Just one in ten women claimed they would struggle to cut down on sex, the Cancer Research UK study of more than 2,000 Britons showed.
The opposite was true of men. Women are also more confident of actually going through with their resolution, with 30 per cent claiming they could resist temptation.
But only 19 per cent of men believe they have the discipline to turn over a new leaf after the festive period.
Cancer Research UK carried out the research to coincide with a campaign urging people to abstain from drinking alcohol in January.
Robert West, professor of health psychology at the charity’s UK health behaviour research centre, said: ‘Some believe that willpower is like a muscle – it can get tired but it can also be strengthened with training.
‘The idea is that getting people to practice doing something that requires self-control builds a general ability to do this.’
Professor West added: ‘There are also studies showing that when people make their personal rules very clear with well-defined boundaries, they are more likely to stick to them.’