Helpful or just hype? A look at the Ketogenic Diet

Friday, 4 January 2019

With the ringing in of a New Year, comes a flood of new diet and exercise plans. The ketogenic diet has risen in popularity as a way for people with diabetes to lose weight and manage blood glucose levels (BGLs), so let’s have a look at the evidence behind this way of eating.

The basics – What exactly is a ketogenic diet?

Some diets focus on cutting out foods, while some focus on when you’re allowed to eat. Other diets however, focus on macronutrients. Macronutrients are the three main parts of food that provide energy: carbohydrates, proteins and fats.

The ketogenic diet was originally developed in the 1920s as a treatment for children with epilepsy who suffered from severe seizures. The diet is very low in carbohydrates (no more than 20-50g per day) and high in fats. Without enough carbs for energy, the body breaks down fats (either from food or body fat) to produce ketones, which some parts of the body can then use for energy.

While some parts of our body can use ketones, other parts (such as the brain and red blood cells) need glucose each day to function. Because of this, the body makes glucose by breaking down proteins (either from food or muscles).

What foods are included in a ketogenic diet?

Foods rich in protein and fat feature heavily. These include meats, fish, eggs, cheese, bacon, oils, butter, cream, avocado and nuts. Some low carb vegetables might also make an appearance.

Meats and animals fats such as butter, lard, cream, coconut and palm oils are sources of saturated fat. Saturated fat can have a negative impact on cholesterol levels and heart health, as well as increasing insulin resistance. Try to swap sources of saturated fat for unsaturated fats like avocado, olive oil and fish.

Since carbohydrates are restricted on the ketogenic diet, foods naturally high in carbs such as fruit, potato, breads, pasta rice, beans, milk and yoghurt are mostly cut out. These foods are found in many of the core food groups recommended in The Australian Guide to Healthy Eating as they provide a range of important nutrients such as fibre, B vitamins and calcium. It can be hard to get all the nutrients you need on a ketogenic diet, without supplements.

The diabetes link – are carbs really the enemy?

When it comes to diabetes, carbohydrates are often the first thing that comes to mind. This is because when we digest carbs, they get broken down into sugar (glucose) and directly impact BGLs. Considering this, you’d be forgiven for thinking that restricting carbs (for example, by following a ketogenic diet) might help stabilise BGLs.

Some studies have shown that low carb diets can be safe and provide some benefits to people with diabetes in the short term, however there isn’t strong evidence that these benefits can be maintained longer than six months.

One concern of people with diabetes following a ketogenic diet is the increased risk of hypoglycaemia, particularly for those who manage their diabetes using insulin or certain medications. There are also some people that a ketogenic diet might not be safe for, including children, breastfeeding or pregnant women, those at risk of malnutrition, people with kidney or liver failure or those with a history of disordered eating. It’s always important to get support from your diabetes team with any new eating plan you’re thinking of trying, to make sure it’s right for you.

A note on fibre – the underrated diabetes super nutrient!

Less than one in three Australian adults are getting enough fibre each day. Fibre has loads of benefits, particularly for people with diabetes, including:

  • Helps keep you full
  • Helps keep BGLs more stable
  • Can help lower cholesterol levels
  • Helps keep you regular
  • Reduces the risk of bowel cancer
  • Can help fuel the beneficial bacteria in the gut and promote balance in the digestive system

Most of our fibre comes from carbohydrate plant foods, so people following a ketogenic diet may find it hard to get enough.

The take home

Any way of eating that involves a lot of restriction increases the risk of disordered eating and may result in poorer mental health due to body dissatisfaction, weight yo-yoing and increased weight in the long term. The best way of eating is the one that helps you feel your best, is enjoyable and works for you.

People with diabetes have the same nutritional needs as people without diabetes and no foods need to be cut out to manage diabetes well. When it comes to carbohydrates, your dietitian can help you find the type, amount and time of day to eat carbs that suits you and your lifestyle.

If you’re thinking of trying out of ketogenic diet, then it’s important to get the support of your diabetes team to help you do this safely.


Caitlin Jamieson (APD)

Join our community of over 45,000 people living with diabetes