School lunches can be a mixed bag - but a fresh bid to regulate them could change that.

Health researches are joining the call for a national health food policy to be adopted by our schools.

It would include similar menus as those seen in our hospitals - heavy on fruit and vegetables and low in sugar and fatty foods.

Auckland University Nutrition researcher Cliona Ni Mhurchu told Tim Dower poor food choices are the number one case of bad health.

"In New Zealand most kids bring their lunches to school but about 90 percent of schools in New Zealand actually do provide some form of food, so what we are really calling for is standards around the kinds of foods that are available in schools.

LISTEN ABOVE AS CLIONA NI MHURCHU SPEAKS WITH TIM DOWER