Type 2 diabetes is a condition that impacts blood sugar control. A ketogenic, or keto diet, is a high fat, moderate protein, and very low-carbohydrate diet that may help some people manage their blood sugar.

Some have suggested that the keto diet might help an individual with type 2 diabetes, but the American Diabetes Association (ADA) does not recommend one diet over another.

Everyone has different dietary needs. Healthcare professionals and registered dietitians now individualize diet plans based on a person’s eating habits, preferences, and target weight and blood sugar levels.

In this article, we look at if the keto diet works for the management of type 2 diabetes.

Top-down view of a bowl of salad leaves, feta, and tomatosShare on Pinterest
Cavan Images/Getty Images

Limiting the intake of carbohydrates is the central concept of the keto diet.

The idea is to limit carbohydrate-rich foods that could raise a person’s insulin levels. Typically, the carbohydrate intake on a keto diet ranges from 20–50 grams (g) per day for a 2,000-calorie diet.

To follow the keto diet, people might consider developing a diet plan with 10% of their calories from carbohydrates, 20% from protein, and 70% from fat. However, there are different versions of the diet, and macronutrient proportions vary depending on the type.

A keto diet may consist of the following types of food:

  • Low carb vegetables: These include leafy greens and broccoli.
  • Eggs: Eggs are low in carbohydrates, as well as an excellent source of protein.
  • Meats: The keto diet allows for poultry, beef, and pork, as they are rich in high-quality protein.
  • Healthful fat sources: These include avocados, olive oil, nuts, and seeds.
  • Fish and shellfish: These are sources of protein.
  • Dairy: Unsweetened dairy products are acceptable in a keto diet.
  • Berries: These are sources of fiber, vitamins, minerals, and antioxidants that are okay to consume on the keto diet in the right quantity.

Researchers initially developed and continue to recommend the keto diet for children with epilepsy. However, some recent reviews maintain that it might benefit some people with diabetes.

The keto diet severely restricts carbohydrates, forcing the body to break down fats for energy. Ketosis is the process of using fat for energy. It produces a fuel source called ketones.

Foods containing carbohydrates, such as bread, rice, pasta, milk, and fruit, are the main fuel for many bodily processes. The body uses insulin to help bring glucose, also known as blood sugar, from the blood into the cells for energy.

However, for people with diabetes, insulin is either absent or does not work properly. This disrupts the ability of the body to use carbohydrates effectively, and in turn, causes sugar levels to be high in the blood.

Eating a high carb meal could lead to a rise in blood sugar, especially in someone with diabetes. Diet is important for both type 1 and type 2 diabetes.

Scientists have looked into the main motivations that people with type 2 diabetes have for starting a keto diet. They include:

  • improving blood sugar control
  • stopping or reducing diabetes medications
  • losing weight
  • reversing diabetes

Does keto work for managing type 2 diabetes?

A keto diet could help some people with type 2 diabetes because it allows the body to maintain blood sugar levels at a low but healthy level.

The diet’s lower intake of carbohydrates may help minimize large fluctuations in blood sugar, which could better impact several clinical markers of blood sugar control.

However, a 2022 review of randomized clinical trials found little evidence to support keto diets for the long-term management of type 2 diabetes.

Researchers noted that while some studies show that low carb diets could improve glycemic control and aid weight loss, studies typically only lasted 6–12 months. Overall, dropout rates in the keto diet groups were as high as 54%.

HbA1c is a clinical measure of blood sugar control that tests the amount of blood sugar traveling with hemoglobin in the blood over about 3 months and is an important component of type 2 diabetes management.

However, a study in The American Journal of Clinical Nutrition compares following a keto diet to a Mediterranean diet in 33 people with type 2 diabetes for 12 months. The study’s authors found that HbA1c values did not differ between the diets, despite both diets improving HbA1c values throughout the study.

These conflicting studies are why experts caution against suggesting there is a keto diet advantage for type 2 diabetes over other common dietary strategies, especially over a longer term.

Scientists continue to study the impacts of a keto diet on people with type 2 diabetes, including the underlying mechanisms that may explain the observed benefits.

There are some groups of people who should not follow a keto diet, including people:

  • pregnant or lactating
  • with a history of or current diagnosis of an eating disorder
  • with kidney disease
  • taking certain medications, such as SGLT-2 inhibitors
  • with pancreatitis
  • with liver failure
  • with disorders of fat metabolism

Benefits

The keto diet could lead to a variety of other benefits, including:

  • weight loss
  • a reduced dependency on anti-diabetic medication
  • lower blood pressure
  • an improved insulin sensitivity
  • improvements in high-density lipoprotein (HDL) cholesterol, without increasing low-density lipoprotein (LDL) cholesterol
  • improvements in triglycerides
  • improved quality of life
  • improved feelings of fullness

Impact on medication

As keto diets could help reduce blood sugar levels and weight, people with type 2 diabetes, who follow a keto diet, may be able to reduce their need to take anti-diabetic medication.

