Type 2 diabetes mellitus has traditionally been regarded as a progressive, irreversible condition characterised by insulin resistance followed by gradual loss of pancreatic function. However, research carried out in the last decade has indicated that the physiological derangements that cause type 2 diabetes can be corrected and that type 2 diabetes can be essentially be put into remission.
The Association of British Clinical Diabetologists (2019) defines ‘remission’ as being able to control blood glucose levels (fasting plasma glucose less than 7mmol/L or HbA1c of less than 6.5%) without any medications.
How?
Most clinical studies in this regard have indicated that around half of people who are within the first 10 years since initial diagnosis can cease all diabetic medicines and achieve normal blood glucose control when a 15kg weight loss is achieved. For persons who have been diagnosed as diabetic for longer than 10 years, remission appears much less likely.
Pathophysiology of type 2 diabetes and remission
It is believed that type 2 diabetes is predominantly caused by excessive food intake, leading to fat accumulation, specifically in the liver and pancreas. In turn, this causes the body’s cells to be less sensitive to insulin (insulin resistance). Besides, accumulation of fat in the pancreas disrupts beta cell function (the cells that make insulin), resulting in less insulin produced. Consequently, the body is no longer able to maintain blood sugar within normal range, and diabetes develops.
It was initially noticed that a significant percentage of obese persons with type 2 diabetes who underwent weight loss surgery were able to stop all diabetes medication following the substantial weight loss that occurred after surgery. Then in 2011, the Counterpoint study at Newcastle University demonstrated that in persons with type 2 diabetes who were put on an eight-week very low-calorie diet (resulting in an average body weight loss of 15kg), liver and pancreatic fat levels dropped to normal levels, and subsequently pancreatic beta cell function improved.
This was followed by the larger Diabetes Remission Clinical Trial published in 2018 and involving over 300 individuals. After 12 months, almost half of participants who were put on the low-calorie diet achieved remission and were able to stop all anti-diabetic medications.
The best diet for each person will be the one that the person is able to stick to
The greater the amount of weight lost, the higher the chance of achieving remission. For example, among those who lost five to 10kg, ‘just’ 36 per cent achieved remission. On the other hand, among those who lost 15kg or more, a remarkable 86 per cent achieved remission.
These results clearly indicate that in type 2 diabetes, pancreatic beta cells do not die off as previously assumed, but rather, they lose the ability to secrete insulin. More impressively, the studies mentioned showed that beta cell recovery is possible and can be maintained – if the weight lost is not regained.
Which diet is best?
This is a highly debated topic, and currently low-carbohydrate diets and intermittent fasting regimens are in vogue. Though one might assume that low-carbohydrate diets are inherently superior for diabetes since carbohydrates are the source of blood sugar, studies comparing different diets have repeatedly shown that one is not superior to the other. In other words, what counts is the number of calories consumed, and not the macronutrient composition of the diet (e.g. Johnston et al., 2014 & Sainsbury et al., 2018).
What is key is dietary adherence – in other words, the best diet for each person will be the one that the person is able to stick to. Some people are more comfortable with a low-fat diet, while others may find low-carbohydrate diets easier. At the end of the day, however, reducing 500 calories per day from the usual intake results in the same amount of weight lost – irrespective of how that reduction was achieved.
Whatever the type of diet followed, it is important to ensure that overall dietary balance is maintained – for example, though a person may ‘enjoy’ a low-carbohydrate diet that is low in calories but high in saturated fat, this would endanger cardiovascular health, so would not be recommended.
Weight maintenance
Maintenance of weight lost is typically much harder than achieving the initial weight loss. Support from family and friends has a critical role in avoiding weight regain, as eating is a social activity.
Regular support from healthcare professionals, including registered dietitians, is also extremely helpful to keep a person on track and to provide strategies during periods when a person may be experiencing low motivation or risk of relapse.
Two other cornerstones of weight management appear to be regular physical activity and regular self-weighing.
Manuel Attard is a registered dietitian and nutritionist.