A Zero-Carb Diet: All You Need to Know

What Is a Zero-Carb Diet?

A zero-cab diet eliminates all carbohydrate sources from the diet, i.e., no sugar, vegetables, fruits, or anything that contains carbs. But should we eliminate all carbohydrates?

Although low-carb diets lead to almost the same results, a zero-carb diet aims to induce, promote, and maintain ketosis, the bodily process of burning fat (ketones) instead of carbohydrates (glucose) to produce energy.

Burning fat instead of carbohydrates can have various health benefits, including [1] [2] [3]:

• Decreased Inflammation,
• Weight Loss,
• Better Insulin Resistance,
• Improved Mental Health,
• Reduced Symptoms of Alzheimer’s Disease,
• Improve Lipid Profiles,
• Reversed Metabolic Syndrome,
• Supplement Cancer Treatments, and
• Boost Longevity.

There isn’t just one type of a zero-carb diet, and it can be a version of many ketogenic or animal-based diets.

Types of Zero-Carb Diet

There are many zero-carb diets, each with its own specific rules and goals. Some of the most popular zero-carb diets include

• The Keto (Ketogenic) Diet: A high-fat diet that focuses on high-quality protein sources and allows limited amounts of non-starchy vegetables.
• The Carnivore Diet: A meat-based elimination diet focusing on high-fat and moderate-protein animal products like meat, poultry, fish, and limited dairy, and avoiding all plant-based foods, from vegetables and fruits to grains and nuts.
• The Atkins Diet: This diet starts with minimized carbohydrates and phases to gradually reintroduce carbs.
• The Paleo (Paleolithic) Diet: Focuses on whole foods, lean meats, fish, fruits, vegetables, nuts, and seeds while excluding grains and processed foods.
• Zero-Carb Fasting: Intermittent fasting has many different types, including a 96-hour fast, 72-hour fast, 60-hour fast, 48-hour fast, 40-hour fast, 36-hour fast, 20-hour fast, 24-hour fast, 18-hour fast, 16-hour fast, 12-hour fast, and zero-carb fasting. In zero-carb fasting, you need to avoid all calorie sources, including carbohydrates.

Going on a zero-carb diet can positively impact your health, as it can help decrease inflammation, support digestive health, boost fat melt and weight loss, improve heart health, and control blood sugar levels. 

Health Benefits of a Zero-Carb Diet

Although a zero-carb diet includes avoiding different foods you may be used to eating, it can help you modify your eating habits by eliminating unnecessary foods, which can provide the following benefits.

A Zero-Carb Diet Can Decrease Inflammation

Various studies indicate that a zero-carb ketogenic diet can have anti-inflammatory effects by suppressing nuclear factor kappa-light-chain- enhancer of activated B cells (NF-kB) activation and nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3) inflammasome [4] [5] [6].

Also, a 2024 study indicates that a ketogenic diet can improve some of the markers related to inflammation, including TNF-α and IL-6 [7].

A Zero-Carb Diet Can Improve Digestive Health

A 2010 study showed that a very low-carb diet can positively affect the quality of life, alleviate abdominal pain, improve stool habits, and relieve patients dealing with diarrhea-predominant irritable bowel syndrome (IBS-D) [8].

Also, a 2000 study on 239 participants with IBS or non-specific functional bowel complaints indicated that avoiding sorbitol, lactose, or fructose for 30 days could alleviate IBS symptoms [9].

A 1998 study on IBS patients indicated that they were dealing with abnormal colonic fermentation of carbohydrates, which was improved after eliminating harmful carbohydrates [10].

A Zero-Carb Diet Can Boost Fat Melt and Weight Loss

Consuming fat and protein instead of carbohydrates can help you feel more satiated, so you consume fewer calories, which leads to weight loss [11] [12] [13].

Also, going on a very low-carb diet causes water weight loss, which leads to quick weight loss because every gram of carbohydrates in your body contains about three grams of water [14] [15].

Additionally, a 2003 study on the impact of carbohydrate-restricted diets on weight loss indicated that obese participants who had metabolic syndrome or diabetes lost more weight during six months on a low-carb diet than on a low-calorie and low-fat diet.

Also, the low-carb diet helped the participants improve insulin sensitivity and triglyceride levels [16].

A Zero-Carb Diet Can Improve Heart Health

Zero-carb diets can lower blood triglyceride levels, which directly affects heart health, as high triglyceride levels can negatively impact heart health [17] [18].

