Diet is certainly one of the main factors deciding about our health, together with our genes and the level of physical activity. Someone once said: “You are what you eat”, and it seems very true if we think about our inappropriate eating habits often leading to diseases like obesity or diabetes, sometimes occurring together as diabesity and currently being a “pandemic” of the modern, Western societies. 

Bad eating behavior has its health consequences. On the other hand, a properly adjusted diet can help control different diseases. In the context of Type 2 diabetes, well-designed diets that focus on healthy meals including lean protein, vegetables, nuts, and fruits, may help better regulate high blood glucose levels, reduce weight, and prevent cardiovascular complications related to elevated cholesterol levels and hypertension. Nowadays, many diets are being recommended as a remedy against diabetes, including Mediterranean, vegetarian, or vegan eating plans. Among many options available today, one particular diet is catching the attention of both clinicians and patients with type 2 diabetes. It is the so-called ketogenic (keto) diet,  which was originally developed in the 20th century to treat epilepsy

How does the keto diet help with diabetes?

The traditional keto diet is based on a very low consumption of carbohydrates, 2050g a day, accompanied with adequate protein plus healthy fats.  In regular conditions, the energy necessary for different cellular processes comes from carbohydrates. They are present in many foods we consume every day, including bread, rice, pasta, fruits and sugar. Under a keto diet where carb consumption is limited and it’s replaced with a high intake of fats, our cells are being trained to switch to fat burning. This promotes relatively fast weight loss. By restricting carbs and making the switch from glucose to fat to generate energy, keto diets lower blood glucose levels and make our bodies more sensitive to insulin, the hormone which regulates glucose levels in the blood. Carbs are the main driving force of insulin production. Reducing carb intake can reduce the load on the insulin-producing beta cells in the pancreas and improve their ability to control blood sugars. Both effects, weight loss and low blood glucose, are for sure beneficial to achieve a better control of diabetes.

A middle age female diabetic patient testing her blood sugar at home prior to eating a healthy meal.
The keto diet has been shown to improve blood glucose levels and insulin sensitivity.

What are the effects of the keto diet on diabetes management?

An analysis based on clinical data from different studies assessing the effects of keto diets against low-fat diets suggests that the former improve metabolic parameters more effectively, including blood glucose and insulin sensitivity. Another study showed a significant improvement in fasting blood glucose and glycated hemoglobin levels in subjects with type 2 diabetes who followed a keto diet for 4 months, compared to those who followed a low-calorie diet (500-1000 calories daily).

A low-carb ketogenic diet may even be more beneficial than the eating plans for diabetics recommended by the American Diabetes Association (ADA), which allow for higher consumption of carbs.  A study that compared the efficacy of a very low-carb keto diet with the low-fat “plate method diet” recommended by the ADA found that the keto diet, along with lifestyle recommendations like mindful eating,  helped control blood glucose and enabled more efficient weight loss after 32 weeks. A study that compared a low- fat, high-carb diet with a high-fat, low-carb diet found that the latter led to lower dependency on diabetes medications and better blood sugar levels throughout the day, indicating that a keto diet focused on high-fat, low-carb foods  is better suited for the treatment of type-2 diabetes. 

A keto diet may also lead to improvements in blood lipids. A 2020 meta-analysis found that the keto diet significantly reduces blood sugar levels and increases high-density lipoprotein (HDL, or  ‘good’ cholesterol).

Lastly, type 2 diabetes control can be achieved when a keto diet is combined with intermittent fasting. A case report indicated that a 14-month diet regimen based on a keto diet (80% fat, 15% protein and 5% carbs) and intermittent fasting largely improved glycemic control and minimized the need for pharmacotherapy in a 57-year old woman suffering from type 2 diabetes. 

What low-carb, high-fat foods can I eat on the keto diet?

Examples include:

  • Meat and poultry
  • Eggs
  • Fatty fish, such as salmon
  • Avocados
  • Plant-based oils such as olive, avocado, and coconut oil
  • Cheese
  • Nuts, such as almonds, walnuts, cashews, and macadamia nuts
  • Chia seeds and flaxseeds

 You can fit a variety of fruits and vegetables into a keto diet while staying under 50 grams of carbohydrates per day. Here is an example list of fruits and vegetables that you can enjoy on the keto diet:

  • Strawberries
  • Blackberries 
  • Blueberries
  • Raspberries 
  • Peaches
  • Apricots
  • Avocados
  • Asparagus 
  • Broccoli 
  • Brussels sprouts 
  • Cabbage 
  • Carrots
  • Swiss chard 
  • Cucumbers
  • Kale
  • Romaine lettuce 
  • Mushrooms 
  • Peppers 
  • Spinach
  • Tomato 
  • Zucchini 
Keto, ketogenic diet, low carb, healthy food background, top view.
The keto diet is focused on low-carb, high-fat foods. These include lean meats, fruits, vegetables, nuts and seeds, and healthy plant oils.


What are the side effects of following a keto diet ?

Side effects are usually mild and short-lasting and include headaches, diarrhea, sweating, frequent urination, fatigue, anxiety and/or irritability, hunger, tachycardia, lightheadedness, and shakiness. These can be managed with a high intake of fluids and electrolyte supplementation.

For how long can I follow a keto diet to treat type 2 diabetes?

The positive effects of the keto diet for diabetes control seem to occur within a few months of following the diet. However, studies of more than two years following the keto diet are lacking, and its long-term effects are unknown. The available studies suggest that the keto diet can safely be used  for up to two years without major side-effects.

Given these safety concerns, as well as how much our body depends on carbs for energy, It may be hard to stick to a keto diet long-term. If you do return to eating carbs, it’s important to pick high-quality sources, such as whole grains, and to avoid processed foods and added sugar.  Choosing carbs that are also high in fiber, such as oats, quinoa, and beans, reduces the risk of heart disease and type 2 diabetes, while also helping with weight loss and blood sugar control. 

We need to remember that to fully take advantage of any specific diet and use it in a safe way, we need to adjust it properly to our individual situation. The best way to achieve that is by talking to a doctor and consulting a qualified dietician to help us elaborate a plan, best tailored to our needs and health status. 

The above is not medical advice. Prior to changing your diet, you are encouraged to consult a qualified health professional