The obesity epidemic has the ability to undo the work of statins and smoking cessation on the prevalence of cardiovascular disease. It is well accepted that obesity is associated with an increased risk of cardiovascular disease and as such weight loss is often suggested to prevent cardiovascular events. Is this increased cardiovascular risk simply related to increased prevalence of adverse cardiovascular risk factors, such as hyperlipidaemia and hypertension, or are there adipose tissue specific factors that add to this effect? There is also conflicting evidence that once coronary heart disease is established, obesity appears to be protective. Achieving meaningful weight loss in individuals is difficult with only a fraction of patients even losing 5kg, which has led to difficulties in evaluating the effects of weight loss on cardiovascular events. This presentation will discuss the relationship between obesity and cardiovascular disease and the obesity paradox in established cardiovascular disease. The effects of weight loss on cardiovascular risk factors, surrogate markers and cardiovascular events will be presented, highlighting the gaps in the current understanding of this important area.