A 2006 study on carbohydrate-restricted diets showed that weight loss resulting from restricting carbs could change plasma lipoproteins secretion and processing and particles related to lower risk for atherosclerosis and coronary heart disease [19].

A Zero-Carb Diet Can Help Control Blood Sugar Levels

Consuming carbohydrates can cause fluctuations in blood sugar levels, so cutting carbs can help stabilize blood sugar levels, which is necessary for diabetic patients [20].

A 2008 study on the impact of low-carb, ketogenic diets versus low-glycemic index diets on glycemic control in type 2 diabetes patients indicated that low-carb diets could greatly improve glycemic control and lower or eliminate medications compared to low-glycemic index diets [21].

Despite all these health benefits, a zero-carb diet may cause temporary side effects in some individuals. So, it’s wise to know about them and modify our approach accordingly to minimize unwanted side effects.

Side Effects of a Zero-Carb Diet

During the initial stages of going on a zero-carb diet, your body, especially your digestive system, goes through changes to adapt to the new dietary situation.

During this phase, some individuals may experience side effects, like constipation, diarrhea, low energy levels, nausea, and headaches, which usually fade away in a week or two as your body adapts to the new eating habits.

Constipation

Cutting carbohydrates includes eliminating water-rich vegetables and fruits, which can affect the digestive system and cause irritations like constipation.

A 2013 study indicated that consuming more liquids can help cure constipation and alleviate symptoms [22].

Diarrhea

A 2005 study shows that going on a zero-carb diet can cause gastrointestinal disruptions, including nausea/ vomiting, diarrhea, and constipation associated with gastritis and fat intolerance [23].

Low Energy Levels

Carbohydrates are the primary energy source for individuals who consume them. Shifting to a zero-carb diet may cause low energy levels in the early days of adapting to a zero-carb lifestyle [24].

Nausea and Headaches

Eliminating carbohydrates can make changes in metabolism, which can lead to nausea, headaches, and disrupted sleep in the short term [25].

The important point is that some groups of people are more prone to side effects of an elimination diet due to their specific situation and needs.

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Who Should NOT Do a Strict Zero-Carb Diet?

• Individuals with Underlying Medical Conditions: Those dealing with kidney issues, liver problems, or metabolic disorders should consult a healthcare professional before adopting a zero-carb diet, as changing diets can affect their health condition. For example, consuming too much protein from animal-based sources may have negative impacts on the kidneys of sensitive individuals. Also, big dietary changes can cause digestive issues.
• Pregnant or Breastfeeding Women: These individuals have increased nutritional needs, and a zero-carb diet may not provide sufficient nutrients for both the mother and the developing child. It’s best to consult a healthcare specialist to modify the diet based on their specific needs.
• Athletes and Active Individuals: Carbohydrates are a primary source of energy, and intense physical activity may require higher carb intake. A zero-carb diet might not support peak athletic performance.
• Those with a History of Eating Disorders: Strict diets may trigger or exacerbate eating disorders, so it's best for these individuals to consult their physicians first.
• Individuals with Digestive Issues: Those with sensitive guts need to eat and avoid foods that can help their digestion, meaning that such individuals cannot make sudden big changes in their diets without consulting healthcare professionals.

If you’re among these sensitive groups or anyhow wish to try a zero-carb diet, you should know what exactly you should eat and avoid.

Zero-Carb Diet Food List

Please note that each zero-carb diet has its own specific food list, and you need to check the rules of the zero-carb diet you aim to try. The following list is a general guideline.

• Meat: Beef, pork, lamb, etc.
• Poultry: Chicken, turkey, duck, and other poultry.
• Fish: Salmon, trout, tuna, mackerel, and other fatty fish.
• Shellfish: Shrimp, crab, lobster, etc.
• Eggs: Both whole eggs and egg whites.
• Dairy: Some dairy products like butter and certain cheeses are very low in carbs. But milk and yogurt usually contain more carbohydrates.
• Fats and Oils: Olive oil, coconut oil, butter, lard, and other healthy fats.
• Non-starchy Vegetables: While most vegetables contain some carbs, certain leafy greens and cruciferous vegetables, like spinach, kale, broccoli, and cauliflower, have very low amounts.
• Herbs and Spices

The following table summarizes the carbohydrate, calorie, fat, protein, and sugar content in 100 grams of the above foods allowed on a zero-carb diet [26] [27] [28] [29] [30].

