Diabetes is said to be a ‘progressive, chronic’ disease – incurable, in other words. Recently, case reports and clinical studies have accumulated claiming diabetes reversal with a low-carb or ketogenic diet. Many will debate if ‘reversal’ is the right term since adding in sugar and flour will bring their diabetes back. Nevertheless, there remains no doubt that people with diabetes benefit from these kinds of diets . For diabetics, both type 1’s and type 2’s, a well-formulated low-carb or ketogenic diet should be the first line of lifestyle treatment.
Before going deeper into the topic let’s first clarify what diabetes is and how a ketogenic diet is defined.
What’s a keto diet?
A ketogenic diet is very low in carbs, high in fat and moderate in protein. For a weight stable person, no more than 5% of calories should come from carbs, 70-80% from fat and 20-30% from protein. With this macronutrient-distribution, individuals do not rely on glucose as a major source of energy but use fat for fuel instead. Fat is used to produce ketone bodies, which are used for energy or to regulate certain genes. Two ketone bodies circulate in in your blood: Acetoacetate (AcAc) and Beta-hydroxybutyrate (BHB). A third ketone, acetone, is spontaneously created from Acetoacetate. It is not a source of energy but is useful for ketone measurement. Check our ketone measurement guide to learn more.
Because the ketogenic diet replaces carbs with fat, it keeps blood sugar levels low, reduces the need for insulin and has an overall positive effect on insulin signaling. We will describe further down why this is so crucial for diabetics.
Diabetes is diagnosed when your fasting blood sugar is above 125 mg/dL or your HbA1c (poor proxy for 3-month average fasting blood sugar) is above 6.5%. However, that’s not what the disease is, that’s just how doctors diagnose it – uncontrolled blood sugars. The disease exists way before you see high and unstable blood sugar levels.
Diabetes is actually a metabolic problem when the hormone insulin can no longer exert its important actions appropriately (your tissues don’t ‘hear it’ knocking). So you produce more and more insulin, fatiguing your pancreas. This deluge of insulin (hyperinsulinemia) also causes your fat stores to release fat inappropriately, ultimately swamping your liver with excess fat (energy) which your liver handles by pumping out lots of blood glucose in a frantic manner in an effort to balance things out.
There are two different types of diabetes, type 1 and type 2 and they differ in their causes.
Type 1 is an autoimmune disorder where autoantibodies attack the insulin-producing β-cells in the pancreas . As a consequence, type 1 diabetics produce hardly any insulin. They need to inject insulin to cover what’s called their ‘basal insulin’ need. They run into issues when trying to cover their carb intake too, which we’ll get to.
Type 2 is caused by environmental factors leading to increased insulin resistance, like the 3 big dietary factors: sugar, flour and seed oils. To understand what insulin resistance is, let’s first have a look at insulin’s role in the body.
Insulin has 2 main tasks, to cycle fats into and out of your fat stores appropriately and also keep your blood sugars stable [3, 4]. An increase in blood sugar stimulates insulin release in the pancreas. Insulin then binds to insulin receptors, which unlocks glucose channels so that glucose can enter the cells.
A second important task of insulin is lipid storage . As long as there is dietary glucose entering the bloodstream it will be taken up by the cells with the help of insulin. This also lowers the use of fat as fuel.
As long as insulin is present, fatty acids are stored away, preferentially in adipose tissues. Insulin also suppresses lipolysis, the release of free fatty acids from stored fat. Insulin resistance is the opposite of insulin sensitivity; insulin-sensitive means that cells respond well to a little insulin and insulin resistant means that they need more insulin to respond appropriately.
With increasing insulin resistance, these physiological processes get disturbed. But what causes insulin resistance?
Before the discovery of insulin in 1921, a low-carb diet was the only way to treat diabetes because uncontrolled blood sugar causes organ damage and has dramatic consequences.
Despite the medical progress within almost 100 years, a diabetic’s risk of contracting heart disease has not decreased. In other words: a low carb or ketogenic diet is still the best treatment option for diabetes!
