Zero Carb Intake: Ideal For Keto Diet?

The keto diet is a low-carb, high-fat diet that can be effective for weight loss and certain health conditions. While there is no strict definition of a low-carb diet, anything under 100-150 grams of carbs per day is generally considered low-carb. To get into ketosis, which is essential for a ketogenic diet, most people will need to go under 50 grams of carbs per day.

The keto diet involves significantly limiting carb intake, which causes the body to burn fat instead of carbs for energy, leading to a drop in glucose levels and the production of ketones by the liver. This state is called ketosis.

The standard keto diet consists of 70% fat, 20% protein, and 10% carbs. However, different keto diets allow for different amounts of carbs, protein, and fat.

While the keto diet can be effective for weight loss and managing type 2 diabetes, it also has several risks. It is high in saturated fat, which has been linked to heart disease. It may also lead to nutrient deficiencies, liver problems, kidney problems, constipation, and fuzzy thinking.

Therefore, it is important to consult a doctor and a registered dietitian before attempting a ketogenic diet.

How to calculate net carbs

Net carbs refer to the amount of carbohydrates that your body can fully digest and absorb. To calculate the net carbs in a food product, you subtract the amount of fibre and sugar alcohols from the total number of carbohydrates.

Here's a step-by-step guide on how to calculate net carbs:

• Check the Nutrition Label: Start by looking at the nutrition facts panel on the food package. Identify the total number of carbohydrates per serving. Note that the serving size is typically provided in grams (g) or millilitres (ml).
• Identify the Fibre Content: Find the amount of dietary fibre listed on the nutrition label. The fibre content may be listed underneath the total carbohydrate section or in a separate section.
• Subtract Fibre from Total Carbohydrates: To calculate net carbs, subtract the grams of fibre from the total grams of carbohydrates. This gives you the number of net carbs that your body can digest.
• Consider Sugar Alcohols (for Processed Foods): If you're calculating net carbs for a processed or packaged food item, you may also need to consider sugar alcohols. Sugar alcohols are used as sweeteners in many low-carb foods. They are only partially digested and have a lesser impact on blood sugar levels compared to regular sugar.
• Subtract Half the Sugar Alcohols: To account for sugar alcohols, subtract half of their total grams from the total carbohydrates. For example, if a food product has 10 grams of sugar alcohols, subtract 5 grams from the total carbohydrates.
• Erythritol Exception: One type of sugar alcohol, erythritol, is not digested by the body and has a negligible impact on blood sugar. If erythritol is the only sugar alcohol listed in the ingredients, you can subtract its full amount from the total carbohydrates.
• Final Calculation: After making the necessary subtractions, you will be left with the net carb value. This represents the amount of carbohydrates your body can digest and absorb.

For example, let's say you're calculating net carbs for a food product with 25 grams of total carbohydrates, 5 grams of dietary fibre, and 10 grams of sugar alcohols.

• First, subtract the fibre: 25 grams (total carbs) - 5 grams (fibre) = 20 grams.
• Then, subtract half the sugar alcohols: 20 grams - 5 grams (half of sugar alcohols) = 15 grams of net carbs.

It's important to note that the calculation of net carbs can vary depending on the specific food and its ingredients. Additionally, nutritional labels may differ, so always read the label carefully.

Calculating net carbs can be especially useful for people following a ketogenic diet, as it helps them monitor their carbohydrate intake to stay within the recommended range for ketosis.

What foods are low in net carbs?

Net carbs are the amount of carbohydrates your body actually absorbs. To calculate net carbs, subtract the fibre content from the total number of carbs. For processed foods, also subtract half of the sugar alcohol content.

