No matter how healthy they claim to be, packaged foods should be avoided in the lunchbox, say nutrition experts.
The Bay of Plenty Times Weekend set out to find out what the perfect school lunchbox should contain.
The resounding answers were a bread meal, a piece of fruit and some sort of protein.
Things to avoid were packaged foods such as potato chips and fruit strings.
Tauranga registered dietitian Fiona Boyle, of Food Solutions, said like other meals, balance was the important thing in a lunchbox.
"You want something carbohydrate-based, whether bread, wraps or good healthy crackers. Pasta or rice salad is another good option. You also want some protein - meat, fish, chicken, cheese or yoghurt, and some sort of vegetables in there as well, whether in a salad sandwich, or at least having fruit."
Ms Boyle said parents could be tempted to load their trolleys with lots of packaged food, such as muesli bars or potato chips, but these should not be eaten daily. She said parents were often buying their children fruit strings or pulped fruit snacks but real fruit was far more preferable.
Drinking lots of water at school was also important, Ms Boyle said.
Toi Te Ora - Public Health Service health-improvement adviser Tiana Hackett said children consumed about one-third of their daily energy intake during school so it was important lunchbox choices reflected this.
Mrs Hackett said fruit and vegetables were a quick and easy option to meet energy requirements. To keep costs down for parents, buying seasonal fruits was the best option, Mrs Hackett said.
"Minimising or even removing packaged items such as lollies, chips, biscuits and other high-sugar and saturated-fat options is a bonus and many schools around the Bay of Plenty are working toward ensuring this message is communicated home to parents."
Mrs Hackett said water was essential for healthy brain development and improved cognitive abilities in children and teenagers.
NZ Nutrition Foundation dietician Sarah Hanrahan said it was important to pack food the child liked, so it would get eaten.
Ms Hanrahan said parents should not worry about monotonous meals if their children were eating them.
"You need something bready and easily transportable, like wraps or a sandwich, something fruit or vegetable, and a small treat like a biscuit or a little muffin.
"Things that will sustain the kids, like nuts, are good if they are allowed them at school."
Ms Hanrahan also suggested choosing healthier options where possible, such as wholegrain bread, leaving the skin on apples, and a piece of fruit rather than juice.
She said using a lunchbox separated into portions was useful as it helped keep portion sizes sensible.