Grants given to families should be made to men, not women, because they make better decisions on how to spend the money, a visiting philanthropist says.

Henry LaKelly Hunt, the son of an American oil tycoon, is the co-founder of Men Moving Millions, an organisation set up to encourage wealthy men to donate money to men in need.

Hunt, who was in New Zealand last week, believes men look to fix the whole problem, while women tend to reinvest in other women.

"I just know that men's hearts are all about a healthy community for their children to be held by. They want the whole community to be healthy," he said.

"There is some research out that money in a woman's hands goes to what interests the woman. But when it gets into a man's hands, if he gets educated, he wants his family to get educated and the whole community to get educated. Once men get access to resources, they want to spread them through the community."

"Men and boys have the solutions to so many of community problems, but only recently have men and women begun writing cheques to men and boys."

His mantra is: If you want to invest wisely, invest in a man. He says that is the secret to turning around struggling communities.

"Around the world, less than 10% of foundation grants go to men and boys, but they have requirements that shouldn't be overlooked."

Hunt says his point of view is starting to be backed by the United Nations and the World Bank, which last year documented the way men had transformed urban slums in Vietnam by borrowing to invest in toilets and water.

"The UN has started to emphasise if you want to help the world, stabilise the men in communities. If the men become stabilised, then they help their families, and the whole community gets stabilised.

"If you want to move into the poorest parts of the world and help financially, put money in the hands of a man, because that is the smartest investment you can make."

Once a man was helped financially, they often passed it on. "It's just their nature to make sure the giving keeps going."