Weight losses with low-energy formula diets in obese patients with and without type 2 diabetes: systematic review and meta-analysis


Ws Leslie et al. UK


International Journal of Obesity (2016), 1-6


The purpose was to conduct a systematic review of published data, in order to compare weight loss following a very low-calorie diet, VLCD (< 800 kcal per day) or low-calorie diet, LCD (> 800 kcal per day) in patients with and without type II diabetes.

Patient Group:

Adults aged 43-55 years suffering from obesity (>30 kg/m2) with or without diabetes.


The selection of studies was done through a systematic electronic search in Medline, Embase and CINAHL with studies conducted between 1946 and 2015. The studies selected were non-randomised or randomised controlled studies focusing on weight control. The quality and any sources of bias were assessed by two independent reviewers.


The systematic search identified 151 potential studies, in which 17 studies were selected in their full-text form for further examination. Of these studies, 5 studies met the criteria for inclusion. Studies show results from USA, Australia, the UK and Sweden from different environments such as inpatient care, primary care, an endocrinology clinic, an obesity clinic and from a surgical unit.

The weight of the patients upon beginning treatment varied between 99-126 kg (BMI: 30-42.6 kg/m2). The total weight loss varied between 8.9 and 15 kg among patients with diabetes, and 7.9 and 21 kg among patients without diabetes. The treatment varied between 4 and 52 weeks.

Transient side effects such as constipation, dizziness, hypotension, dry skin and bad breath were confirmed in two studies. More serious side effects were reported in one study and included hypoglycaemia and myocardial infarction.


The total weight loss varied between studies and was dependent on a number of factors, such as how long the diet continued, age, sex and health. The results showed no difference in weight loss between persons with or without diabetes, which was also reported in previous studies. Neither was there any difference in weight loss between the various diet groups, and similar results have also been shown in other studies.

The weight loss was a constant 1.2 to 3.2 kg per week in several studies, but not in all of them. This can be explained inter alia by differences in the length of treatment, where one study continued for 52 weeks, and where all meals were replaced for different periods of time.

A strict regimen with meal replacements has also proved to be a safe therapy method with few side effects. The side effects reported in these studies have not been directly related to diet.

New methods for weight control are needed for persons with type II diabetes, and a strict regimen with meal replacements can be an alternative during the weight-loss phase.


Weight loss with VLCD and LCD are very similar in terms of results; furthermore, there is no difference between patients with and without diabetes. These diets should be able to contribute to new weight loss goals of 15 to 20% for persons with serious and medically complicated obesity.