The high-fat nature of ketogenic diets might seem a strange option for those with type 2 diabetes, but this low-carb way of eating can ease diabetes symptoms by changing how your body uses energy from food.

Almost 1 million Australian adults had type 2 diabetes in 2018 (1), and the number continues to grow. Here's how the keto diet affects those with type 2 diabetes, based on its benefits and recent research.

What is the Keto Diet?

The keto diet is a high-fat, low-carb eating style. Created around 100 years ago to treat patients with epilepsy, the keto diet has grown in popularity in recent years for its various health benefits, including weight loss and disease prevention (2).

Most individuals on a keto diet restrict their carb intake to around 10% of their daily calorie intake, swapping grains, fruits, and starchy vegetables for higher-fat and protein-rich options.

Lowering carb intake to minimal amounts often results in a metabolic state called ketosis (3). Under normal conditions, the body burns glucose from carbohydrates as energy. Ketosis occurs when the body switches to burn fat instead of carbs, producing molecules called ketones. 

How the Keto Diet Can Affect Blood Glucose Levels

The keto diet can control blood sugar levels, decreasing the risk of developing type 2 diabetes. Here's how.

Limits Carbohydrate Intake

High carb intake has been associated with blood sugar spikes, which can wreak havoc on insulin levels—because of this, controlling carb intake is essential for people with or at risk of type 2 diabetes.

So, what exactly is the relationship between carbohydrates and blood sugar? When carbs are eaten, the digestive system breaks down the food into simple sugars, which enter the bloodstream. Insulin is then produced, which triggers blood sugar uptake for storage (4).

However, insulin resistance can occur when there are prolonged high-sugar and high-carb consumption (5). This makes your cells stop responding to insulin. Blood sugar levels then remain high long after eating, increasing your chance of developing type 2 diabetes.

The typical keto diet limits carb consumption to less than 50g a day, replacing high-sugar, starchy foods with healthy fats and protein.

Healthy Fats

The keto diet encourages the consumption of healthy fats from sources including avocados, nuts, seeds, and plant oils. The research involving healthy fats has continually been positive, with consumption being linked to lowered cholesterol levels and better control over blood sugar levels (6).

Researchers found that a diet rich in monounsaturated and polyunsaturated fat, like those found in nuts and avocados, improved blood sugar control. In comparison, sugar levels after meals high in carbs and saturated fat were much higher. Eating more healthy fats was also seen to improve insulin sensitivity in those at risk of type 2 diabetes (7).

While the keto diet is rich in healthy fats, overeating red and processed meat can result in too much saturated fat, which isn't the best for us in large quantities (8). To get the most benefits out of the fat you eat, try eating more fatty fish like salmon and mackerel rather than sausages, pepperoni, and steak.

Weight Loss

The importance of maintaining a healthy weight is seen across many chronic conditions, as obesity is associated with inflammation and elevated blood pressure, major risk factors of diseases (9). Likewise, a healthy weight can help improve your body's ability to respond to insulin.

Weight loss can have potent effects on blood sugar levels. Researchers found that even losing 5-10% of body weight can improve blood sugar levels in overweight or obese individuals. In fact, in those who are pre-diabetic, reducing your body weight that much will lower your risk of developing type 2 diabetes by 58% (10)!

The keto diet has long been associated with rapid weight loss. Sugary, high-carb foods are calorie-rich, so cutting them out or limiting the amounts eaten can help shed the kilos. Researchers have also established the importance of high-fat diets in increased satiety, helping you feel fuller for longer (11).

Potential Risks

While cutting out processed sweet treats can help balance blood sugar levels, the traditional keto diet also limits fruits and starchy vegetables. These carb-rich whole foods come packed full of antioxidants, vitamins, and minerals, so cutting out them can result in nutrient deficiencies over time (12).

Because the body's primary fuel is fat instead of carbs, this can elevate the amount of ketones in the blood. When this occurs, the risk of developing diabetic ketoacidosis (DKA) is higher.

DKA is different from ketosis, which is usually harmless. DKA is a serious complication affecting individuals with type 1 diabetes and sometimes those with type 2 diabetes. It occurs when blood sugar levels are elevated, and high amounts of ketones are built up in the body. It can also be triggered by infection or illness (13).

It is recommended to test your blood sugar and ketone levels throughout the day if you are on a keto diet and pre-diabetic. Talking to your doctor is also advised, as DKA is a severe medical condition that will require treatment.

Other Diets That May Offer Benefits

While there is considerable research supporting the keto diet for diabetes management, other research looking into different diets have also been promising.

Some studies have pointed out that a lower-carb way of eating is sufficient for blood sugar control, and complete elimination of carbs is not needed (14). Others have suggested a vegetarian or vegetarian keto diet can help lower inflammation and improve insulin sensitivity (15).

The Bottom Line

The keto diet is a low-carb eating style that can help control blood sugar levels and improve insulin sensitivity. This can decrease your risk of developing type 2 diabetes or can help you manage it.