ketogenic diet diabetes

Fact-checked by Dr. Anthony Gustin, DC, MS.

Written by Lorenz Mac


Diabetes is one of the most common metabolic diseases in the country. In 2015, 30.3 million Americans (9.4% of the whole population) had diabetes and 1.5 million Americans are diagnosed with diabetes every year[*].

These overwhelming statistics show that diabetes is a disease that must be addressed.

Doctors from around the world can all agree that a healthy overall diet and consistent exercise regimen are the most effective natural solutions to prevent diabetes.

But in the nutrition world, there is a lot of confusion as to which specific diet is best.

Luckily, there is an overwhelming amount of research suggesting a low carbohydrate, high fat ketogenic diet may help ease symptoms of diabetes or, in some cases, eliminate it completely.

In this article, we’ll discuss the following:

What is Diabetes?

Before diving into the role of the ketogenic diet in diabetes, it’s important to understand how diabetes works and review some basic medical terms.

Diabetes is a disease that can occur when your blood sugar is chronically too high[*].

Blood sugar (or blood glucose) is your body’s main source of energy and comes from the food you eat — primarily carbohydrates.

Insulin is a hormone produced by your pancreas. When you eat, glucose enters the bloodstream and insulin helps transport this blood glucose into your cells to be used for energy.

When your body doesn’t make enough insulin, or doesn’t use it properly, sugar (or glucose) will remain in your bloodstream and won’t reach your cells. Over time, you will build up excessive amounts of sugar in your bloodstream and develop diabetes.

There are two main kinds of diabetes — type 1 diabetes and type 2 diabetes.

Type 1 diabetes occurs when your immune system destroys the beta cells in your pancreas responsible for producing insulin. This happens due to a combination of genetic and environmental factors. As a result, you are unable to produce insulin naturally. People with type 1 diabetes must take insulin everyday. Despite sometimes being referred to as juvenile diabetes, you can develop type 1 diabetes at any age. It accounts for just 5% of all diabetes cases in the United States[*].

Type 2 diabetes is the most common form of diabetes, accounting for 95% of all diabetes cases in the United States[*]. With type 2 diabetes, the pancreas usually produces some insulin, but either it’s not enough to meet your body’s needs or your cells have become resistant to it as a result of poor diet and lifestyle choices. You can develop type 2 diabetes at any age, but it occurs the most in middle aged and older adults[*].

The Ketogenic Diet and Type 2 Diabetes

In general, a ketogenic diet is safe to try if you have type 2 diabetes. More on other forms of diabetes later, which are a bit more complicated.  

With type 2 diabetes, your body doesn’t respond to insulin correctly — also known as insulin resistance. When you’re insulin resistant, sugar does not get deposited into your cells for energy. Instead, the sugar will build up in the blood — causing chronically high blood sugar — and your body is unable to use it.

Many people decide to follow a strict ketogenic diet to help prevent or reverse type 2 diabetes. This is because of the keto diet’s specific macronutrient breakdown, including a low carbohydrate intake.

Getting into ketosis means you need to restrict your carbs to 30 grams a day and up your fat intake. With such low carbohydrate intake, your body will naturally have lower blood sugar levels and require less insulin to move that sugar into your cells.

The ketogenic diet also has powerful fat burning effects and can be a highly effective tool in losing weight, which is crucial for diabetes prevention and diabetes management.

Many diabetics use this way of eating because they benefit from weight loss and improved insulin sensitivity.

Can the Ketogenic Diet Ever Cause Diabetes?

There is some confusion as to whether the ketogenic diet causes diabetes. This is because people mix up the terms ketosis with ketoacidosis.

These are two completely different states in the body — one of them providing benefits while the other could be fatal.

When you change your main source of energy from carbs to fats, you increase the ketones present in your blood. This is considered “nutritional ketosis” and is completely different from ketoacidosis.

Ketosis is the state in which your body is producing a healthy amount of ketones ranging from 0.1 mmol/liter to 1.5 mmol/liter.

Diabetic ketoacidosis (DKA) on the other hand, is when there is a dangerously high amount of ketones present in your blood ranging from 1.6 mmol/liter to greater than 3.0 mmol/liter.

Diabetic ketoacidosis is prevalent in type 1 diabetics when blood sugar is too high and occurs from a lack of insulin. It’s imperative to test blood sugar levels throughout the day to ensure you are in the proper ketone level range. The American Diabetes Association (ADA) recommends testing your ketone levels if your blood sugar is any higher than 240 mg/dL.

Aside from the confusion in terminology, there are no negative consequences to adopting a low carb, high fat ketogenic diet for type 2 diabetics when done correctly.

Getting Into Nutritional Ketosis

Entering ketosis boils down to restricting your total carbohydrate intake and replacing those carbs with healthy fats instead.

