Abstract

In the UK, over 50% of adults are overweight (body mass index [BMI] of 25–29.9kg/m²) or obese (BMI 30kg/m² or more); it is thought that over half of the UK population could be obese by 2050 because of the increasing availability of calorie-dense food and sedentary lifestyles.1–3 Interventions to achieve weight loss include diets, increased physical activity, behavioural modification strategies, drugs (e.g. orlistat) and bariatric surgery.4 Dietary interventions include low-calorie diets (LCDs; 1,000–1,200kcal/day for women and 1,200–1,600kcal/day for men), very low calorie diets (VLCDs; including Very Low Energy Diets [VLED]; below 800kcal/day) and Low Energy Liquid formula diets (LELD; above 800kcal/day).4,5 However, drop-out rates from such interventions are often high. Here we consider the safety and effectiveness of VLCDs and practical issues about their use.