The Ketogenic Diet for Diabetics: How It Really Works

One of the most popular uses of the keto diet is for managing type 1 and type 2 diabetes. But what is it about this diet that makes it so popular among those tackling such conditions?

In 2014, there were over 400 million people diagnosed with diabetes globally 1. As these numbers continue to rise, researchers are looking for strategies to alleviate the global burden of diabetes. The ketogenic diet for diabetics is one such strategy recently gaining recognition.

Because the keto diet has minimal impact on blood sugar, it can help control their condition without medication. There are countless studies proving that keto is effective in lowering blood glucose levels and even increasing insulin sensitivity. Keto also helps you lose weight, which is very important when managing diabetes.

In this article, we talk in detail about the ketogenic diet for diabetics. You will learn how exactly keto works for diabetes, if it can cure diabetes, and how safe it is for treating diabetes. But first, let’s start by talking a bit about why people get diabetes in the first place and how this disease is traditionally treated.

About Diabetes

Diabetes mellitus, commonly known as diabetes, is a group of metabolic disorders where people have elevated blood sugar (glucose) levels over a long period of time. This happens because their pancreas is not making enough insulin, or their cells don’t respond to insulin (insulin resistance).

Insulin is a hormone that allows glucose to enter cells for energy production. When there’s any problem with insulin, the cells are deprived of its main energy source. This can lead to many complications such as hyperglycemia, ketoacidosis, cardiovascular disease, kidney disease, foot ulcers, and eye damage 2.
There are three types of diabetes, all with different causes:

Type I diabetes

Also known as insulin-dependent or childhood diabetes, type I diabetes is a result of the pancreas not making enough insulin.

This type requires daily insulin injections. Its symptoms include excessive urination, excessive thirst, constant hunger, losing weight without trying, blurry vision, and constant tiredness. These symptoms occur suddenly and are severe.

Researchers believe that type I diabetes is an autoimmune condition where the immune system is attacking insulin-making cells 3. The condition typically starts in childhood, but adults can also develop it.

Type II diabetes

This is the most common type, comprising 90% of all diabetes cases. Type II diabetes is a result of the body not responding to insulin. It’s the result of being overweight or physically inactive.

Symptoms are similar to those of type I diabetes, but less severe and they come on gradually. As a result, people may not realize they have diabetes for many years and get an official diagnosis once they develop complications.

Gestational diabetes

Gestational diabetes refers to high blood sugar during pregnancy. It usually disappears after giving birth but can still be dangerous if not managed. Most women who develop gestational diabetes do so in the second trimester.

Symptoms are similar to those of other types of diabetes. However, most women get a diagnosis through prenatal screening rather than reporting their symptoms.

Besides these three types, you may have also heard about pre-diabetes. This condition is also called impaired glucose tolerance. It leads to high blood sugar and may precede diabetes by many years. Having your blood sugar levels measured can help stop prediabetes from progressing into diabetes.

Treating Diabetes

Most medical experts say that diabetes is a chronic disease with no cure. However, never studies show that there is hope for people with diabetes. For example, a 2013 scientific article explains that obese people who lose 15-20% of their body weight often experience reversal of diabetes 4.

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Whether or not diabetes is curable is still open to debate. But one thing is for sure: you need to control and manage diabetes. Uncontrolled, diabetes can be dangerous and deadly even. Here is how doctors usually treat this condition:

Insulin shots and medication

Daily insulin injections are essential to keep those with type I diabetes alive. Sometimes, insulin shots are also prescribed to those with type II diabetes as well. People also treat type II diabetes with Metformin, a drug that improves insulin sensitivity.

Healthy diet

Diabetes is a condition of impaired glucose metabolism. That’s why doctors recommend changing your diet to manage diabetes. Eating three meals a day at regular intervals helps. These meals should consist of whole grains, whole foods, fiber, and good fats according to medical experts 5.

However, because carbohydrates have the greatest impact on blood glucose, diets that limit carbs are of greater help. The keto diet, being the ultimate low-carb diet, is a powerful defense against high blood sugar levels. We’ll get into more detail on this later on.


