Men ditching unhealthy lifestyles may soon be able to live longer than women or have the same life expectancy as females for the first time since records began, a new study has revealed. By the time today's 12-year-old boys reach 30, they can expect to live to a month or so over 87 - matching the lifespan of the girls they are in school with today, the Daily Mail reported. Younger boys in England and Wales might even outlive their female classmates, an adviser to the Office for National Statistics has envisaged. Conventionally, males are the weaker sex in terms of life expectancy, with boys more likely than girls to perish in the womb and men dying earlier than women as adults. In Victorian times, the gap was comparatively narrow but a steady increase in male smokers meant it widened to six years by 1970 - the biggest gap since records began in 1841. Although the gap has since narrowed, other animal species exhibit a similar discrepancy, and it had been assumed that underlying genetic factors left men condemned to an earlier grave. But Professor Leslie Mayhew, a statistician at City University, London, thinks that the tide is turning. He insisted that the shift away from macho lifestyles towards the healthier approach more traditionally favoured by women was bringing with it the gift of longer life. Fewer men smoke, lung cancer rates have plummeted and heart attacks, while up to three times more common in men than in women, are much easier to treat than in the past. "There has been a huge decline in the numbers working in heavy industry; far fewer males smoke than before and there is much better treatment for heart disease, which tends to affect more males than females," Professor Mayhew said. The study differs from the official forecast. The professor, who describes the trend as 'well entrenched', has worked out that a boy born in 2000 will, from the age of 30, have the same life expectancy as a girl of the same age. But the Office for National Statistics has estimated that there will still be a gap of three and a half years. It asserted that several factors must be taken into account when making long-term projections and it is happy with its data. Professor Mayhew's calculations apply only from the age of 30 as baby boys are still expected to be more fragile than girls and young men have greater chances of dying in sporting and road accidents. He said that the ONS is too vigilant and men are catching up in other countries too. In Sweden, it will take only until 2024 for a 30-year-old man to have the same number of years ahead of him, on average, as a woman of the same age. British women's life expectancy is still increasing, but at a slower rate than men's. And higher rates of obesity in the female population could slow it further. Professor Mayhew's predictions are applicable only to England and Wales. Scotland, where life expectancy is usually lower, is excluded from the calculations. The study will be published by City University's Cass Business School.