This does not mean that you should stop taking your medication straight away. Knowing how to use some medical drugs on a keto diet is your best bet. And your doctor might soon agree that you don’t need your medication anymore.
There are 2 kinds of insulin resistance in a sense. In diabetes, we see pathological (meaning bad) insulin resistance. On a ketogenic diet, we see physiological (meaning normal) insulin resistance.
The ketogenic diet diverts blood sugar preferentially towards your brain and less towards your muscle by making your muscles insulin resistant. So your brain is kept happy with its 30-50% glucose requirements and your muscle can do without the glucose by happily burning away fatty acids. This is normal metabolic flexibility.
In diabetes, you’ve got generalized insulin resistance that is metabolically inflexible, making you a poor fat burner and hyper-reliant on glucose. This is damaging to your cells and organs. It results in glycated tissues and peroxidized fats that essentially age you, increasing your risk of heart disease, cancer and even losing a limb!
Insulin resistance is caused by several mechanisms, one of which is chronically elevated insulin levels. So what increases insulin levels? Mainly sugar. A poor nights sleep can do it too, but sugar is a big one. This can be sugar that is part of our diet or carbohydrates that are broken down to sugar. Proteins put together with fats can also be converted into sugar, a process called gluconeogenesis, but it is really the effect of dietary refined sugars and starches (flour) causing blood sugar and insulin spikes. These spikes are then often followed by a blood sugar crash, leading to a sense of discomfort, even sweating, and usually a craving for more high-carb foods.
When we eat this carby kind of food multiple times per day with little time in-between meals, insulin levels are consistently high throughout the day. Over the years, cells react to this constant overflow of glucose and fat by shutting down their insulin receptors. With fewer insulin receptors, cells become less sensitive to the action of insulin. For the same amount of glucose to be taken up, the pancreas has to produce more insulin.
Not only cells that use glucose as fuel become insulin resistant but also chronically inflamed fat cells. When they become insulin resistant, they take up fewer circulating lipids despite high insulin levels. Insulin resistance also increases the release of free fatty acids from fat storage. Free fatty acids in the blood reduce the glucose uptake into muscle cells and further contribute to insulin resistance.
Insulin resistance is often characterized by high triglycerides, as well as a high ratio of triglycerides to HDL-cholesterol.
Another organ that plays an essential role in blood sugar regulation is the liver. It stores excess glucose as glycogen, and when glucose levels are low, glycogen is broken down to provide glucose . This process is regulated by two hormones: insulin and glucagon. Insulin normally promotes glycogen synthesis and interferes with glucose release from the liver.
With increasing insulin resistance, the liver may release glucose despite the presence of insulin. Another mechanism how insulin resistance leads to an increase in blood sugar.
Insulin resistance becomes worse over time, so more and more insulin has to be produced.
At some point, the pancreas is literally burned out and can’t produce enough insulin to keep even basic blood sugar under control, let alone after a high-carb meal. This state is end-stage of type 2 diabetes where insulin injections become necessary . Type 2 diabetics do not produce less insulin than normal, but the insulin resistance increases the need for insulin. A diabetic pancreas is eventually unable to supply this increased demand.
This sounds like a vicious cycle, and it is! More and more insulin is needed, and increased amounts of insulin further exaggerate insulin resistance. Is there a way to escape this cycle?
Good news: yes, there is a way!
When ever-increasing amounts of insulin aggravate insulin resistance, it only makes sense to keep insulin levels as low as possible. Does this make sense? You may notice that this is the exact opposite of the standard treatment for diabetics. They receive external insulin to overcome the inability of the pancreas to produce sufficient amounts of the hormone.
Because insulin resistance becomes worse over time, diabetics need more and more external insulin over the years.
So how do you keep your insulin low? You have to decrease the need for insulin. Insulin is needed to shuffle glucose, fats, and proteins into the cells, and if we reduce the amount of glucose in the blood, there is less need for insulin.
You might suspect already that a low-carb or ketogenic diet can help a lot – there’s basically no sugar! On a keto diet, we eliminate everything that causes blood sugar spikes. As a consequence, blood sugar is stable and at healthy levels.
