Low calorie liquid diets and type 2 diabetes remission

By Alexander Williams
17th September 2018
In Depth, Opinion
 
4969

Recently, there has been much talk about the idea of remission of type 2 diabetes. The notion that the disease, once thought to be a life sentence, can in fact be placed into remission, or even reversed, offers much hope.

With 3.8 million people suffering from diabetes (nine tenths of those with type 2 diabetes), costing the NHS an estimated £9 billion per year, NHS chiefs are very interested in diabetes remission and reversal. Though various approaches have been proposed, NHS attention has recently turned to combatting diabetes using a diet of low calorie, low fat, commercial meal replacement shakes and soups, to a total of around 800-850 kcal per day.

Research leading to this development

Interest in this area comes mainly from the results of the DiRECT study, led by Professor Roy Taylor at Newcastle University. His group used an intervention featuring low calorie meal replacements for 3-5 months, followed by gradual reintroduction of regular food.

Prof Taylor’s group found that 46 per cent of the participants in the intervention group had placed their diabetes in remission at 12 months.

Professor Jonathan Valabhji, National Clinical Director for Obesity and Diabetes at NHS England, had this to say about the study:

“The trial involved 300 people, of those in the intervention arm a staggering almost 50 per cent their diabetes went into remission…
Their blood glucose levels fell into the non-diabetic range…
That excites us. The beauty of the research is that it was implemented in GP surgeries. It wasn’t hugely expensive”

Type 2 diabetes is generally associated with obesity and the study indeed reported that higher rates of diabetes remission were achieved in the groups losing more weight, with the highest rate of remission (86%) in those losing over 15 kg.

Possible imperfections

The DiRECT study has done a very important job in providing evidence for the possibility of type 2 diabetes remission and reversal, and this type of intervention may soon be implemented in NHS strategy. While calorie restriction can be an effective strategy for losing weight in the short term for some people, there are perhaps some caveats to consider.

First, long-term caloric restriction can lead to a reduction in resting metabolic rate (RMR) which is the number of calories the body burns in a day, at rest. This can cause people to feel cold, tired and hungry, as the body does not expend as much energy on its normal processes when reducing its RMR. There is evidence that RMR can remain lowered even six years after initial weight loss by caloric restriction. The negative effects of this metabolic adaptation could reduce the sustainability of these types of interventions and so may be responsible for the considerable dropout rate.

Second, although overweight and obesity are associated with type 2 diabetes, the existence of a causal relationship between weight and diabetes is heavily disputed. Indeed, there are many obese people that do not have diabetes and many people of normal BMI that do. The DiRECT study’s co-primary outcomes were “weight loss of 15 kg or more, and remission of diabetes”, meaning a large focus was placed on considerable weight loss (of an absolute value, rather than one proportional to each individual). While many people with type 2 diabetes may benefit from weight loss, some may not and this focus may lead to more causal metabolic variables being overlooked.

Third, the nutrient composition of the meal replacements used in this intervention, and in similar meal replacement products, are perhaps not optimal for improving metabolic health. For example, one serving of Optifast vanilla shake contains 18.5 grams of sugar – a nutrient that is not essential for anyone, much less so for people with diabetes.

Can we do even better?

While caloric restriction via a diet of meal replacement shakes and soups may work for some people in the short term, it may not be effective or tolerable for others and may be missing out on some key points. For instance, it’s possible that what we eat, rather than how much of it, may be more important for metabolic health.

Results from the Low Carb Program, amongst those of other programmes, show that type 2 diabetes can be placed in remission by focusing on restriction of carbohydrate rather than calories. It is therefore important that this option is at least made known to those with type 2 diabetes. While very low calorie diets are not sustainable in the long-term, as they’re unsuitable for weight maintenance, carbohydrate restriction offers a strategy that can be used for both weight loss and maintenance, without a focus on calories.

If a person does wish to use caloric restriction as a method of weight loss and diabetes remission, it could be important to consider that this can be done using a hypocaloric diet of real foods, without the need for processed meal replacements. So, while the possibility of diabetes remission or reversal offered by these interventions is undoubtedly a message of hope, focusing solely on low calorie shakes may be missing the bigger picture of metabolic health.

What do you think?