The keto diet limits carbohydrates and replaces them with fats. This puts the body into a state of ketosis. A person should consume up to 50 grams (g) of carbs per day on the keto diet to stay in ketosis.

A person on a keto diet eats foods that contain high levels of fats and very low levels of carbohydrates. The diet excludes a wide range of foods, including some fruits and vegetables, as well as bread, beans, and legumes.

This article looks into the number of carbs that the keto diet allows per day and which foods can help a person stay on track.

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According to a 2018 review of the different types of ketogenic diet, a person should consume up to 50 grams (g) of carbohydrates per day to stay in ketosis.

A female on a keto diet should consume 40–50 g of protein per day, while a male should consume 50–60 g of protein daily.

But different keto diets allow for different amounts of carbs, protein, and fat:

  • Standard ketogenic diet: Overall, 70% of a person’s intake is fat, 20% is protein, and 10% is carbs.
  • Cyclical ketogenic diet: There is a cycle of 5 low carb days and 2 high carb days.
  • Targeted ketogenic diet: A person can eat more carbs around high intensity workouts.
  • High protein ketogenic diet: Overall, 60% of a person’s intake is fat, 35% is protein, and 5% is carbs.

The standard keto diet has been the subject of most research, and experts who recommend ketogenic diets tend to be more likely to recommend this type.

Learn about benefits of the keto diet here.

For anyone on the keto diet, it is important to consider the number of “net carbs” in foods.

A person can calculate the number of net carbs in a serving by subtracting the amount of fiber from the total number of carbs. If the food is processed, a person should also subtract half the sugar alcohol content. These quantities are included on food labels.

We look into these terms and the calculation in more depth below:

Total carbs

These are all the carbs in a serving of food, including the type that the body cannot completely digest and transfer into glucose for energy.

Net carbs

The body is able to absorb these, and they are also called digestible carbs.

To calculate the number of net carbs in a serving, subtract the fiber content from the number of total carbs. If the food is processed, also subtract half the sugar alcohol content.

Learn more about calculating net carb values here.

Fiber

Fiber is a type of carbohydrate that the body cannot digest and so cannot transform into glucose to store and use for energy.

The amount of fiber is included in the number of total carbs, but not in the number of net carbs.

Sugar alcohol

To calculate the number of net carbohydrates in processed foods, a person also needs to subtract half the amount of sugar alcohol from the number of total carbs.

The body does not digest all sugar alcohols, so these have less of an effect on blood sugar levels than regular sugar does.

Some examples of sugar alcohols include:

  • sorbitol
  • xylitol
  • mannitol
  • isomalt
  • maltitol
  • lactitol
  • hydrogenated starch hydrolysates

Find out more about sugar alcohols.

When a person consumes carbohydrates, the body turns those carbs into sugar, which cells use for energy.

Significantly limiting the intake of carbs causes the body to burn fat instead of carbs for energy. As a result, glucose levels drop.

This forces the body to produce ketones, acids that appear in the blood and urine when the body burns fat. When the body uses fat as energy and releases ketones, this is called ketosis.

During ketosis, the body also produces less insulin, and it stores less fat as a result.

Learn more about how ketosis works.

The keto diet may help support weight loss, if this is a goal, by reducing levels of hunger and boosting metabolism. It may also help manage type 2 diabetes because the diet can reduce glucose levels.

How can someone with type 2 diabetes follow the keto diet safely?

Below, we explore how many net carbs various foods contain. This measurement excludes fiber and half the amount of sugar alcohols from the total number of carbs in the serving.

Fresh meat and fish

These foods tend to make up a large part of a keto diet, as they contain no carbohydrates but can be good sources of some nutrients.

Some examples of fresh meat and fish included in the keto diet include:

Learn how to incorporate meat into a diet for people with diabetes.

Dairy

FoodNet carbs per 100 g
eggs0.76 g
cheddar cheese2.44 g
Greek yogurt3.98 g

Cheese tends to be low in carbs but high in fat, making it a good choice for keto diets. For example, 100 g of cheddar cheese has 2.44 g of carbs and 34 g of fat.

Vegetables

Dark green vegetables, such as broccoli, are low in carbs and rich in magnesium, protein, vitamin C, and antioxidants.

Fruits

Fruits are a key part of any diet, as they are rich in vitamins and minerals.

However, some fruits are high in carbs, so doing research, including checking labels, is key.

Nuts and seeds

Here, learn more about foods for a ketogenic diet.

Wheat-based products, such as rice, pasta, and cereals, are high in carbs. Therefore, a person on a keto diet should avoid them.

Below, we look at how many net carbs are in 100 g of various other foods.

Vegetables

FoodNet carbs per 100 g
potato16.17 g
parsnip13.09 g
beet6.76
corn16.70 g
carrot6.78 g

Fruits

Nuts, beans, and legumes

FoodNet carbs per 100 g
cashews24.97 g
chickpeas16.80 g
kidney beans10.75 g
lentils52.65 g

Keeping the keto diet sustainable can be challenging because it is very restrictive. A person may become bored by what they can eat.

Moreover, the diet can cause side effects.

Learn about possible side effects of the ketogenic diet here.

Gradual changes

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.

Whole, unprocessed foods

Aim to consume carbs from whole, unprocessed foods to benefit from their vitamins and minerals.

Monitoring

For people on 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 hypoglycemia, or low blood sugar.

Overall, it is important to check with a doctor before making any significant changes to the diet, such as by switching to a ketogenic diet.

A person on the keto diet should limit their carb intake to up to 50 g a day. A person generally replaces high carb foods with fatty foods, such as eggs, dairy products, and fresh meat and fish.

Wheat products and some fruits, vegetables, beans, and legumes can be high in carbs, so checking food labels is key.

Before starting a keto diet, contact a doctor to make sure that the change will be safe.