Insulin is still required, but only in modest amounts. The less insulin is released, the faster it will disappear again. In between meals, there is plenty of time for blood sugar and insulin to come down. Because you rely on fat instead of glucose for energy, you also eat less frequently on a ketogenic diet, giving your cells even more time without exposure to insulin.
You may even fancy trying intermittent fasting, an excellent method to further increase insulin sensitivity. For further details, check our guide about intermittent fasting.
The decreased exposure to insulin restores insulin sensitivity over time, or in different words reduces insulin resistance. This means that cells become responsive to insulin again and less insulin is needed to perform its function.
Can you reverse diabetes type 2 with a ketogenic diet?
The answer to this question is yes. Many advocates of the ketogenic diet say yes because the diet restores insulin sensitivity, and as a consequence, diabetes symptoms disappear. The ketogenic diet allows diabetics to live a normal life and even come off their insulin entirely (if they retain sufficient insulin secretion capacity).
The counter-argument is that diabetes is not reversed because it will come back soon after starting to eat lots of sugar and refined carbs. How much time is soon? It is difficult to say how “soon” diabetes will come back, and the time it takes depends on many factors. It is, however, true that the ketogenic diet does not set the body back to zero and allows for another few decades of unhealthy eating. On the other hand: every adult with a high sugar/high carb history has a high risk of becoming diabetic. It is just a matter of time.
We also need to define “reversible”… that’s not easy. But what matters is that a low-carb or ketogenic diet increases metabolic flexibility and decreases pathological insulin resistance. In so doing it decreases cardiovascular risk factors and improves overall health. Many diabetics don’t even need external insulin or other diabetic medications when following a ketogenic diet.
Type 1 diabetes is not caused by insulin resistance, but it still makes sense to lower the need for insulin. Because type 1 diabetics hardly produce any insulin, they rely on external insulin when following a standard high-carb diet. Through carb restriction, a ketogenic diet decreases the need for insulin. In some type 1 diabetics, their insulin production is sufficient when following a ketogenic diet. Others still need to inject insulin, but much less than on a high-carb diet. Overall, it is much easier to control blood sugar levels with injected insulin on a ketogenic diet because blood glucose raises only mildly after meals.
In fact, a recent survey of the TypeOneGrit Facebook group established the valuable proof-of-principle. Managing type 1 diabetes with a well-formulated ketogenic diet results in astonishingly improved control of blood sugars . In the words of the authors, they say “exceptional control of T1DM without increased risk of adverse events”.
What should a diabetic eat on a keto diet?
The ketogenic diet is by definition ideal for diabetics, no matter if they have type 1 or type 2 diabetes. However, they need to follow it more strictly since it is a real therapy for their disease.
The most important thing that diabetics have to learn is that there is no reason to avoid fat, not even saturated fat. It is not saturated fat that causes arteriosclerosis and heart disease, but an excess of refined carbohydrates like sugar and flour. Seed oils are implicated in the disease although by other mechanisms that involve damaged lipids and mitochondrial toxins.
Healthy fats are crucial on a ketogenic diet, but people who have been following the official dietary advice don’t know what healthy fats are. In short: all natural fats that you find in fish, meat, nuts, olives, coconut, and full-fat raw dairy products are healthy for diabetics. On the other hand, oxidized seed oils and the trans fats in margarine should be avoided. Learn more about good fats vs bad fats here.
The same is true for meat. You’ve probably been told to avoid red meat when in fact you should not. Meat is an integral part of any diet including the ketogenic diet. There is no reason to avoid it (OK you’re excused if you’ve been bitten by a lone star tick!). The ketogenic diet reduces cardiovascular risk factors and improves the lipid profile by increasing HDL and lowering triglycerides [9,10].
These foods belong to a ketogenic diet:
– All kinds of meat, organ meats, seafood, and fish – Nuts and seeds – Vegetables, preferably leafy greens and mushrooms – Small amounts of low-sugar fruits, such as berries (and even smaller amounts of starchy vegetables like carrots) – Full-fat dairy products and eggs
– Coconut oil, olive oil, butter, ghee and lard