Energy restriction and energy balance remain the key elements in achieving weight loss. This chapter discusses the use of meal replacements for weight management in obese adults. It explores the use of group‐based interventions across a range of obesity treatments and examines evidence for the effectiveness of group‐based approaches for obesity management in adults. The combination of regular physical activity, cognitive‐behavioural modification of lifestyle and effective anti‐obesity drugs is more likely to achieve weight loss maintenance. The chapter explains the indications, benefits and risks of weight loss surgery; types of procedures available and their controversies; future developments in bariatric surgery; and translational work in the field. It considers and evaluates the most common psychological interventions currently employed in the treatment of obesity. Health costs of obesity and the longer‐term impact and cost‐effectiveness of weight management interventions are required to guide future spending on this disease.