March 6, 2019

expert reaction to study looking at weight loss and type 2 diabetes

Research published in the Lancet Diabetes & Endocrinology demonstrates sustained remission of more than a third of people with type 2 diabetes. This remission was linked to sustained weight loss.

Dr Nicola Guess, Lecturer in Nutritional Sciences, King’s College London, said:

“This is a randomised control trial which is the strongest type of study design.  It is also a large sample size and benefits from a long follow up period.  These factors mean that the data from this trial are as robust and reliable.  This study demonstrates the importance of marked weight loss (>15kg) and the maintenance of that weight loss to ensure remission of type 2 diabetes is sustained.  This research was carried out in primary care and is therefore a good model of what can be achieved within GP Practices nationwide.

“However, maintenance of weight loss is not the whole story: type 2 diabetes returned in a minority of people (16%) who kept off 15kg or more for 2 years.  Further research is needed to help us understand why this is.  It is possible that these people had type 2 diabetes for longer before losing weight, or perhaps there might be dietary or genetic factors which contributed to the return of type 2 diabetes.  The DiRECT study group have included sophisticated measures of the underlying factors which cause diabetes including pancreatic and liver fat which will provide further insight into why type 2 diabetes returned in some people and not others despite losing the same amount of weight.”

Prof Tom Sanders, Professor emeritus of Nutrition and Dietetics, King’s College London, said:

“This is a well controlled study in obese patients with type 2 diabetes that initially used a low calorie formula diet (just above 800 kcal/d) exclusively for the first three months and then a structured diet using normal food to support weight maintenance.  This resulted in rapid weight loss and a concern has been that individuals ‘yo-yo’ back to their original weight when they stop the diet.

“This study found that weight loss was maintained at 2 years in most patients.  It shows a clear dose response relationship between the amount of weight loss and remission of diabetes.  The authors conclude that about 1 in 3 obese people with diabetes 2 given the advice were able to control their type 2 diabetes in terms of controlling their blood sugar levels reducing the need for medication.  However, although there was a small fall in blood pressure (3.4 mm Hg) in the weight loss group, there was no effect of weight loss on blood cholesterol levels (their blood cholesterol levels were low) probably because both groups were still taking statins.

“A limitation of the study is that is was conducted in patients under 65 who had been diagnosed within the last six years and were still producing normal amounts of insulin.  Obese patients with type 2 diabetes usually produce relatively high amounts of insulin but are resistant to its action.  These are the patients mostly likely to benefit from weight loss as well as increased physical activity because this helps reverse resistance to insulin.

“Many people develop diabetes because the capacity to produce insulin falls with increasing age making blood sugar levels harder to control.  Furthermore, women who develop gestational diabetes in pregnancy or who have polycystic ovary syndrome are also more likely to develop type 2 diabetes in the long-term.  Consequently, It is important not to stigmatise people with type 2 diabetes as many patients with type 2 diabetes are average weight and would not necessarily benefit from weight loss.”

‘Durability of a primary care-led weight-management intervention for remission of type 2 diabetes: 2-year results of the DiRECT open-label, cluster-randomised trial’ by Michael E J Lean et al. was published in The Lancet Diabetes & Endocrinology at 11:35am UK time on Wednesday 6 March 2019.

Declared interests

Dr Nicola Guess: “Grant funding from Diabetes UK MRC, diabetes research and wellness foundation, Winston Churchill memorial trust and the American overseas dietetic association.  Does research into low carbohydrate diets.”

Prof Tom Sanders: “Honorary Nutritional Director of HEART UK.  Scientific Governor of the British Nutrition Foundation.  He is now emeritus but when he was doing research at King’s College London, the following applied: Tom does not hold any grants or have any consultancies with companies involved in the production or marketing of sugar-sweetened drinks.  In reference to previous funding to Tom’s institution: £4.5 million was donated to King’s College London by Tate & Lyle in 2006; this funding finished in 2011.  This money was given to the College and was in recognition of the discovery of the artificial sweetener sucralose by Prof Hough at the Queen Elizabeth College (QEC), which merged with King’s College London.  The Tate & Lyle grant paid for the Clinical Research Centre at St Thomas’ that is run by the Guy’s & St Thomas’ Trust, it was not used to fund research on sugar.  Tate & Lyle sold their sugar interests to American Sugar so the brand Tate & Lyle still exists but it is no longer linked to the company Tate & Lyle PLC, which gave the money to King’s College London in 2006.  Tom also used to work for Ajinomoto on aspartame about 8 years ago.  Tom was a member of the FAO/WHO Joint Expert Committee that recommended that trans fatty acids be removed from the human food chain.  Tom has previously acted as a member of the Global Dairy Platform Scientific Advisory Panel and Tom is a member of the Programme Advisory Committee of the Malaysian Palm Oil Board.  In the past Tom has acted as a consultant to Archer Daniel Midland Company and received honoraria for meetings sponsored by Unilever PLC.  Tom’s research on fats was funded by Public Health England/Food Standards Agency.”