A 2016 systematic review shows that walking for just 30 minutes every day reduces your risk of type II diabetes by 50% 6. Regular exercise helps:

  • Improve insulin sensitivity
  • Lower blood pressure
  • Manage weight
  • Reduce stress levels

In turn, all these things help with diabetes. However, the most important thing to take note of is that exercise is essential for metabolic health and insulin sensitivity. A lack of physical activity makes your muscles less sensitive to insulin.

The Ketogenic Diet for Diabetics

When it comes to managing diabetes, controlling blood glucose levels comes first. Avoiding foods that cause blood sugar spikes like sweets and refined grains is one way to do this. Taking insulin is another way.

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But the best way by far is following the ketogenic diet. Being the ultimate low-carb diet, keto effectively lowers blood sugar levels almost instantly 7. With carbs limited to below 50 grams a day, there’s no way your blood glucose levels will reach unhealthy levels.

Even compared to low-glycemic index diets, studies also show that keto is more effective simply because it allows for less carbs 8. But keto also boosts insulin sensitivity by helping you maintain a healthy weight and increasing energy.

But how to follow keto when you have diabetes? Here’s what you may want to consider:

Cut back on carbs gradually

The keto diet reduces carb intake to 20-50 grams per day or 5-10% of your daily calorie intake. For comparison, the standard Western diet involves eating 225 and 325 grams of carbohydrates a day or 45-65% of your daily calorie intake 9.

That’s a pretty drastic change? Such a change isn’t a problem for people with normal glucose metabolism. But for those with diabetes, a sudden change in carb intake can cause hypoglycemia. That’s why cutting back on carbs slowly is so important for people with diabetes.

We suggest a gradual decrease of 20 grams net carbs per day optimal. Do this for up to 2 weeks until you reach a carb limit optimal for your weight and activity levels. To know how many carbs you should eat for ketosis, visit our Keto Calculator.

Speak to your doctor

Chances are you are taking insulin to manage diabetes. When you start the keto diet, you won’t need as much insulin as when your diet was essentially based on carbs. That’s why you should speak to your doctor about lowering your insulin dose.

After a while of being on a keto diet, you will stop relying on insulin completely, unless you have type I diabetes. Remember, your body still needs insulin, even if it’s not burning carbs for fuel. That’s because insulin helps control ketone production in your body to keep ketones at normal levels.

Test blood glucose and ketones

You’re already doing this. However, on a keto diet you may need to check your blood sugar and ketone levels more frequently. This is especially true if you have type I diabetes. This type puts you at risk of ketoacidosis, which is a condition resulting from having too many ketones in the blood making it acidic.

If your test shows you’re hypoglycemic or have blood ketone levels between 0.6 to 2.9mmol/L. This can mean you are at risk of ketoacidosis and may need to GP as soon as possible to avoid complications. You may also want to take more carbs to prevent ketoacidosis.

Ketogenic Diet for Diabetics: Is It Effective?

We already mentioned that low-carb, ketogenic diets outperform low glycemic index diets when it comes to controlling blood sugar levels. But what about the effectiveness of keto as a long-term strategy? Is it in any way better than traditional diabetes treatment?

A 2017 study on overweight adults found that keto led to more weight loss than a low-fat diabetes diet over 32 weeks 10. A 2013 review found that keto diets are safe and effective tools for blood glucose control and that they don’t increase the risk of cardiovascular disease 11. The same review also noted that keto diets reverse kidney damage from diabetes.

Furthermore, one study followed 105 overweight adults with type II diabetes to see how a low-carb and low-fat diet compared in managing diabetes 12. After one year, both diets were equally effective for weight loss but keto increased HDL (good) cholesterol levels.

And as far as the effectiveness of keto for type I diabetes specifically, a case study involving a 19 year old male is promising 13. After just 2 months on the keto diet, the subject experienced a rise in C peptide levels. The researchers concluded that this proves keto has the potential to reverse autoimmune processes that destructing pancreatic beta cells in type I diabetes.

Importance of Exercise

Although numerous studies prove that the ketogenic diet for diabetics is effective, it can only do so much. Without major lifestyle changes, you can’t expect the keto diet to work. This is especially true in regard to exercising.

