Such sponsorship promoted consumption of junk food and undermined recommendations promoting healthy eating, Professor Signal said.
Rugby had the most unhealthy sponsorship by far, although the sport also had a healthy sponsorship from Weetbix which was positive, the researchers said.
Sponsors were classified as healthy or unhealthy using the New Zealand Food and Beverage Classification System nutrient criteria for energy, fat, sodium and fibre levels.
According to the university's Dr Moira Smith, whose PhD explores the perceptions of children and parents about food in sport, while many parents believed children's sport would not be sustainable without food and drink sponsorship, food and drink sponsors likely contributed only small amounts of funding to children's sport.
"Often benefits are in kind, such as player of the day vouchers which promote unhealthy food to children. There is a funding fallacy about junk food and sport in New Zealand," Dr Smith said.
Junk food also dominated sport in Australia, according to visiting nutritionist Dr Bridget Kelly.
Dr Kelly is a keynote speaker at workshops on Food in Sport being held in Wellington and Auckland today and tomorrow with sports administrators, coaches, caterers, teachers and others interested in food in sport.
The research is funded by the Health Research Council.