A no-carb diet may provide certain benefits, including lowering blood pressure. But this diet can also cause side effects and may be difficult to sustain.

A no-carb diet is an extreme version of low carb dieting. It eliminates almost all carbs, including whole grains, fruits, and vegetables.

While studies show that decreasing your carb intake can help you shed pounds and may have health benefits, completely eliminating carbs is highly restrictive and most likely unnecessary.

This article provides a detailed overview of a no-carb diet, including its potential benefits, downsides, and foods to eat and avoid.

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.

A no-carb diet resembles a ketogenic diet, which limits your carb intake to fewer than 20-50 grams (g) per day and encourages you to get about 60% or more of your daily calories from fat.

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

Simply put, when you follow a no-carb diet, you avoid all high carb foods.

Specifically, try to eliminate whole and refined grains, baked goods, fruits, milk, yogurt, beans, legumes, pasta, bread, sugar-sweetened beverages, and starchy vegetables like peas and corn.

Food and drinks allowed on a no-carb diet include meat, fish, eggs, cheese, butter, oils, water, and plain coffee or tea.

If you’re less stringent, you can also eat nuts, seeds, non-starchy vegetables, and high fat fruits like avocado and coconut since these foods are low in net carbs.

Since this diet focuses on restricting a specific macronutrient, there are no recommendations for daily calorie intake or portion sizes.

In general, reducing your carb intake can help you lose weight.

Replacing carbs with primarily more protein, as wellas fiber and fat, may help you feel more full and eat fewer overall calories, which in turn promotes weight loss.

The research is still mixed on whether reducing your carb intake is better for weight loss and health. Some studies have suggested this to be the case in the first 6 months but not as much in the long term.

Therefore, you likely don’t need to completely eliminate carbs to achieve weight loss. Gradually reducing your carb intake and, more importantly, decreasing your overall calorie intake are less restrictive ways to lose weight.

What happens if you don’t eat carbs for a week?

Very low carb diets typically promote rapid weight loss in the first few weeks.

However, this is usually due to a quick drop in water weight because every gram of carbs holds approximately 3 g of water in your body.

No studies exist on diets that completely eliminate carbs, but research on very low-carb and ketogenic diets suggests that they may have several benefits.

  • Cardiovascular health: Decreasing your carb intake may improve heart health. Very low carb diets have been shown to decrease blood triglyceride levels, which can increase your chance of heart disease. Even so, more research is needed.
  • Blood glucose: Cutting carbs — particularly refined carbs and sugar — can aid blood sugar control, which may be especially helpful for people with diabetes.
  • Blood pressure: Some studies suggest reducing carb intake can help lower blood pressure.
  • Reduction of belly fat: Limited research indicates that very-low-carb diets are better than low fat diets at decreasing belly fat, a type of fat associated with inflammation and certain diseases.
  • Metabolic syndrome: Decreasing carb intake is linked with a lower chance of metabolic syndrome, a group of risk factors that increase the likelihood of developing heart disease, diabetes, and stroke.

A no-carb diet may have a number of downsides.

  • Constipation: Since a no-carb diet restricts fruits, most vegetables, beans, and whole grains, it can be very low in fiber, which helps digestion by helping maintain bowel regularity. Because of this, a no-carb diet may lead to constipation.
  • Low energy: Carbs are your body’s primary source of energy. Therefore, a no-carb diet may lead to low energy and fatigue.
  • Insufficient nutrients: A no-carb diet may not provide enough vitamins and minerals, such as potassium, B vitamins, and vitamin C, which are abundant in fruits, vegetables, and other plant foods. Additionally, the increased urination that results from restricting carbs may lead to nutrient deficiencies such as sodium and potassium over time.

Can you survive on a no carb diet?

If you’re following a diet that still allows foods very low in net carbs, then you’re basically following a variation of the ketogenic diet. Research shows that as long as you’re getting all the necessary nutrients, you should be able to remain healthy long-term.

