A team of health researchers is calling on the Government to keep junk food away from children's sports fields.
Associate Professor Louise Signal, of Otago University, is leading research into the promotion of sugary drinks, lollies, chips and burgers in a children's sports environment described as "awash with junk food".
Eleven per cent of New Zealand children aged between 5 and 11 are considered obese, up from 8 per cent in 2006/7, and at least 20 per cent are overweight.
The Health Research Council-funded research project, a collaboration between Otago University and Victoria University, has found much work is needed to make children's sport healthier.
The researchers called for healthy food policies, support for coaches and managers, and restrictions on marketing junk food to children.
Dr Signal said the wide availability and promotion of junk food in sport undermined the sector's efforts to promote healthy eating to players.
"There is still room for treats in our lives, but given the alarmingly high rates of overweight and [obese] ... children, the saturation of junk food in sport needs to be examined."
But Food and Grocery Council chief executive Katherine Rich said any claim that children's sport was saturated with junk food was "highly exaggerated".
"I'm surprised at that kind of emotive language being used in academic research, because it's very hard to reconcile those comments with experience as a parent spending a lot of time on the sideline."