Low-carb and keto diets are two popular ways of eating that involve restricting your carb intake. While both diets limit carbs to a certain extent, the keto diet is more restrictive. For the majority of the population, the low-carb diet appears to be more sustainable in the long term.

On a low-carb diet, you typically eat 50–150 grams of carbs per day, but on the keto diet, daily carb intake is restricted to fewer than 50 grams. This puts your body in a state of nutritional ketosis, which promotes the use of fat as a primary fuel source.

The keto diet is a very low-carb, high-fat diet that has gained popularity in recent years. It has several therapeutic properties, such as helping treat epilepsy and impairing the growth of certain types of cancer. It may also help with weight loss and improving insulin sensitivity.

A low-carb diet is a way of eating that restricts dietary carbohydrates, mainly from grains, sugar-sweetened beverages, and bread. It has been linked to several health benefits, including weight loss, improved blood sugar control, and reduced cardiovascular risk factors.

The main difference between these diets is carbohydrate intake. The keto diet is more restrictive and may be too challenging for some people to follow. The low-carb diet is less extreme and easier to follow, making it a better option for most people.

Characteristics and Values of a Low-Carb or Keto Diet

What is a low-carb diet?

A low-carb diet is a way of eating that restricts dietary carbohydrates, mainly from grains, sugar-sweetened beverages, and bread. There is no strict definition of a low-carb diet, but anything under 100-150 grams of carbohydrates per day is generally considered low-carb. This is significantly less than the amount of carbs in a standard Western diet, which can be as high as 250 grams of carbs per day.

On a low-carb diet, it is common to increase your intake of protein, healthy fats, and vegetables to replace the carbs and promote fullness. By restricting carbs, you also eliminate many high-calorie foods from your diet, which can lead to reduced overall calorie intake and promote weight loss.

Low-carb diets have been linked to several health benefits, including weight loss, improved blood sugar control, and reduced cardiovascular risk factors. They are particularly effective for people with diabetes, as they can help lower blood sugar and improve insulin sensitivity.

Low-carb diets can be sustained long-term and are generally less restrictive and easier to follow than keto diets. However, some people may experience side effects such as weakness or constipation, and there may be an impact on micronutrient intake.

When deciding to start a low-carb diet, it is important to consider individual factors such as age, weight, physical activity, and medical history. It is also crucial to ensure that carbs are replaced with other quality foods, such as high-fiber carbs like vegetables, fruits, legumes, and whole grains.

Types of Low-Carb Diets

There are different types of low-carb diets, and the ideal carb intake can vary depending on individual factors. Here are some common types:

• Very low-carb ( <10% carbohydrates) or 20 to 50 grams per day: This is the most restrictive type of low-carb diet and is typically followed by people with a lot of weight to lose, type 2 diabetes, insulin resistance, or metabolic syndrome.
• Low-carb ( <26% carbohydrates) or less than 130 grams per day: This is a less restrictive option that may be suitable for those with less weight to lose or who have good blood sugar levels.
• Moderate-carb (26%-44%): This type of diet allows for a higher carb intake while still providing potential health benefits.
• High-carb (45% or greater): While this is not considered a low-carb diet, the Institute of Medicine proposes that Americans obtain 45% to 65% of their calories from carbohydrates.

Benefits of a Low-Carb Diet

A low-carb diet offers several potential benefits, including:

• Weight loss: Studies have shown that low-carb diets can reduce appetite, lead to a reduction in calorie intake, and promote weight loss.
• Improved blood sugar control: Low-carb diets can help lower blood sugar levels, making them particularly beneficial for people with diabetes.
• Reduced cardiovascular risk factors: Low-carb diets have been associated with improved cardiovascular risk factors, including reduced triglycerides and increased HDL cholesterol.
• Lower blood pressure: Research suggests that low-carb diets can help reduce blood pressure.