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By checking the above list, you can probably guess what you cannot consume on a zero-carb diet. But the list below summarizes what you need to avoid eating.

What Should I Avoid Eating on a Zero-Carb Diet?

Again, it’s important to check the specific zero-carb diet you aim to follow for the list of the foods allowed and excluded. Anyhow, you need to minimize or avoid carbohydrate intake altogether.

Cutting carbs can happen gradually or at once, based on your specific goals and needs. But please remember that the most important thing is improving your lifestyle and finding a healthier approach, not perfection.

Here are the general sources of carbohydrates you need to avoid on a typical zero-carb diet.

• Grains: Wheat, rice, barley, oats, quinoa, and other high-carb grains
• Legumes: Beans, lentils, chickpeas, etc.
• Starchy Vegetables: Potatoes, sweet potatoes, carrots, etc.
• Fruits: Most fruits are high in carbohydrates due to natural sugars, so you should avoid fruits on a zero-carb diet.
• Sugars and Sweeteners: Any form of sugar, honey, maple syrup, and artificial sweeteners are excluded.
• Processed Foods: Many processed foods contain hidden sugars and carbs, so it’s wise to avoid packaged snacks, desserts, and processed meats.
• Dairy with High Carbs: Milk and sweetened yogurts can be high in carbohydrates, so you can avoid dairy or choose lower-carb products like butter and certain cheeses.
• High-Carb Drinks: Instead of sugary drinks, fruit juices, and high-carb beverages, drink water, tea, and coffee without added sugars.

The following table shows the average carbohydrate, calorie, protein, fat, and fiber content in 100 grams of the above foods NOT allowed on a zero-carb diet. Checking the carbohydrate column, you can realize why they are not allowed [31] [32] [33] [34] [35].

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Also, to help you get started, I have provided a sample 3-day zero-carb meal plan, which you can modify based on your specific needs and preferences. Just ensure you use low- or zero-carb alternatives.

Sample 3-Day Zero-Carb Meal Plan

This sample 3-day zero-carb meal plan is to give you a general idea of the foods you can consume on a zero-carb diet. Surprisingly, the variety is high, and the allowed foods are quite yummy!

Day 1

Breakfast:

• Scrambled eggs cooked in butter
• Bacon or sausage

Lunch:

• Grilled chicken breast
• Spinach salad with olive oil dressing

Dinner:

• Salmon fillet baked with herbs and lemon
• Steamed broccoli with butter

Snacks:

• Hard-boiled eggs
• Cheese slices

Here is the approximate level of carbohydrates, calories, protein, fat, and sugar you receive from this plan.

• Carbohydrates: Very low
• Calories: Around1800 calories
• Protein: About 120 grams
• Fat: Near 130 grams
• Sugar: Almost none

Day 2

Breakfast:

• Omelet with cheese and diced ham
• Coffee or tea (unsweetened)

Lunch:

• Turkey or chicken lettuce wraps with mayo
• Celery sticks

Dinner:

• Beef steak cooked in olive oil
• Cauliflower rice sautéed with garlic

Snacks:

• Pork rinds
• Cucumber slices with cream cheese

The following list shows the approximate level of carbohydrates, calories, protein, fat, and sugar in this meal plan.

• Carbohydrates: Very low
• Calories: Around 1700 calories
• Protein: Roughly 110 grams
• Fat: About 120 grams
• Sugar: Almost none

Day 3

Breakfast:

• Smoked salmon and cream cheese roll-ups
• Black coffee or herbal tea

Lunch:

• Shrimp stir-fry with broccoli and bell peppers
• Avocado slices

Dinner:

• Grilled lamb chops with rosemary
• Zucchini noodles tossed in olive oil

Snacks:

• Hard cheese cubes
• Beef jerky (watch for added sugars)

The list below summarizes the approximate level of carbohydrates, calories, protein, fat, and sugar received from day three’s meal plan.

• Carbohydrates: Near zero
• Calories: About 1900 calories
• Protein: Near 130 grams
• Fat: About 140 grams
• Sugar: Almost zero

Learn More: Carnivore Diet Meal Plan: Your 30-Day Free Beginner Guide

Summary

Going on a zero-carb diet can have various health benefits if only you choose the proper zero-carb diet, and it aligns with your health status, body needs, and fitness goals.

To ensure any type of zero-carb diet can help you achieve your goals, you can consult a healthcare professional or registered dietitian and get a personalized tailor-made plan.