Surgical operations, such as gastric banding and gastric bypass, are potential solutions because they lead to dramatic weight loss, which can put Type 2 diabetes into remission for up to 80% of patients. But these treatments are expensive, invasive and carry a risk of surgical complications, which mean they can only be offered as a last resort.
What do we know already about low-calorie diets?
In 2011, a Diabetes UK research trial at Newcastle University tested a low-calorie diet in 11 people with Type 2 diabetes, which helped us to understand how Type 2 diabetes can be put into remission.
After the 8-week diet, volunteers had reduced the amount of fat in their liver and pancreas. This helped to restore their insulin production and put their Type 2 diabetes into remission. Three months later, some had put weight back on, but most still had normal blood glucose control.
This study was only a first step. It was designed to tell us about the underlying biology of Type 2 diabetes, and it followed the participants for only three months.
Another study, published in 2016, confirmed these findings and showed (in 30 people) that Type 2 diabetes could be kept in remission 6 months after the low-calorie diet was completed. It also suggested that the diet was effective in people that had had Type 2 diabetes for up to 10 years.
Both of these studies were very small, and were carried out in a research environment. We don't yet understand the long-term effects of these diets, or how a low-calorie diet might be used to bring about and maintain Type 2 diabetes remission in a real-life setting, as part of routine GP care.
What is the aim of the current research?
The DiRECT (Diabetes Remission Clinical Trial) study aims to find out if intensive weight control can bring about the remission of Type 2 diabetes and be maintained long-term through routine NHS care.
The trial will compare the long-term effects of a low-calorie diet and weight management programme to bsst available care for Type 2 diabetes.
What will the research involve?
Participants receiving best-available care will get weight loss support in accordance with the latest clinical guidelines, but won't receive the low-calorie diet.
The researchers will test metabolisms and measure fat deposits inside the body, to reveal exactly how major weight loss can put Type 2 diabetes into remission. They'll also carry out psychological assessments with the participants and healthcare professionals taking part in the study, to work out how this approach to weight management might form part of routine GP care.
Where is the research taking place?
This study will take place at around 30 GP practices in Scotland and Tyneside. The research will be carried out and the data analysed by researchers at the University of Glasgow and at Newcastle University.
Who can take part?
Only people invited to take part by their GP practice can get involved in this study. Recruitment is only taking place at selected GP practices in Scotland and Tyneside. Individual patients are not being recruited.
When will results be available?
This study will last until October 2018, and the overall results will be released once all of the data has been analysed. We'll report the results in Diabetes UK publications and on the website.
The low-calorie diet
What will the diet used consist of?
The diet used in DiRECT will last for between 8 and 20 weeks and provide around 800 calories a day. It will consist of four diet soups or shakes per day, providing all essential vitamins and minerals and lots of fluids.
Will the diet cure Type 2 diabetes?
The diet being studied isn't a 'quick fix' for Type 2 diabetes. It should help people taking part in the study to lose weight – specifically, the fat in and around their liver and pancreas. This should, in turn, help to put their Type 2 diabetes into remission.
It's likely that some people who take part in the research will find the diet challenging, and every participant will have to work hard to keep weight off in the long-term to maintain Type 2 diabetes remission.
Is the diet used in this research available now?
Low-calorie diet foods are not available on prescription from the NHS. They're marketed by a range of private companies, but can be expensive and come with limited evidence of long-term benefit.
This research is the only way to tell if weight management using a low-calorie diet is practical and more effective than the current best-available treatments for Type 2 diabetes.
Should people with Type 2 diabetes follow the diet used in this research?
Until we have evidence that a low-calorie diet is more effective than the current best-available treatment, Diabetes UK recommend that people with Type 2 diabetes only attempt to lose weight in this way after they have spoken to their GP.
We're confident that DiRECT will answer important questions and give the NHS enough evidence to decide whether low-calorie diets should be offered as a routine treatment option. People with diabetes should always consult their GP before making changes to the way that they manage their condition.
What diet does Diabetes UK recommend for people with Type 2?
Diabetes UK recommends that people with Type 2 diabetes eat a healthy, balanced diet that is low in sugar, salt and fat and includes plenty of fruits and vegetables. For information on living a healthy lifestyle and eating well with Type 2 diabetes please see our guide to diabetes.