VLED and formula LED in the management of type 2 diabetes: defining the clinical need and research requirements.

Abstract

It has been known for many years that substantial weight loss, achieved by bariatric surgery or non-surgical means can mean normalize glucose tolerance. Recent randomized controlled trial evidence indicates that >15 kg weight loss is necessary, to this and it may lead to near normalization (doubling) of life expectancy. Less than 5% of patients achieve this through even the best, evidence-based medical weight management programme (Counterweight http://www.counterweight.org). A weight loss of >15 kg is easily achievable by 8 weeks very low-energy diet (VLED)/LELD (Low energy Liquid-formula Diet) in compliant patients, with little difference between 400 and 800 kcal day(-1) , but weight maintenance after VLED has until recently been so poor that VLED is not, at present, recommended in clinical guidelines. However, mean weight loss close to >15 kg can be maintained 18-24 months using a variety of maintenance strategies. These include a structured reintroduction of foods linked to an education programme with behavioural strategies, intermittent VLED use and prescribable anti-obesity drugs (dexfenfluramine, orlistat, sibutramine). Most of these studies have been in non-diabetic subjects. A new 'curative' paradigm in type 2 diabetes mellitus management, aiming to normalize glucose tolerance and health risks by achieving and maintaining >15 kg loss, as soon as possible after diagnosis, should be highly acceptable to patients, generating many additional Quality Adjusted Life Years (QALYs). It is likely to be highly cost-effective by avoiding the current recommended, mainly palliative, model, using polypharmacy which provides an overall risk reduction of only 5-10%. Clinical trials are on-going to establish the feasibility of delivering formula (LELD) and a maintenance programme to large numbers of patients within routine primary care. There is urgent need, to run similar studies in diabetic patients. New approaches to long-term (lifelong) maintenance of weight loss and a non-diabetic state may include anti-obesity drugs.