Considerations for a Low-Carb Diet

When considering a low-carb diet, it is important to keep the following in mind:

• Side effects: Some people may experience side effects such as weakness or constipation when following a low-carb diet.
• Micronutrient intake: Restricting carbs may impact micronutrient intake, so it is important to ensure adequate nutrient intake from other food sources.
• Individual factors: The ideal carb intake varies depending on age, sex, body composition, activity levels, and current metabolic health. It is important to consider these factors when determining the appropriate carb intake for your low-carb diet.
• Food choices: A low-carb diet should be based on whole, unprocessed foods and healthy carb sources. Low-carb junk foods are often unhealthy and may not provide the intended benefits.

What is a keto diet?

The keto diet is a very low-carb, high-fat diet that has gained popularity in recent years. It is a therapeutic diet with several health benefits, such as managing epilepsy and potentially impairing the growth of certain types of cancer. It is also used for weight loss.

On a keto diet, the body is put into a state of nutritional ketosis, where it uses fat as its main fuel source instead of carbohydrates. This is achieved by consuming fewer than 50 grams of carbohydrates per day, while keeping protein intake moderate and increasing fat intake drastically.

Who is it for?

The keto diet is restrictive and may not be a practical long-term option for those looking to lose weight and improve their health. It may be too restrictive for most people, leading to poor long-term adherence. It is also more likely to cause unwanted side effects such as constipation, the keto flu, and headaches.

However, it can be a good option for people with a lot of weight to lose, type 2 diabetes, insulin resistance, metabolic syndrome, or sugar and/or food addiction. These individuals tend to see better results on a keto diet, keeping carbs very low.

The main difference between a keto and a low-carb diet is the amount of carbohydrate intake. A keto diet restricts daily carb intake to fewer than 50 grams, while a low-carb diet typically allows for 50-150 grams of carbs per day.

Another difference is protein intake. Protein intake may be high on a low-carb diet, but with keto diets, protein intake should be moderate at around 20% of total calories. This is because excessive protein intake can prevent ketosis.

Additionally, fat intake tends to be significantly higher on a keto diet, as fats replace carbs and protein.

A keto diet is based on whole, unprocessed foods and healthy carb sources. It includes foods such as:

• Eggs
• Dairy products
• Fresh meat and fish
• Cheese
• Dark green vegetables (e.g. broccoli)

Research has found that the average weight loss within 12 months on a keto diet tends to be about 13 pounds (lb) or 6 kilograms (kg).

Another study found that participants on a keto diet for 8 weeks lost 22.8% of their visceral fat, compared to 1% for those on a low-fat diet.

How to calculate net carbs

The term "net carbs" is disputed among nutrition experts and is not recognised by the Food and Drug Administration (FDA). However, net carbs are generally understood to refer to the total amount of digestible carbohydrates in a food product or meal. Net carbs are calculated by subtracting indigestible carbohydrates, such as fibre and some sugar alcohols, from the total amount of carbohydrates.

To calculate net carbs in whole foods, you subtract the fibre content from the total number of carbs. For example, if a medium avocado contains 17.1 grams of total carbs, 13.5 grams of which is fibre, then the net carbs are 3.6 grams (17.1 grams of total carbs – 13.5 grams of fibre = 3.6 grams of net carbs).

Calculating net carbs in processed foods is a little more complicated. Generally, half of the carbs from sugar alcohols can be subtracted from the total carbs listed on the nutrition label. However, erythritol, a sugar alcohol that is not digested by the body, can be completely subtracted from the total carbs. For example, a maltitol-sweetened Atkins bar may state on its label that it contains 3 grams of net carbs. However, when subtracting only half the carbs from sugar alcohols, the net carb value is 8.5 grams (23 grams of total carbs – 9 grams of fibre – 11 grams sugar alcohols (11 grams x 0.5 = 5.5 grams) = 8.5 grams of net carbs).

For people with diabetes, calculating net carbs can be a helpful way to track their intake of dietary fibre and balance medications with carb intake. However, it is important for people with diabetes to consult a doctor, dietitian, or diabetes educator before starting a low-carb diet.