Animal proteins

Animal protein has close to zero carbs. Organ meats, such as raw beef liver, are an exception. Examples of animal protein include:

• Red meat, such as beef, pork and lamb
• Poultry, such as chicken and turkey
• Fish, such as salmon, tuna, sole, trout, and halibut

Vegetables

Most vegetables are low in carbs. Leafy greens and cruciferous vegetables have particularly low levels, and most of their carbs consist of fibre. The following vegetables have about 3–9 grams of carbs per 100 g in their raw, unprocessed forms:

• Broccoli
• Cauliflower
• Tomatoes
• Eggplant

Fruits

Depending on how many carbs you aim for, you may want to restrict your fruit intake to 1–2 pieces per day. However, this does not apply to fatty fruits like avocados or olives. Low-sugar berries, such as strawberries, are another excellent choice. The following fruits have about 6–15 g of carbs per 100 g in their raw forms:

• Apricots
• Avocados

Nuts and seeds

Nuts and seeds are very popular on low-carb diets. Some are low in carbs but high in fat, fibre, protein, and various micronutrients. Examples include:

• Pumpkin and squash seeds
• Chia seeds

Dairy

If you tolerate dairy, full-fat dairy products are excellent low-carb foods. Examples include:

• Full-fat yoghurt
• Cheese

Fats and oils

Fats and oils do not contain any carbs and are acceptable on a low-carb, real-food-based diet. Examples include:

Extra virgin olive oil

Beverages

The safest beverages to drink are water, coffee, and tea because they contain no carbs. You can also drink carbonated water if it’s sugar-free.

Other foods

Some foods that don't quite fit into any other category include:

• Dark chocolate
• Herbs, spices, and condiments

Tips for the keto diet

• Keeping the keto diet sustainable can be challenging because it is very restrictive. A person may become bored by what they can eat.
• It can help to ease into the diet gradually. For instance, a person might stop eating one type of food at a time, such as bread or juice that is high in carbs and sugar.
• Aim to consume carbs from whole, unprocessed foods to benefit from their vitamins and minerals.
• For people following the keto diet, regular health monitoring is important to check whether the diet is having any effects on the heart.
• For people with diabetes, it is also important to monitor for hypoglycaemia (low blood sugar).

How to get into ketosis

To get into ketosis, you need to reduce your carbohydrate intake to a minimum and replace those calories with fat and moderate protein. The body will then start burning fat for fuel instead of carbohydrates, which is the essence of the keto diet.

Reducing Carbohydrates

According to a 2018 review, a person should consume no more than 50 grams of carbohydrates per day to stay in ketosis. This number may vary slightly between individuals, but it is generally recommended to stay under 50 grams.

To calculate your carb intake, it is important to consider the number of "net carbs" in foods. Net carbs are calculated by subtracting the amount of fibre from the total number of carbs. If the food is processed, you should also subtract half of the sugar alcohol content.

Wheat-based products such as rice, pasta, and cereals are high in carbs and should be limited. Other high-carb foods include some fruits, starchy vegetables, beans, and legumes.

Increasing Fat and Moderate Protein Intake

The keto diet is a high-fat diet, with fat supplying up to 90% of daily calories. Healthy unsaturated fats such as nuts, seeds, avocados, tofu, and olive oil are allowed, but saturated fats from oils, lard, butter, and cocoa butter are encouraged in high amounts.

Protein is also part of the keto diet, but it is important not to overdo it as excessive protein intake can interfere with ketosis. The recommended intake for protein is around 46-56 grams per day.

Tips for Sticking to the Keto Diet

The keto diet can be challenging due to its restrictive nature. Here are some tips to help you stick to the diet:

• Ease into the diet gradually by eliminating one type of high-carb food at a time.
• Focus on consuming carbs from whole, unprocessed foods to benefit from their vitamins and minerals.
• Regularly monitor your health to check for any potential side effects of the diet, especially on the heart and kidney function.
• Consult a doctor or dietitian before making any significant changes to your diet.

Potential Risks of the Keto Diet

The keto diet has numerous potential risks, including:

• High saturated fat content, which has been linked to heart disease.
• Nutrient deficiencies, especially if a wide variety of vegetables, fruits, and grains are not consumed.
• Liver problems due to the high amount of fat that needs to be metabolized.
• Kidney problems as a result of high protein intake.
• Constipation due to the low intake of fibrous foods.
• Fuzzy thinking and mood swings as the brain functions best when using sugar from carbohydrates as an energy source.

