As things stand, one third of children are overweight or obese by the time they leave primary school, and two thirds of adults weigh too much. Significiantly, those most prone to obesity, who are mainly in less well-off and poorly educated households, are least likely to take any notice of nutritional advice and most likely to be susceptible to price disincentives. But these are also the households for whom any rise in the price of food is especially regressive.