Is there a place for low-energy formula diets in weight management?

Adrian Brown is a Specialist Weight Management Dietitian, Imperial College London; Gary Frost is Professor of Nutrition and Dietetics, Imperial College London; Shahrad Taheri is Visiting Professor of Medicine, Imperial College London and Weill Cornell Medical College in New York, NY, USA, and Doha, Qatar. While reduction in energy intake is key to weight loss, it is challenging in practice to achieve a sufficient calorie deficit to achieve clinically significant weight loss. With indicators that a greater weight loss within the first year is a good predictor of long-term weight loss maintenance, the use of dietary methods to give a substantial early energy deficit could be beneficial. Low-energy (800–1200 kcal/day) formula diets (LEDs) and very-low-energy (<800 kcal/day) formula diets (VLEDs) have recently gained popularity in clinical practice as a tool to enable patients to achieve this substantial calorie deficit and, therefore, lose a significant amount of weight, with consequent improvements in obesity-related comorbidities. This review examines the current evidence for the use of LEDs and VLEDs for weight loss and improvements in obesity-related comorbidities, while helping to inform clinicians on their potential use in clinical practice.