It is crucial to consult a doctor and a registered dietitian before attempting the keto diet to ensure it is safe for your individual needs and health status.

Potential risks of a keto diet

A ketogenic diet is generally safe, but there are some potential risks and side effects to be aware of. It is always recommended to consult a doctor or dietitian before starting a new diet. Here are some potential risks of a keto diet:

• Nutrient deficiencies: The keto diet restricts several food groups, including fruits, whole grains, and legumes, which are excellent sources of essential vitamins and minerals. Some studies suggest that the keto diet may not provide enough calcium, vitamin D, magnesium, phosphorus, and vitamins B and C. Over time, this could lead to nutrient deficiencies.
• Digestive issues and changes in gut bacteria: The keto diet restricts carbohydrates, making it challenging to meet daily fiber needs. Fiber is essential for digestive health and feeding beneficial gut bacteria. The keto diet's lack of fiber can lead to constipation and other digestive issues.
• Kidney problems: The high protein and animal food content of the keto diet may increase the risk of kidney stones. Additionally, the diet may overload the kidneys, which are responsible for metabolizing protein. People with chronic kidney disease should avoid keto as it can worsen their condition.
• Liver problems: The keto diet's high-fat content means the liver has to metabolize a large amount of fat. This could worsen existing liver conditions.
• Constipation: The keto diet is low in fibrous foods like grains and legumes, which can lead to constipation.
• Fuzzy thinking and mood swings: The brain typically functions best when using glucose from carbohydrates as its primary energy source. Low-carb diets like keto may cause confusion and irritability due to the reduced availability of glucose.
• Increased risk of chronic diseases and early death: There is ongoing debate about the long-term effects of the keto diet on chronic illnesses such as heart disease and cancer. Some evidence suggests that keto diets high in animal fats may lead to poor health outcomes, while those emphasizing vegetable sources of fats and proteins offer benefits. More research is needed to fully understand the potential risks.

Tips for the keto diet

The keto diet is a low-carb, high-fat diet that can be effective for weight loss and certain health conditions. Here are some tips to help you get started and stay on track:

• Understand the basics: The keto diet aims to force your body to use a different type of fuel by reducing carbohydrate intake and increasing fat intake. This shift in fuel sources causes the body to produce ketones, which are used for energy instead of glucose.
• Limit your carb intake: To stay in ketosis, limit your carbohydrate intake to up to 50 grams per day. This may vary slightly depending on the individual, but it is generally recommended to keep net carbs below 50 grams per day.
• Choose the right foods: Focus on high-fat, low-carb foods such as meat, poultry, fish, eggs, and other protein-rich foods. Include leafy greens and non-starchy vegetables. Use healthy fats like olive oil for flavor and fullness. Avoid sugary and starchy foods, wheat products, and high-carb fruits, vegetables, beans, and legumes.
• Calculate net carbs: When tracking your carb intake, focus on "net carbs" rather than total carbs. Net carbs are absorbed into the body and include digestible carbohydrates. To calculate net carbs, subtract the amount of dietary fiber and half the amount of sugar alcohols from the total carbohydrate amount.
• Ease into the diet gradually: The keto diet is very restrictive, so it can be helpful to transition slowly. Try eliminating one type of high-carb food at a time, such as bread or sugary juice.
• Focus on whole, unprocessed foods: Choose carbs from whole, unprocessed food sources to ensure you're getting essential vitamins and minerals.
• Monitor your health: Regular health check-ins are important to ensure the keto diet is not negatively affecting your heart or causing other health issues. For people with diabetes, it is crucial to monitor for hypoglycemia (low blood sugar).
• Consult a healthcare professional: Before starting the keto diet or making any significant dietary changes, consult a doctor or dietitian to ensure it is safe and appropriate for your individual needs.

Frequently asked questions