Pros and cons of low-carb and keto diets

Low-Carb Diets

Low-carb diets are a popular strategy for weight loss. They involve reducing the intake of carbohydrates, mainly from grains, sugar-sweetened beverages, and bread. While there is no set definition, studies suggest that a low-carb diet comprises 10–30% of calories from carbs, which equates to 50–150 grams of carbs per day for a healthy person consuming 2,000 calories.

Pros

• May promote weight loss
• Eliminates many processed high-carb foods
• Can be sustained long-term
• Less extreme adaptation phase than keto
• Less restrictive and easier to follow than keto

Cons

• May cause weakness or constipation
• May impact micronutrient intake

Keto Diets

The keto diet is a very low-carb, high-fat diet that has gained popularity in recent years. It has several therapeutic properties, such as treating refractory epilepsy and potentially impairing the growth of certain types of cancer. The goal is to reach nutritional ketosis, where the body produces ketones from fat in the liver and uses fat as its main fuel source instead of carbs. This is achieved by consuming fewer than 50 grams of carbs per day, keeping protein intake moderate, and increasing fat intake drastically.

Pros

• Has therapeutic benefits, such as managing epilepsy
• May improve insulin sensitivity
• May reduce appetite
• Can improve cholesterol and triglyceride levels

Cons

• Constipation is common due to low fiber intake
• Long-term data is limited
• Risk of the keto flu, which may include headaches, fatigue, brain fog, irritability, and lack of motivation
• May be difficult to stick to for long periods
• Can cause nutrient deficiencies
• May cause digestive issues
• Could be bad for heart health

Comparison

When choosing between low-carb and keto diets, the main factors to consider are carbohydrate and protein intake. Low-carb diets typically allow for 50–150 grams of carbs per day, while keto diets restrict daily carb intake to fewer than 50 grams. Low-carb diets may have higher protein intake, while keto diets should keep protein intake moderate at around 20% of total calories to prevent interference with ketosis. Fat intake tends to be significantly higher on the keto diet, as fats replace carbs and protein.

The keto diet may be too restrictive for most people, leading to poor long-term adherence. It is also more likely to cause unwanted side effects. Therefore, a low-carb diet is likely a better option for most individuals. However, it is important to consult a healthcare provider before starting any diet to reduce the risk of complications.

How to choose the right carb level for your goals

The right carb level for your goals depends on several factors, including your age, sex, body type, and activity level. Here are some guidelines to help you choose the right carb level:

Determine Your Goals

Before choosing a carb level, it's important to define your goals. Are you aiming for weight loss, improved health, or better management of a medical condition such as diabetes? Different carb levels may be more or less effective for different goals.

Understand the Basics of Low-Carb and Keto Diets

Low-carb and keto diets are both effective approaches for weight loss and improving health. A low-carb diet typically restricts carbohydrates to 10-30% of total calorie intake, while a keto diet is more restrictive, limiting carbs to less than 50 grams per day.

Assess Your Individual Factors

As mentioned earlier, your age, sex, body type, and activity level play a role in determining the right carb level. For example, if you're more active, you may be able to tolerate a higher carb intake without compromising your goals.

Start With a Trial Period

Consider starting with a trial period, such as a two-week keto diet, to see how your body responds. This will give you an idea of whether you feel better and see results. If you find it challenging to stick to a very low-carb diet, you may want to opt for a more moderate approach.

Monitor Your Progress and Make Adjustments

Regularly assess your progress towards your goals. If you're not seeing the desired results, consider adjusting your carb intake up or down. Remember that everyone's body is unique, and you may need to experiment to find the right carb level for you.

Consult a Healthcare Professional

Before making any significant dietary changes, it's always a good idea to consult a healthcare professional. They can provide personalized advice based on your health status, goals, and preferences. Additionally, they can help monitor your progress and make adjustments as needed.

Frequently asked questions