Keto Diet Explained: Food List (w/ Meal Plan), Benefits & Precautions

The ketogenic diet, often called the keto diet, is based on significantly reducing carbohydrate intake while increasing the consumption of fats and proteins. Foods such as bread and rice are largely eliminated, while fat-rich options become central to daily meals.

This dietary approach may support weight loss and has been used as part of the treatment of epilepsy and polycystic ovary syndrome. These effects are linked to its anticonvulsant properties, its ability to increase satiety, and its influence on blood glucose and hormone regulation.

Because it is a restrictive eating plan, the ketogenic diet should only be followed with guidance from a nutritionist. A full nutritional assessment is necessary to determine whether this diet can be followed safely and effectively.

How the keto diet works

The ketogenic diet should be followed with medical recommendation and nutritional supervision. It involves drastically reducing carbohydrate intake, usually to about 20 to 50 grams per day.

At the same time, the diet increases the intake of foods rich in fats, such as avocado, coconut, and olive oil. Protein intake should represent about 20% of total daily calories.

At the beginning of the diet, the body goes through an adaptation phase that may last several days or weeks. During this period, the body shifts from using carbohydrates to using fat as its main energy source, which may cause fatigue and headaches that usually improve once adaptation occurs.

A diet that is similar to the ketogenic diet is the low-carb diet. The main difference is that the ketogenic diet includes a much higher intake of fats.

What to eat

Foods that are allowed on the ketogenic diet include:

• Meats, such as turkey, chicken, beef, pork, and eggs;

• Fish and seafood, especially fatty fish such as salmon, sardines, and trout, as well as squid and shrimp;

• Low-carbohydrate vegetables, such as spinach, lettuce, broccoli, onion, watercress, cucumber, zucchini, cauliflower, tomato, asparagus, chicory, Brussels sprouts, pak choi, bell peppers, and bamboo or alfalfa sprouts;

• Low-carbohydrate fruits, such as blueberries, strawberries, raspberries, cherries, coconut, and avocado;

• Processed meats, such as ham, sausage, and salami;

• Oils and fats, such as olive oil, sunflower oil, grapeseed oil, coconut oil, and avocado oil, as well as butter or heavy cream;

• Nuts and nut butters, such as peanuts, walnuts, hazelnuts, Brazil nuts, almonds, and peanut, almond, or cashew butter;

• Seeds, such as flaxseed, chia, sesame, sunflower seeds, and olives;

• Dairy products, such as plain unsweetened yogurt, heavy cream, brie, parmesan, feta, cheddar, Swiss, mozzarella, and blue cheese;

• Seasonings, such as pepper, oregano, curry, and parsley;

• Beverages, such as coffee, tea, and water.

Unsweetened coconut, almond, or hazelnut beverages may also be consumed.

For people with a history of high blood pressure or high cholesterol, foods such as butter, heavy cream, and processed meats should be limited or avoided.

Foods that should be avoided

Foods that are not recommended on the ketogenic diet include:

• Grains, such as corn, oats, cornstarch, wheat flour, bread, toast, crackers, rice, and pasta;

• Legumes, such as beans, chickpeas, lentils, and soy;

• Tubers, such as potatoes, sweet potatoes, yams, and cassava;

• Sugary foods, such as cakes, filled cookies, chocolate, candy, ice cream, pies, and pudding;

• Simple sugars, such as white, brown, or demerara sugar, and honey;

• Alcoholic beverages, such as beer, wine, gin, rum, and cider.

Most fruits, except those listed above, are also discouraged because they are generally high in carbohydrates.

Diet foods that contain artificial sweeteners should also be avoided, as they may interfere with ketone production.

When consuming packaged foods, it is important to carefully check nutrition labels to confirm carbohydrate content and avoid exceeding the recommended daily intake.

3-day meal plan

The following table contains an example of a three-day keto diet meal plan:

It's important to note that the ketogenic diet should be carried out under the guidance of a registered dietitian, who can calculate the grams of carbohydrates that should be consumed per day. A dietitian can also help identify which foods are best for you to consume to achieve your goals. Because this can be a restrictive diet, it is important for a dietitian to help ensure you are getting adequate nutrients in your daily diet.

Health benefits

The main benefits of the ketogenic diet include:

1. May help control seizures

The ketogenic diet increases the production of ketone bodies, such as acetoacetate, acetone, and beta-hydroxybutyrate. These substances can reach the brain and may have anticonvulsant effects.

For this reason, the ketogenic diet may significantly reduce seizure frequency in adults and children with epilepsy who do not respond to standard treatments. It should always be prescribed and monitored by a neurologist.

Despite these findings, more high-quality scientific studies are still needed to confirm its effectiveness for seizure control.

2. Supports weight loss

The ketogenic diet may promote weight loss by increasing satiety. Fats and proteins take longer to digest, which helps reduce hunger throughout the day.

In addition, higher levels of beta-hydroxybutyrate and acetone may help suppress appetite, further supporting weight loss.

3. May help prevent and manage diabetes

The ketogenic diet may help prevent and manage well-controlled type 2 diabetes by improving blood glucose levels, insulin sensitivity, and hemoglobin A1c.

People who take diabetes medications should consult their doctor before starting this diet to avoid potential complications.

4. May support neurodegenerative disease management

The ketogenic diet may also support the management of neurodegenerative conditions such as Alzheimer’s disease and Parkinson’s disease.

This effect is linked to increased ketone production, which can improve the brain’s energy efficiency and enhance its antioxidant defenses.

5. May help manage polycystic ovary syndrome

Some studies suggest that the ketogenic diet may help manage polycystic ovary syndrome by promoting weight loss and improving hormonal and blood glucose balance.

Keto diet and cancer treatment

The ketogenic diet may support cancer treatment by limiting glucose availability, which is a primary energy source for cancer cells. This mechanism may contribute to reduced tumor growth.

However, most studies on the ketogenic diet and cancer have been conducted in laboratory settings or in animals. Human studies are limited in number, involve small sample sizes, and are short in duration.

As a result, more high-quality human studies are needed to determine whether the ketogenic diet is effective as part of cancer treatment.

Possible risks

Potential long-term risks of the ketogenic diet include:

• Fatty liver disease;

• Loss of muscle mass;

• Kidney stones;

• Cardiovascular disease;

• Deficiencies of vitamins, minerals, and phytonutrients.

Short-term symptoms such as nausea, vomiting, headache, fatigue, mood changes, dizziness, insomnia, and constipation may also occur and can last for days or weeks.

Who should not follow it

The ketogenic diet is not recommended for adults over 65, children, adolescents, or for people who are pregnant or breastfeeding.

It should also be avoided by people at increased risk of ketoacidosis, including those with type 1 diabetes, uncontrolled type 2 diabetes, pancreatitis, low body weight, liver or kidney disease, heart conditions, primary carnitine deficiency, carnitine palmitoyltransferase deficiency, carnitine translocase deficiency, porphyrias, or pyruvate kinase deficiency.

People with gallstones or those using corticosteroid-based medications should only follow the ketogenic diet with medical approval and close nutritional monitoring.