"Ladette" lifestyles among young women are partly to blame for narrowing the life expectancy gap between the sexes, say experts.
Latest figures from Statistics New Zealand show the fairer sex are living 82 years on average, four years longer than men.
But the gap has closed considerably since the mid-1980s when lifespans lasted 77 years for women, and just 71 for men.
Smoking, binge-drinking and fast food diets are all factors, as women increasingly emulate men's unhealthy habits, say experts.
The stress of working long hours is also affecting female life expectancy.
Nutritionist Nikki Hart said more women were "drinking like the boys", and increased alcohol intake was linked to breast cancer. "It's become more acceptable to drink. It doesn't surprise me that with our habits we are losing the advantage over men."
Waikato University director of population studies Professor Natalie Jackson said the increase in smoking-related deaths was partly due to cigarette advertising campaigns from the 1940s and 50s.
"We're seeing that translate into cancers now."
Jackson said the next issue to impact on lifespan was obesity levels, which have risen significantly among children in the last decade. She said the next generation of elderly people is predicted to be less healthy than the current one.
As well as drink and diet, Auckland University demographer Dr Ward Friesen said work was a factor in changing life expectancies, with more women working - and enduring employment-related stress.
Auckland office worker Shannon Goldstone, 24, doesn't smoke and eats well, but has noticed different behaviour in women her age.
"I know a lot of my friends drink and smoke a lot more."
She said lifestyles had changed greatly in the past few decades, adding she was 15 when her mother decided to start work.
But she was comforted by the thought of men living longer.
"I don't like the idea of being left alone for 20 years," she said.
Aucklander Kayla Hamilton, 24, said women led a far different life to that of previous generations.
"My mum and my grandma wouldn't be buying takeaways in the weekend," she said.
Her friend, Nikki Tunbridge, 26, agreed the older generation of women in her family lived differently.
When her mother was 26 she was a stay-at-home mum and her grandmother hadn't worked.
In 1900, New Zealand became the first country where people reached a life expectancy of 60 years, whereas now we rank 13th in the world.