On the other hand, if you’re excluding carbs entirely, the long-term impact isn’t as clear. Research suggests that eating only animal proteins, for example, causes few negative side effects, though some people did develop higher Low-density lipoproteins (LDL) or bad cholesterol levels.

Excluding carbs doesn’t necessarily mean excluding all plant foods. However, the research on this subject is limited. Another 2020 study only examined whether it is possible to survive by only eating animal proteins. The authors concluded that your calcium may become compromised over time, among other possible adverse effects.

In short, you are likely to survive without carbs in the sense that you won’t starve to death, but it’s unclear what the long-term health consequences might be.

As the no-carb diet is highly restrictive, very high in fat, and not well researched for safety, it’s not appropriate for those with eating disorders, children, cholesterol hyper-responders, and pregnant or nursing people.

Due to a lack of sufficient research, it’s a good idea to consult with your doctor and to be monitored by a healthcare professional as long as you are excluding carbs from your diet.

Foods that are typically allowed on a no-carb diet include:

  • Meat and low carb animal products: chicken, beef, turkey, lamb, venison, bison, pork, eggs, butter, lard, cheese
  • Seafood: salmon, tilapia, cod, shrimp, sardines, herring, crab
  • Seasonings: herbs and spices
  • Zero-calorie beverages: water, black coffee, and plain tea
  • Nuts and seeds (those low in net carbs): almonds, walnuts, pumpkin seeds, sunflower seeds, pistachios, cashews
  • Non-starchy vegetables (those low in net carbs): broccoli, zucchini, bell peppers, cauliflower, leafy greens, rutabaga, turnips, Brussels sprouts, asparagus, mushrooms
  • High fat fruits: coconut, avocado

A no-carb diet is highly restrictive and eliminates several food groups, such as:

  • Grains: rice, farro, barley, quinoa, wheat, bread, pasta
  • Sweets and baked goods: cakes, cookies, candy, sodas, sugary drinks
  • Fruits: apples, oranges, bananas, berries, kiwi, pears
  • Starchy vegetables: peas, corn, squash, potatoes
  • Beans and legumes: black beans, kidney beans, chickpeas, lentils
  • Dairy: milk and yogurt
  • Condiments with added sugar: ketchup, barbecue sauce, salad dressings
  • Alcohol: beer, wine, liquor, sugary mixed drinks

Here is a sample five-day menu for a no-carb diet.

Day 1

  • Breakfast: eggs, bacon, sliced avocado
  • Lunch: romaine lettuce with ground turkey, cheese, and olive oil dressing
  • Dinner: salmon, zucchini noodles, side of sunflower seeds
  • Snacks: beef jerky, cheese

Day 2

  • Breakfast: eggs, steak, bell pepper strips
  • Lunch: tuna-fish lettuce wraps, carrots dipped in mashed avocado
  • Dinner: lamb chops, spinach salad with walnuts, and olive oil dressing
  • Snacks: hard-boiled eggs, pistachios

Day 3

  • Breakfast: eggs, turkey sausage, avocado
  • Lunch: scallops, Brussels sprouts roasted with Parmesan cheese
  • Dinner: pork chops, roasted tomatoes, and turnips
  • Snacks: sunflower seeds, brie

Day 4

  • Breakfast: eggs with shredded chicken, jalapeño, cheddar cheese
  • Lunch: turkey burger patties with rutabaga fries
  • Dinner: meatballs and zucchini noodles with roasted tomatoes
  • Snacks: sardines, macadamia nuts

Day 5

  • Breakfast: cheesy eggs with broccoli, chicken sausage
  • Lunch: flank steak and arugula salad with olive oil dressing, cashews
  • Dinner: coconut-crusted shrimp, roasted asparagus, and mushrooms
  • Snacks: turkey jerky, avocado

A no-carb diet eliminates almost all carbs and encourages high intakes of fat and protein.

It may boost weight loss, heart health, and blood sugar control. Yet, it’s unnecessary to cut all carbs to experience these benefits.

Plus, this diet may reduce energy levels and increase your risk of nutrient deficiencies.

Instead, aim to eat a balanced diet with a variety of foods.