When your body is depleted of its glycogen (or stored glucose), it begins to use fats as energy.

Once your body is deprived of glucose, ketones are produced.

Ketones are small energy molecules that replace glucose for energy.

The longer you stick to this way of eating, the more efficient your body becomes in metabolizing fats as its main source of fuel.

Utilizing ketones to your metabolic advantage as a diabetic can help prevent excess blood sugar from harming your pancreas and insulin production.

The common macronutrient ratio for a standard ketogenic diet requires eating 70-80% fats, 5-10% carbs, and 20-25% protein.

It’s important to consult with your primary physician before starting a ketogenic diet, especially if you are on any diabetes medication.

Some diabetics steer away from keto due to the assumption that cutting carbs (like fruits) prevents you from getting essential nutrients you need to stay healthy — but that’s not the case.

The truth is, incorporating nutrient-dense, keto-friendly vegetables like kale, spinach and collard greens into your ketogenic diet will give you even more vitamins and minerals your body needs to function optimally. These vegetables contain large amounts of essential micronutrients like magnesium, vitamin A and vitamin C.

Monitoring Your Diabetes on a Keto Diet

Unlike other low calorie diets, a ketogenic diet will require extreme attention and monitoring.

In some cases, starting the diet in a hospital might be required so your doctor can monitor both blood glucose and ketone levels to ensure the diet isn’t causing any adverse effects.

Once your body is acclimated to using ketones as energy, you should still make it a priority to regularly visit a physician to make sure the ketogenic diet is working properly for your body.

Even when your diabetic symptoms begin to regulate and improve, keeping up with regular blood glucose monitoring is imperative.

Keto’s Promising Effects on Blood Glucose

A ketogenic diet works well for many type 2 diabetics because it restricts carbohydrates.

Carbohydrates are converted into sugar in the body, and when large quantities are consumed, they can cause massive blood sugar spikes. They’re the macronutrient that raises blood sugar the most, which is why drastically reducing how many you eat can help normalize your blood glucose levels.

One convincing study from 2016 found that a low carb diet improved blood glucose levels and helped with weight loss in adults suffering from type 2 diabetes[*].

By the end of the 10-week, low carb study, nearly 60% of the 262 type 2 diabetics reduced their diabetes medication or stopped taking it altogether.

Each subject was required to consume no more than 30 grams of carbs per day while increasing fats and proteins. In other words, they followed a ketogenic diet — it just wasn’t called that.

Several smaller studies show similar positive results.

How Does Fat Help Prevent Diabetes?

The Diabetes Prevention Program conducted a study that followed 1,079 people with prediabetes. The results showed that 58% were able to prevent the progression of diabetes simply through losing weight and changing their diet[*].

And while the ketogenic diet isn’t a one-size-fits-all diet for diabetics, studies show this high fat way of eating can drastically aid with weight loss[*][*][*].

Increasing your fat intake helps regulate hormones — including your hunger hormone, ghrelin — helping mitigate any major food cravings. Having balanced hormones helps with the prevention of diabetes because the body doesn’t crave large amounts of carbohydrate or sugar. This helps blood sugar levels in diabetics normalize.

Another study performed by researchers at the Duke University Medical Center took 28 overweight people who had type 2 diabetes. During the 4 month trial, they consumed a low carb, high fat ketogenic diet while simultaneously tapering off diabetes medications.

Researchers concluded that there was a 16% decrease in Hemoglobin A1c (HbA1c), one of the main markers of diabetic health. Additionally, they lost an average of 19 pounds each, their triglyceride levels decreased by 41% and their blood sugar levels decreased by 16%[*].

So clearly, eating more fat doesn’t make you fat! In fact, it can have quite the opposite effect and help you lose weight and regulate hormones when you also cut carbs.   

What Happened to Saturated Fats Being Bad for You?

Many people are hesitant to follow the ketogenic diet because of its relatively high saturated fat content — and we all know how much saturated fat has been villainized over the past few decades.

People with diabetes have been told to consume no more than 10% of their calories from saturated fat[*].

Luckily, there is research suggesting that consuming more saturated fat as part of a low carb diet can be beneficial for overall health, particularly if you have risk factors for diabetes and want to lose weight.

One study in particular looked at 83 adults with a BMI of 33 (technically obese) and a high risk for type 2 diabetes. They proceeded to divide them into three different diets with the same caloric intake[*].

One diet was a very low fat diet, consisting of 20% protein, 70% carb and 10% fat.

The second diet was a high unsaturated fat diet containing 50% carb, 30% fat and 20% protein.

The third diet was a very low carbohydrate diet with 20% protein, 61% fat and only 4% carb.

For each diet, 20% of the total fats were saturated and the subjects were placed on an exercise regimen.

