The Government wants every obese preschooler referred to a GP before they start school.
Its new Raising Healthy Kids programme starts on Friday, and is aimed at combating high levels of childhood obesity.
"Obesity is a serious issue threatening the health of young New Zealanders," says Health Minister Jonathan Coleman.
"In 2014/15, 11 percent of all children aged two to 14 years were obese. The figures for Maori and Pacific children are 15 percent and 30 percent respectively."
At the programme's announcement at Birkenhead Plunket on Auckland's North Shore, Prime Minister John Key explained the need for intervention.
"We are obviously very concerned about making sure that youngsters get the best start in life and are in the best physical conditions," he says.
"Obesity is an issue that we face in society, and one of the things we want to do is make sure we have those tests."
The target is to have 95 percent of four-year-olds who are identified as obese during their routine B4 School Check, offered a referral to a GP.
Mr Key says obesity is "a family and cultural issue," and it is important to identify it and intervene early.
Dr Coleman says more than 1400 children have been referred to a GP for support with healthy eating and activity in the last year, and he expects this to increase to 4000 a year from December 2017.