How do the different dietary approaches for type 2 diabetes compare?

Diabetes is a major public health problem. Each day, 280 Australians will be diagnosed with diabetes with the total number of people in this country with either diabetes or a condition of pre-diabetes standing now at a staggering 3.2 million. Type 2 diabetes is by far the most common form of diabetes and is leading the world-wide explosion in this disease.

There is much we know about how type 2 diabetes can be prevented by lifestyle changes that focus on modest weight loss, eating more foods high in fibre, eating less foods high in saturated fat and getting more active.

What is less clear is what type of dietary pattern is optimal for controlling blood sugar levels in someone already with type 2 diabetes. There have been many clinical trials looking at different dietary approaches to managing type 2 diabetes which include:

•     Low-carbohydrate
•     Vegetarian
•     Vegan
•     Low glycaemic index (GI)
•     High fibre
•     High protein
•     Mediterranean

These different dietary approaches do not exist in isolation and there is a large degree of commonality between them – particularly their focus on eating more unprocessed foods. For someone with diabetes, it can be confusing to work out what is the best way to eat with so much conflicting information. So scientists have evaluated the different dietary approaches to see what type of pattern appears to be the most effective.

From a review of 20 randomised clinical trials, the four dietary patterns that appeared to offer the most benefit were a low-carbohydrate, low-GI, Mediterranean, and high protein diet.

The dietary pattern with the greatest effect overall was the Mediterranean diet. This is hardly surprising considering the wealth of research showing that a Mediterranean diet pattern has many positive health benefits.

The key aspects of a Mediterranean diet includes plenty of olive oil, legumes, unrefined cereals, fruits, and vegetables, as well as fish, moderate consumption of dairy products (mostly as cheese and yoghurt) and wine, and low consumption of meat and meat products.

What it all means

The results from this review of dietary patterns for type 2 diabetes are not to be taken as an endorsement for one particular approach that should be followed by everyone. Even the authors were quick to acknowledge that dietary behaviours and choices are personal so dietary recommendations should be individualised rather than to use a one-size-fits-all approach. Take some of the key themes of eating a mostly plant-based diet, high in fibre and low in processed foods, as a guideline that all people with type 2 diabetes can work around.