It has been a frustrating week for well-intentioned and interventionist political leaders. Michael Bloomberg and David Cameron have been roundly defeated in their efforts to prod citizens into health.

Both the mayor of New York, who wants to limit the size of sugary drink cups in restaurants and cinemas, and the UK prime minister, who sought a minimum unit price for alcohol, lost the argument. They were portrayed as social nannies pushing policies that discriminated against the poor and minorities, who deserve some pleasures.

They were still right. Societies should try to limit alcoholism and obesity, as they have cracked down on tobacco use. Freedom matters and the ideal policy is both effective and unobtrusive, but they both managed to tread the line between illiberalism and irresponsibility. As with tobacco proscriptions, they will probably be accepted in the end.