Published in the Lancet, the DiRECT study found that half of patients given a strict low-calorie diet regime reverted to a non-diabetic state after one year.
The researchers, from Glasgow and Newcastle universities, said the findings could ‘revolutionise’ diabetes care, and lend support to ‘widespread use’ of the intervention throughout primary care.
Previous research by the team has shown that type 2 diabetes is caused by excess fat within the liver and pancreas. The current study shows for the first time that this can be reduced through a very low calorie diet delivered as part of routine primary care.
‘Substantial weight loss results in reduced fat inside the liver and pancreas, allowing these organs to return to normal function,’ said lead author Professor Roy Taylor.
‘What we’re seeing from DiRECT is that losing weight isn’t just linked to better management of type 2 diabetes: significant weight loss could actually result in lasting remission.’
Almost 300 adults aged 20-65 – all of whom had been diagnosed with diabetes in the past six years –were included in the study. Anti-diabetic and BP-lowering drugs were all stopped at the start of the programme.
Half were placed on a weight management programme, which began with a diet replacement phase consisting of a very low calorie formula diet for three to five months. Participants ate 825-853 calories a day.
This was followed by stepped food reintroduction after two to eight weeks and on-going support for weight loss maintenance, including cognitive behavioural therapy with strategies to increase physical activity.
Participants in the intervention group lost an average of 10kg after one year. Nearly half (46%) achieved diabetes remission, compared to just 6% of those in the control group, who were treated by their GP under best practice guidelines.
Remission was defined as achievement of a glycated HbA1c level of less than 6.5% at 12 months, in absence of all medications.
Dropout rate was 21% among those on the intervention programme, which the researchers said was mainly due to social reasons such as bereavement, loss of job or moving house.
Type 2 diabetes affects almost one in 10 adults in the UK, costing the NHS £14bn a year.
Professor Taylor said: ‘Rather than addressing the root cause, management guidelines for type 2 diabetes focus on reducing blood sugar levels through drug treatments. Diet and lifestyle are touched upon but diabetes remission by cutting calories is rarely discussed.
‘A major difference from other studies is that we advised a period of dietary weight loss with no increase in physical activity, but during the long-term follow up increased daily activity is important.
‘Our findings suggest that the very large weight losses targeted by bariatric surgery are not essential to reverse the underlying processes which cause type 2 diabetes.'
Dr Elizabeth Robertson, director of research at Diabetes UK, said: ‘These first year findings of DiRECT demonstrate the potential to transform the lives of millions of people. We’re very encouraged by these initial results, and the building of robust evidence that remission could be achievable for some people.’