Eliminate Carbs for 3 Days - Use Protein and Fat for Energy Instead - See What Happens...,

healthline |  A no-carb diet is a way of eating that eliminates digestible carbs as much as possible.

Carbs are your body’s primary source of energy. They’re found in grains, beans, legumes, fruits, vegetables, milk, yogurt, pasta, bread, and baked goods.

Therefore, someone on a no-carb diet must avoid most of these foods and instead eat foods that contain primarily protein or fat, such as meats, fish, eggs, cheese, oils, and butter.

There is no strict rubric for a no-carb diet. Some people who follow it eat nuts and seeds, non-starchy vegetables, and high-fat fruits like avocado and coconut.

Even though these foods have some carbs, they’re high in fiber. Therefore, they have only a minuscule number of digestible or net carbs, which is calculated by subtracting the amount of fiber from the total number of carbs (1).

A no-carb diet resembles a ketogenic diet, which limits your carb intake to fewer than 30 grams per day and encourages you to get 70% or more of your daily calories from fat (2Trusted Source). 

Depending on what you choose to eat, a no-carb diet can be more restrictive than keto.