Fruit In Schools started 10 years ago and provides 20 million servings of fresh fruit and vegetables to 480 low-decile primary and intermediate schools every day during the academic year.
The programme is funded by the Ministry of Health and managed by United Fresh NZ and the 5+ A Day Charitable Trust, which commissioned the research.
Forty-six per cent of principals saw fewer behaviour problems in the classroom, while 74 per cent said concentration in class had increased as a result of the programme.
Principals said the fruit provided "brain food" which helped kids concentrate and stay on task.
A further 66 per cent of principals reported an improvement in students' general health and 35 per cent said students had fewer sick days.
Bronwen Anderson, a 5+ A Day nutritionist, says: "By introducing fruit and vegetables to children we can encourage them to follow healthy, active lifestyles that will benefit them for the rest of their lives."
"It also provides learning opportunities such as how to cook and prepare food, recognising and naming different fruit and vegetables, and planting gardens."
Young people who don't embrace healthy habits can face negative long-term effects, Anderson says. "Poor diet in childhood is associated with obesity and increases the risk of a range of life-threatening illnesses in later life ...
"The great thing about the 5+ A Day Challenge is that it is achievable. For example, by simply swapping biscuits for an apple and a banana at morning tea, you are two steps closer to getting your 5+ A Day."
MAKE TIME
Cooking personality Annabelle White says kids appreciate personal touches from mum and dad - and this can make all the difference when they decide what to eat.
"The sandwich part of the deal is really important and quick to make," she says. "Work out what sandwiches work - crusts on, crusts off - or give wraps a go.
"Increasingly more dads are doing the lunchboxes, which is great. Kids love to say, 'Dad did this for me'."
And kids really like having little lunchbox compartments where little mandarins or apples can fit. "But you don't want anything that's too fabulous and draws too much attention because other kids will want it."
Holiday bake days can save time down the track, she says.
"I'm not saying every parent should do home baking but you could perhaps have a baking day in the holidays.
"There's lots of things that kids like such as muffins, biscuits and cookies that can be made healthy and put in the freezer.
"If you put it in a lunchbox in the morning it will act as a cooler and be defrosted by lunchtime."
EXPAND FOOD HORIZONS
Nutritionist Mikki Williden says parents should add variety to their kids' diets.
"Because they run around all day and have high energy requirements it's important to make sure they've got nutritious options at hand."
Avoiding pre-packaged foods is key, she says. "Often the challenge is getting your children to expand their options beyond the brightly coloured packets of potato chips all their friends are eating.
"Parents and caregivers are the main influencers of their diet, therefore what you do will impact on their likes and dislikes.
"Give them a choice out of the options you'd be happy for them to have, such as cheese slices, homemade muffins/loaves, fruit or salami sticks, so they have the final decision on what is going in their lunchboxes."
Be patient; adjusting to food changes can take time, she says.
"There is a natural food lag whereby children take a while to adjust to a particular food. Adults are the same; few people were born loving olives or goat's cheese.
"Research suggests that it takes around 10 different eating opportunities for a child to become familiar and then begin to enjoy a food."
That said, the advice from 5+ A Day is: "Don't force children to eat things - this will create negative associations and discourage them from trying again in the future."
INVOLVE YOUR KIDS
Ms Williden says parents should encourage kids to help with home baking.
"Yes, they are treats, but a much better option than store-bought ones. Many baked treats are still unnecessarily high in sugar so try reducing by one-third the amount of sugar that's in these foods and talk to your children about why it's good to do this."
White says parents should be involving their kids.
"Talk to your kids about how much sugar and fat are in food, or if you are baking, show them how much sugar's going in. Kids are open to learning those things. Emphasise how good fruit is and steer them towards healthy muesli bars, drinking water or possibly flavoured water or diluted juice.
"Packet crisps, fizzy drinks, and a lot of fruit juices which are very high in sugar and bad for their teeth, should be seen as treats."
The verdict? Ultimately, White says an "anything but the tuck shop" attitude is a good first step.
