Parental pressure is stopping early childhood centres from providing cake at children's birthdays, teachers say.
A recent Auckland University study of early childhood menus found about half regularly included unhealthy or occasional food such as cake and other treats.
But many centres told RNZ they no longer served cake regularly, and it was seldom served even at children's birthdays because parents preferred healthier options.
At Adelaide Early Childhood Centre in Wellington, team leader Karen O'Leary said there was usually no birthday cake because parents were worried that cake was being served too often.
"We shifted the policy to be that only at the fifth birthday, or at a leaving party, cake would be fine and you could bring whatever you liked for those parties.
"At other times you would just bring things like plain popcorn, fruit kebabs, that kind of thing."
Ms O'Leary said for her own birthday the centre served a special treat called 'sausage cake'.
"It's a really delicious cake. It's basically made up of sausage meat which is very good for you and it comes with a delicious tomato sauce icing."
She said some of the children liked sausage cake.
"It's like other cakes. They generally just eat the icing and throw the rest away."
Sausage cake was not on the menu at Little Wonders' Wellington centre but the chef Kim Cunnington said it did serve its own special type of cake.
"It's packed with sunflower seeds and pumpkin seeds," she said.
"Not all cake needs to be packed with icing and sugars."
The head teacher at the centre, Sarah Jimmieson, said early childhood services could end up serving cakes very regularly due to birthdays and other special events.
She said one advantage of serving less treat food was that it put the emphasis of birthdays back on the child.
"We make it more of a focus around the individual child and how that's a special day for them and we're celebrating them rather than having a focus around food."
At Hill Street Early Childhood Centre in Wellington parents often brought fruit instead of a cake when their child had a birthday.
But the head teacher Claire Jongepier said cake and other treats were okay sometimes because children needed to learn to make their own decisions about food.
"We don't eliminate every single unhealthy food because we want children to know that's a treat," she said.