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Moderate to intense workouts at least 4 times a week helps you lose weight, improve insulin sensitivity, increase metabolic rate, and more. A combination of aerobic and resistance training will do wonders for your metabolism functioning and overall well-being.

Some popular exercises on keto include:

Aerobic workout

Examples include running, swimming, brisk walking, hiking, and similar. These exercises make your heart beat faster and make your breathing harder increasing your oxygen intake. These workouts improve blood volume in muscle tissue and also protect cardiovascular health.

Anaerobic workout

Weight-lifting and high-intensity interval training (HIIT) are good examples. During these workouts, oxygen demands exceed oxygen available through breathing. Besides that, anaerobic exercise spends energy stored in the muscles (i.e. glycogen). These workouts are great for building muscle and losing weight.

Flexibility workout

Pilates, yoga, and stretching are all workouts that improve your flexibility. These do not boost weight loss, but they do keep your joints healthy and improve your posture. They also calm you mind and reduce stress levels. Most flexibility workouts are also combined with stability exercises.

Make sure that the workout you choose fits your lifestyle and limitations. You also want your workouts to be enjoyable in order to keep yourself motivated. As for the effectiveness of regular exercise in managing diabetes symptoms, one meta-analysis shows that regular exercising improves insulin sensitivity for at least 72 hours post-workout 14.

But Is It Safe?

Yes, the ketogenic diet for diabetics is safe when you follow it accordingly. Monitoring your blood glucose and ketone levels and eating a wide range of keto-friendly foods will keep you in optimal health.

Still, the keto diet is extreme in a sense, and like with all things extreme – precaution is necessary. Two things you need to watch for on keto are:


Hypoglycemia is having dangerously low blood glucose levels. Symptoms include feeling clumsy, confusion, trouble talking, and loss of consciousness. Some people also report shakiness, sweating, and hunger. The symptoms typically come on quickly.

In diabetics, taking insulin increases the risk of hypoglycemia. To lower your risk on a keto diet, we already explained that you need to cut back on carbs gradually and talk to your doctor about adjusting your medication.


Insulin controls, among other things, the amount of ketones your body makes. When there’s not enough insulin, ketone production can go overboard to dangerously high levels. Because ketones are acidic, their increased numbers can change the pH of your blood which is dangerous.

In people without diabetes and even oftentimes in those with type II diabetes, the risk of ketoacidosis is low. However, the risk is highest in those with type I diabetes duet to an impaired production of insulin.

Gestational diabetes

We don’t recommend that pregnant women follow the ketogenic diet. And we especially don’t recommend treating gestational diabetes with keto. Why is that? Because pregnancy places extraordinary demands on your body and because your doctor needs to help you manage gestational diabetes.

Besides that, there aren’t enough human studies examining the safety of keto during pregnancy. Some animal studies found that keto had a negative impact on embryo development 15. Human studies did not find any major problems, though 16. Still, we suggest playing it safe and avoiding keto while pregnant and breastfeeding.

We have no idea how ketones affect a baby’s development and how important circulating glucose is for pregnancy. Managing diabetes when pregnant is also tricky without insulin medication and even studies show that keto seems ineffective when it comes to this particular type of diabetes 17.


The ketogenic diet is the ultimate low-carb diet. As such, it’s no wonder both medical experts and ketoers have considered it for diabetes management. And as it turns out, studies show it really does work where diabetes is concerned.

The keto diet effectively lowers blood sugar levels and even boosts insulin sensitivity. It’s also great for weight loss and boosting energy levels – two very important things when treating diabetes.

However, you need to be careful when going keto with a diabetes diagnosis. Hypoglycemia and ketoacidosis are problems that happen when diabetics change their diet. Make sure to speak to your doctor about your plan to go keto to manage diabetes to avoid both problems. Also, if you’re pregnant and diabetic, it’s a good idea to look for conventional ways to treat gestational diabetes for safety reasons.


  1. World Health Organization. Diabetes. 2018 October 30 -

  2. World Health Organization. Diabetes. 2013 March -

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