A study published in Nutrition Reviews found that people with type 2 diabetes who followed a keto diet had reduced their need to take anti-diabetic medication compared to other diet treatments, but only until 12 months.

People may find the keto diet hard to maintain long term. As people add carbohydrates back to their diet, they will need to increase their diabetes medication in turn.

However, experts warn that those following the keto diet alongside an insulin regimen might have a higher risk of developing low blood sugar, or hypoglycemia.

Hypoglycemia occurs when blood sugar levels fall below 70 milligrams per deciliter (mg/dl).

Consult with a healthcare professional about proper medication adjustments before starting a keto diet.

Impact on weight

The keto diet helps the body burn fat. This is beneficial when trying to reach or maintain a moderate weight. It may be helpful for people whose excess weight has influenced the development of prediabetes and type 2 diabetes.

Even light-to-moderate weight loss through diet and exercise might support glycemic control, overall well-being, and better energy distribution throughout the day in people who have type 2 diabetes,

Recent studies show that people with type 2 diabetes and obesity undertaking a keto diet have better weight loss than other diet strategies for up to 6 months.

Other reviews suggest that following a keto diet may reduce waist circumference among people with type 2 diabetes.

However, the restrictive nature of the keto diet can make it difficult to follow for a long time. People will typically find it more beneficial to follow a moderate diet and lifestyle program that is sustainable long term.

Is keto safe for people with type 2 diabetes?

The keto diet may be one possible blood sugar management option for some people with type 2 diabetes.

As the keto diet involves a shift in typical eating habits and the body switching to a different energy source, it might lead to some adverse effects.

Short-term side effects

Following the keto diet could result in short-term side effects, including:

In most instances, the side effects are temporary and could last a few days to a few weeks.

Long-term side effects

Long-term effects might include the development of kidney stones and an increased risk of nutrient deficiencies due to the restriction or exclusion of certain food groups while following a keto diet.

Other complications might include:

Some researchers have suggested that since a keto diet often involves additional fat, there might be a higher risk of cardiovascular disease (CVD) due to a buildup of fats in the arteries.

People with diabetes already have an increased risk of CVD. However, the scientific evidence is conflicting on the risk of CVD in people with type 2 diabetes following a keto diet.

There is a lack of evidence about the long-term safety and effectiveness of the keto diet, and healthcare professionals have called for more primary studies and evidence before recommending this diet for type 2 diabetes.

Ketosis is the desired state of the body using fat instead of carbohydrates for fuel when nutritionally altering the diet as part of the keto diet. In ketosis, the liver has broken down enough fat to produce ketones that circulate freely in the bloodstream.

Ketosis is a metabolic process that doctors generally consider safe for most people if managed properly. Ketosis is not a medical condition.

Ketoacidosis is a potentially life threatening medical complication. The body essentially believes it is starving and rapidly breaks down fat into ketones. When ketones become dangerously high, the blood can become more acidic.

Ketoacidosis is a complication of type 1 diabetes, but it can also occur in people with uncontrolled diabetes and people with alcoholism.

Some isolated reports of ketoacidosis occur when people with type 2 diabetes follow a keto diet with prolonged periods of fasting.

If symptoms of ketoacidosis appear, seek medical attention immediately.

The main problem with the keto diet is that it can be hard to follow in the long term because it is highly restrictive. Experts do not recommend following this diet for longer than 12 months.

When it comes to managing diabetes, there is no one right diet. The key is following an eating plan that meets personal preferences and needs and keeps clinical health targets, such as blood sugar levels or weight, in check.

To assess the benefits of the keto diet for type 2 diabetes, scientists suggest that benefits need to be present over a 12-month or greater period.

That is why additional long-term studies in larger samples of more diverse research participants are necessary.

A person may wish to seek medical supervision while following this diet. A person should always try to talk with a doctor or dietitian before making significant changes to their diet, including when trying a keto diet.

Health authorities in the United States do not recommend the keto diet to manage type 2 diabetes.

It may be better for people with type 2 diabetes to focus on:

  • following a healthful, balanced diet with plenty of fresh fruits and vegetables
  • spreading the intake of carbohydrates out evenly throughout the day
  • eating smaller meals more often rather than a large meal once a day

A healthcare professional can help individuals with type 2 diabetes choose the plan that best fits their lifestyle.

Discover more resources for living with type 2 diabetes by downloading the free T2D Healthline app. It provides access to expert content on type 2 diabetes and peer support through one-on-one conversations and live group discussions. Download the app for iPhone or Android.

Read this article in Spanish.