The ketogenic diet involves eating high fat, high protein and low carbohydrate. The diet forces to the body to use fat to provide energy.

By replacing carbohydrate with fat as the body’s main energy source, more ketones are produced in the blood, a state which is known as ketosis.

Research shows a ketogenic diet could be beneficial for people with diabetes, as it can decrease blood glucose levels, but there are concerns over the long-term safety of the diet.

What is a ketogenic diet?

The ketogenic diet was first designed by Dr. Russell Wilder in 1924 to treat epileptic seizures. The diet has since been adapted to achieve weight loss.

Ketosis, as induced by the diet, is the process by which the body breaks down body fat to produce ketones, which are an alternative energy source to glucose.

A medical ketogenic diet typically involves eating a 4:1 weight ratio – four parts energy come from fat, with the one part derived from a combination of carbohydrate and protein.

Low-carb diets are generally found to be successful in achieving weight loss, but the ketogenic diet can be restricting.

As a result, you may need to eat 40g or less of carbohydrate per day, with the majority of your energy coming through your fat intake instead of carbs.

Can people with diabetes eat a ketogenic diet?

People with diabetes should consult their doctor or diabetes specialist before starting a ketogenic diet, as it will need to be carried out safely.

Reduced blood glucose levels and decreased insulin resistance have been reported through a ketogenic diet, which can be beneficial for people with type 2 diabetes.

However, overly high ketone levels can lead to diabetic ketoacidosis (DKA), a dangerous short-term complication. DKA can affect people with type 1 diabetes when their blood glucose levels are too high, but it is also possible in type 2 diabetes.

If you have type 1 diabetes and wish to follow a ketogenic diet, you should speak with your doctor so they can advise you on the possible risks and what precautions to take.

The prolonged periods of ketosis that come from a ketogenic diet have come under scrutiny from the medical profession. However, no studies have categorically stated that the ketogenic diet is unsafe in the long-term.

Anyone with diabetes who embarks on a ketogenic diet is advised to keep hydrated and may be told to consider regularly testing their ketone levels.

What can I eat on a ketogenic diet?

With high-carb foods such as pasta, bread, grains, sugar and starchy vegetables excluded from the ketogenic diet, you will need to focus on eating healthy sources of fat instead, such as:

  • Fish – salmon, tuna and shellfish
  • Nuts – macadamias, almonds and walnuts
  • Dairy – eggs, cheese, cream and yoghurt
  • Butter – including coconut, almond and peanut butter
  • Oils – coconut, olive, red palm
  • Avacado

Are there any side effects from a ketogenic diet?

There are a number of reported side effects from people on a ketogenic diet. These include:

  • Constipation
  • Headaches
  • Insomnia
  • Constipation or diarrhoea
  • Tiredness and feeling dizzy
  • High levels of calcium in the urine
  • Kidney stones
  • Irregular periods

Some of these side effects may become resolved after a number of days. If side effects are serious or more persistent than this, discontinue the diet and speak to your doctor.

Some people may also find the restrictions regarding to the diet are too hard to stick to in the long-term.