HCR Update from Mark Sanna: As part of The Lancet's ongoing series on obesity, the authors used a simulation model to project the probable health and economic consequences in the next two decades from a continued rise in obesity in ageing populations. They project millions more cases of diabetes, heart disease, stroke, cancer and conclude: "The combined medical costs associated with treatment of these preventable diseases are estimated to increase by $48—66 billion/year in the USA.