At the end of the 3 month study, there was an almost identical amount of body fat loss between the three diets. But the big surprise was that, compared to the other groups, the very low carbohydrate diet group had improved markers of HDL “good”  cholesterol.

Additionally, insulin levels decreased by 34% in the very low carb group, decreased by 18% in the high unsaturated fat group, and actually increased by 15% in the very low fat group[*].

This evidence proves that low carb, high fat ketogenic diets provide identical weight loss properties while simultaneously lowering overall insulin levels compared to other diets. Saturated fats shouldn’t be of concern if you have diabetes or are pre-diabetic as long as you are consuming them in conjunction with a proper ketogenic diet.

Is the Ketogenic Diet Safe for Other Types of Diabetes?

With the overwhelming evidence supporting the ketogenic diet as a way to prevent diabetes, there are some precautions that need to be considered.

First, if you have a kidney disease — commonly associated with poorly managed diabetes — the ketogenic diet may not be a good idea because it requires you to limit the amount of protein in your diet. But you can always consult with your doctor just to be sure.

If you have another form of diabetes, you should also proceed with caution.

Is Keto Safe for Women with Gestational Diabetes?

There is a lot of debate behind what diet you should follow if you’re pregnant and/or have gestational diabetes (GD). The general “safe” consensus among mainstream health experts is that you should not follow a ketogenic diet.

Many experts believe that a higher carbohydrate diet is best for pregnant women with GD. Some doctors are convinced that having ketones present in the urine of pregnant women with GD is dangerous and can lead to conditions of diabetic ketoacidosis.

But the truth is, being in ketosis is a natural part of being human (it always has been) and while there aren’t many studies on GD and the ketogenic diet, if you dig around, you’ll find several positive anecdotal accounts of the ketogenic diet being beneficial for women with GD.

So the answer isn’t so straight forward. Adopting a ketogenic diet might help mitigate symptoms of gestational diabetes, but it should be done with extreme caution and medical supervision.

Eating a low carbohydrate (but not full on keto) diet including some fruit may be a better approach to help prevent and manage gestational diabetes.

Be sure to consult with your obstetrician before making any dietary changes so they can help guide you through the process.

Is Keto Safe for Type 1 Diabetics?

The short answer is maybe. The long answer is a little more complicated.  

Type 1 diabetes is different because the pancreas has an inability to produce insulin whereas with type 2 diabetes, the pancreas still produces insulin.

When your body doesn’t produce insulin, sugar can’t enter your body’s cells. So instead of fueling the cells, sugar circulates in your bloodstream causing high blood sugar levels.

When there’s no insulin present to deposit blood sugar into the cells, the excess blood sugar increases, otherwise known as diabetic ketoacidosis. This is highly dangerous because it causes the blood to become acidic rather than having a neutral pH level[*].

This is all to say that the ketogenic diet may not have quite the same beneficial properties for type 1 diabetics compared to type 2 — and that a keto diet definitely can’t cure type 1 diabetes.

However, some doctors — like Richard Bernstein, MD, who manages his own type 1 diabetes with a very low carb approach[*] — believe that ketogenic diets can help prevent blood sugar levels from spiking as greatly.

Eating a low carb diet may put people with type 1 diabetes at somewhat greater risk for low blood sugar, but managing low blood sugar with something like a glucose tab is generally considered easier than managing high blood sugar with an insulin shot.  

Halle Berry is one vocal keto dieter who swears by this low carb approach to help control her type 1 diabetes and maintain a healthy weight[*].

Unfortunately, there aren’t any notable studies that prove the efficacy of the ketogenic diet with type 1 diabetes.

Definitely speak with your physician before altering your diabetes care plan or using the ketogenic diet to manage your type 1 diabetes.

The Ketogenic Diet May Drastically Improve Your Diabetes

The overwhelming amount of evidence shows that a ketogenic diet can be extremely beneficial long-term approach for diabetes prevention and diabetes management. Specifically, keto can help people with or at risk for type 2 diabetes by:

  • Promoting weight loss
  • Improving insulin sensitivity
  • Regulating your hunger hormones to reduce food cravings
  • Increasing levels of good cholesterol
  • Improving HbA1c markers

But it’s important to remember that no diet is one-size-fits-all.

The ketogenic diet is optimal for type 2 diabetes but should be considered with caution if you have type 1 or gestational diabetes.

If you have diabetes and want to try a ketogenic diet, your first step should be to consult with your doctor to determine whether a low carb, high fat lifestyle is for you, especially if you are currently on any medication. You’ll also want to monitor your blood glucose and ketone levels closely while on a ketogenic diet to ensure there are no adverse effects.


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Responses (1)

  1. im type 2 diabetes ,im 35 years old male, im about 230 pounds . if i do the low carb keyogenic diet , would i be able to reverse diabetes?

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