The president of the British Medical Association has voiced doubts over the government’s “nudge” approach to public health.

Speaking at a lecture for the family support organisation Home Start, Sir Michael Marmot said: “If you are someone of low income and you can’t get access to healthy food it’s going to be hard to nudge, push or expect those people to eat healthily.”

He added: “I’m open to the evidence, but I don’t find the evidence very persuasive.”

Cabinet Office minister Francis Maude responded, saying: “Is it [nudge] the answer to everything? Probably not, but certainly it is well worthwhile seeing if we can do something that is pretty cheap.”

The government’s behavioural insight team, an arm of the Cabinet Office, is devising ways of using nudge theory to encourage healthy behaviour by incentives. This month it launched a pilot scheme for smoking cessation contracts and rewards for quitting.

Professor Marmot’s Fair Society, Healthy Lives review, published last year, set out evidence that social inequality leads to health inequalities.

He welcomed December’s public health white paper, saying it had “exceeded” his expectations by explicitly responding to his recommendations and having the social determinants of health “at the centre”.