Coffins as big as bookshelves are needed in the wake of New Zealand's obesity crisis.

Latest Ministry of Health data shows that 70 per cent of people in the Bay of Plenty are overweight or obese.

Director of Rotorua's Osborne's Funeral Directors Sam Osborne says coffin sizes have changed over the last eight years to accommodate larger bodies.

He says options include a standard, second and third oversized coffin.

Osborne says the work of embalming is becoming a two-person job despite having better lifting devices.

He says extra handles are also being added so that more people can help carry them.

In some cases, a long bar on each side is used to allow up to six people on each side.