During the 8-week very-low-calorie diet, 50% of people with long-duration type 2 diabetes and 87% with short duration diabetes returned to non-diabetic fasting glucose levels despite withdrawal of all anti-diabetic therapies.” Take a moment to pick your chin up off the floor, and read that again. In 1976, Dr Robert Linn, an American osteopath, himself a “snacker” weighing 235 lb, discovered and exploited the liquid protein regimen, “The Last Chance Diet”, making $40 million in the process. Linn opened clinics “with thick carpets and thin nurses”, attracting the attention of celebrities such as Jacqueline Onassis, but unfortunately the diet contributed to the sudden deaths of a large number of individuals. The cause of the problem was reportedly the quality of the protein utilised within the regimen; basically collagen scooped up from the slaughterhouse floor. So the bad reputation of very-low-calorie diets (VLCDs) was born.
However, a gradual rehabilitation of the concept of VLCDs is now gaining momentum, and the paper by Steven and Taylor, summarised alongside, adds substantially to their renewed acceptance. The diets’ ability to induce weight loss has been well proven, and now with high-quality protein utilisation their safety is assured, but this article provides evidence that they also induce a reduction in risk factors and dramatic improvements in the comorbidities of obesity. Their ability to improve or eliminate sleep apnoea has previously been shown, and studies have been carried out in short-duration diabetes (Lim et al, 2011).
The new evidence that this study reports on is the effect of VLCDs in more severe, long-duration diabetes, and the effect is dramatic. Participants stopped all glucose-lowering agents prior to the study, even if they were on insulin, and then initiated the diet of under 700 calories plus non-starchy vegetables with the results stated above. As if that wasn’t enough, in the long-duration group blood pressure improved from an average of 160/90 mmHg to 133/80 mmHg, total cholesterol from 4.8 to 3.7 mmol/L, and triglycerides from 2.2 to 1.0 mmol/L indicating an improvement in LDL-cholesterol quality. This is not the first study to show that dietary changes can be superior to drugs – the DPP (Diabetes Prevention Programme) proved that lifestyle changes were superior to metformin in preventing the condition (DPP Research Group, 2002) – but Steven and Taylor emphasise the fact that VLCDs have more to them than brief weight loss.
The provisos are that this study is very small, and very brief, and the challenge following VLCDs is in the successful maintenance of weight loss long term, although there is a growing weight of evidence that suggests that durable success is possible. The underlying message is that, when that form to sign someone up for a commercial VLCD appears on your desk, sign it!
To view the summaries of each paper, please download the PDF of this article.
