Type 2 diabetes effects almost one in ten people in the UK. Current guidelines for management of type 2 diabetes focus heavily upon drug treatments to help reduce blood glucose levels and reduce the risks associated with the disease. With diabetes taking up to 10% of the total NHS budget, alternative lifestyle therapies have never been in more demand.
90% of type 2 diabetes sufferers are overweight. Particularly the accumulation of fat in the liver and pancreas effects how the body is able to regulate its blood glucose levels. Therefore, it is logical to suggest weight loss as a primary treatment could help to dramatically improve the condition.
It has been known for some time by inducing a 600-700kcal negative energy balance (i.e. use more calories than you need) per day liver insulin resistance and fat content has normalised. What has been unknown is whether such a treatment is a practical solution in primary care.
The DIRECT study (Diabetes Remission Clinical Trial) aimed to assess whether effective weight management, delivered in the primary care setting, could produce sustained remission of type 2 diabetes.
Versions of the diet have been gathering popularity in mainstream media and has been endorsed by several celebrities including Michael Mosley who released his blood sugar diet.
The DIRECT Study
The study group contacted 49 GP surgeries for recruitment in the study. The study was to run for 12 months with regular monitoring of participants. The trial measured weight loss, HbA1c (average blood glucose levels), blood pressure, quality of life, blood fats and physical activity.
Eligibility was defined as patients between 20-65 years old, had been diagnosed with type 2 diabetes within the previous 6 years and had a body mass index of 27-45kg/m2.
Exclusion criteria were any patients using insulin, a HbA1c of over 108mmol/mol, weight loss of more than 5kg within the previous 6months, significant kidney and heart damage, substance abuse, known cancer, history of an eating disorder or purging behaviour, pregnancy, current treatment with anti obesity drugs, hospital admissions for depression, learning difficulties, or participation in another clinical research trial.
At the end of the 12 month trial 2 groups consisting of 148 participants remained. Group one known as the intervention group, followed an initial total diet replacement phase using low energy formulas of around 800kcal/day made up of 59% carbohydrate, 13% fat and 26% protein for 3 months (this was extendable to 5 months if participants wished). This was followed by a food reintroduction (50% carbohydrate, 35% total fat and 15% protein) of 2-8 weeks and an ongoing structured programme with monthly visits for long term weight loss maintenance. All oral anti diabetic and anti hypertensive medications were discontinued on day one of the weight management programme. This allowed for any changes in blood glucose readings or blood pressure to be attributable to the diet. Participants were encouraged to continue to their usual physical activities but were not asked to increase this.
The second group, known as the control, group continued as normal with no intervention in anyway. In research, this allows the intervention group to have something to compare against should any changes be seen following the diet.
At 12 months the study recorded weight loss of 15kg (this was deemed significant for the study purposes) or more in 36 participants in the intervention group and no participants in the control group. They recorded diabetes remission in 68 participants in the intervention group and 6 participants in the control group.
Average body weight fell by 10kg in the intervention group and by 1kg in the control group.
Participants in the intervention group who engaged with the intervention, weight fell sharply during the total diet replacement phase, by 14.5kg, followed by small increases during the food reintroduction phase. Patients who completed the total diet replacement phase had greater weight loss and those who completed the food reintroduction phase saw less weight gain, than did patients who started, but did not complete, each phase.
For all participants, diabetes remission was not achieved by any participant who did not lose weight at 12 months. The more weight lost, the higher rate of remission which was achieved.
At 12 months 109 of the 148 participants in the intervention group were taking no anti diabetic medications compared with 27 of 148 participants in the control group. Also, at 12 months the number of participants being prescribed medications for other non diabetes conditions was lower in the intervention group than the control group.
We have known for a while the best treatment for type 2 diabetes in the vast majority of people is weight loss. There are those few unfortunate individuals who develop the disease despite being a normal weight but these people tend to be in their later years and have little chance of developing the long term complications of type 2 diabetes.
The study is certainly interesting. Being a dietitian it is fantastic to see the importance of lifestyle interventions coming to the forefront as potential treatments for lifestyle related diseases. In a model of healthcare which is primarily focused on drug therapy it is quite refreshing for a study to address the underlying cause of the condition.
For me the amount of weight loss being directly correlated to the number of remission cases seen really brought home the need to for us health care professionals to encourage patients to act.
I think it is unfortunate however how the data presented here has been represented in the media and even some healthcare professionals who think the 800kcal intervention is some miracle solution.
Reading the study, what became overly abundant to me was 800kcal is not some magic number of calories required to induce diabetes remission. Instead, it is the weight loss which is key. This is particularly highlighted by the fact 6 participants in the control group also managed to achieve remission. Of the 6, all of these achieved significant weight loss. Those who did not achieve weight loss, did not achieve remission.
In fairness to the study, they do not quote 800kcal as the reason for diabetes remission cases. Instead, they too attribute it to the weight loss.
I wonder then whether following a less intensive lifestyle intervention focused on achieving similar weight loss would elicit similar results. My concerns with the 800kcal diet phase was this was achieved with meal replacements with frequent professional follow up. This would unlikely be available to patients in the real world setting and a total diet replacement for 3 months may be difficult to sustain. Instead, I think it may be more conducive to focus on a calorie controlled diet using real food.
Some versions of the 800kcal diet inform the reader carbohydrates such as bread, pasta, rice, potatoes are the cause of their ailments and advise the reader to abstain from such foods. However, as mentioned above, the diet through all phases had a carbohydrate content of 50% or above. Therefore, if using this study as our marker, it is clear it is total energy intake and not the composition of food which is important for diabetes control. In fact, the 800kcal meal replacement phase was very low fat (13%) compared to reasonably high carbohydrate (59%).
In reality I wouldn’t draw such abrupt conclusions as the study size was small. However, most historical research that has focused on long term weight loss, shows no advantages of following any particular diet over another. It is the total energy intake which is important.
There are also concerns about rapid weight loss inducing gallbladder issues such as gallstones. Although not overly common, 2 participants in the study did develop such issues.
Those reading this who fall within the exclusion criteria because they take insulin or have a high HbA1c, I would also encourage you think abut addressing your diabetes control. Granted, once insulin is commenced, it demonstrates a certain progression of the disease. This does not mean all is lost. There is no better time to start doing something than now and significant improvements in your diabetes can still be made.
It is worth noting remission is not the same as cured. If you manage to achieve remission of your type 2 diabetes it is still wise to attend a yearly assessment with your practice nurse.
Perhaps future studies can encourage a shift in healthcare funding to consider a move towards a more preventive model of care. With healthcare budgets consistently stretched it is always difficult to prevent a fire when you are putting one out. This study does begin to identify how lifestyle interventions can lead to cost savings as medications are discontinued.
My parting words would be if you are wanting to make a difference to your diabetes management, long term sustainable weight loss is the key.