Outcomes and predictors for weight loss using a commercial Low Energy Diet in overweight adults at increased risk of diabetes in PREVIEW trial

Abstract

Recent epidemic in obesity and Type 2 Diabetes Mellitus (T2DM) has raised extensive interest in weight loss and T2DM prevention strategy. Obesity is believed to play a crucial role in development of number of complications, including metabolic syndrome which can lead to T2DM. This in turn is closely related to medical complications, such as cardiovascular disease and hypertension. Countless weight loss strategies were developed for obese individuals, in an attempt to minimise these obesity related complications. Low Energy Diet (LED), is one of the most effective weight loss method available, which provides ~4MJ of energy for the consumer, along with protein with low fat and minimal carbohydrate as well as all the essential micronutrients to induce physiological ketosis for effective lipid removal from the body. The PREVIEW trial is a 3 year randomised controlled trial that utilises LED for initial aggressive weight loss followed by 3 year weight maintenance phase, to find out the most effective lifestyle pattern for prevention of weight regain and T2DM. The aim of this project was to find out the effects of LED on weight loss along with other physiological characteristics, such as fasting plasma glucose (FPG), waist circumference and lipid profiles, which are all independent risk factors for metabolic syndrome and thus T2DM development. Another aim was to find out the predictors of weight loss, in that how does the gender, age, FPG, plasma lipid profiles, waist circumference and ethnicity correlate with weight loss and why such outcome was evident. After 8 weeks LED programme, clear weight loss pattern was visible among all 65 participants who have achieved 8 % or more initial weight loss. Detectable reduction in FPG, waist circumference, fasting lipid profiles were seen among these individuals, however when correlations were made, variable patterns were evident indicating that different weight loss predictors have varying strength on its influence on weight loss. Mean (SEM) absolute and percentage weight loss in 65 participants were 11.6 (0.49) kg and 10.8 (0.26) % respectively. In this study, clear beneficial outcome was visible in participants who have completed 8 weeks LED programme, across many physiological aspects such as weight loss, FPG, lipid profiles and waist circumference lowering the severity of metabolic syndrome in many individuals. Variable weight loss predictors had different influence on actual weight loss. Other previous studies have focused on predictors of weight loss, which some of the outcomes did not match the outcome of this study indicating further research is required for valid relationship between predictors and weight loss. Overall, this study has proven that LED for 8 weeks along with medical supervision was able to induce short term aggressive weight loss and thus reducing T2DM risk, however future studies will be required to address further questions in this field.