There are calls for the Government to invest in dietitians, in a move that could potentially save billions of dollars.

A report from Dietitians New Zealand shows 24 per cent of general practice visits could be helped by a dietitian.

General Practice NZ chair Dr. Jeff Lowe told Mike Hosking most GPs work in limited timeframes, and adding a dietitian to the team would make a huge difference.

"Now if I want a dietitian that's publicly funded, I have to refer to the hospital and the hospital is swamped with patients that need to see them. So they're a scarce resource."

Lowe says it creates a discouraging situation to be referred to in the first place.