many people do not have regular access to a sauna or cannot afford it financially, making this lifestyle even harder to achieve (23).

Summary

The Omni Diet is very restrictive, expensive, and inaccessible to many groups of people. Despite its claims of encouraging a balanced lifestyle, it promotes disordered eating behaviors and has a diet-centric approach.

The bottom line

The Omni Diet has become popular for its claim as a balanced approach to eating.

It embraces a holistic lifestyle that consists of eating whole foods, exercising regularly, managing stress, and other healthy behaviors. Together, these may help you lose weight, especially if you do not normally follow this type of lifestyle.

However, the diet has many restrictions that are not supported by science and ultimately make the diet extremely difficult to follow long term.

Though the diet has some redeeming qualities, there are other healthy and more sustainable diets available.