A world-first study may have found the answer to a long life.

Almost 1000 people over the age of 80 in the Bay of Plenty have been examined to see how they have achieved longevity.

Eating well, keeping active and staying social were common themes amongst those surveyed.

The study's co-lead, Auckland University researcher, Ngaire Kerse, told Mike Hosking the participants are part of a generation before takeaways.

She says nutritional patterns and physical activity are key to a long life.