Packing a healthy lunch box for your kids can be more confusing than algebra or folding a fitted sheet. But it's important — children consume about one third of their food at school. Lunch boxes needn't be complicated. Just follow a few dietary principles.

1. Start with grains

Whole grains and cereals are an excellent source of carbohydrates, which fuel your child's body and brain. They're also a source of fibre, which is linked to a lower risk of obesity, type 2 diabetes, heart disease and bowel cancer.

Kids aged up to 8 years need 4 serves of wholegrain cereals per day; from 9 to 11 years, they need 5 serves. Providing all kids get up to 3 serves of wholegrain cereals across breakfast and dinner, 2 serves in their lunch box should be enough. Each item represents one serve:

• one slice wholegrain or wholemeal bread
• ½ medium wholegrain bread roll or flatbread
• ½ cup cooked brown rice, pasta or quinoa

2. Add lean protein

Lean meat, fish, chicken, eggs and plant-based protein such as beans, tofu and nuts give your child the iron, zinc, vitamin B12, essential fatty acids and protein needed for growth and brain and muscle development.

Kids aged up to 8 years need 1½ serves of protein daily; from about 9 years old they need 2½ serves per day. Nuts may be banned at your child's school, so try incorporating some of these nut-free protein sources into your child's lunch box. Each item represents one serve:

• one small tuna can
• 2 hard-boiled eggs
• 80g cooked chicken or turkey
• one cup cooked or canned chick peas

3. Throw in some veggies

Because vegetables provide energy, vitamins, minerals, antioxidants, fibre and water, veggies help to protect your child from diseases. With the exception of avocados, veggies are usually low in fat. Avocados are full of 'healthy' monounsaturated fats though, so they’re still good for your kids to eat.

School kids aged 4 to 8 need 4½ serves of vegetables daily, which increases to 5 serves from age 9. Add some of these veggies to your child's lunch box. Each item represents one serve:

• one medium tomato
• ½ cup sweet corn
• one cup raw vegetable sticks, for example, carrot, snow peas, capsicum
• one cup green leafy vegetables

4. Pop in some fruit

Make that whole fruit. Most Australians only consume about half the recommended serve of fruit, and many people drink too much fruit juice. Fruit juices are high in energy (kilojoules), low in fibre and can damage teeth. Encourage your child to drink water.

Pieces of whole fruit, however, are chock-full of vitamins, minerals, fibre and disease-fighting compounds called phytochemicals.

School kids aged 4 to 8 should have 1½ serves of whole fruit daily; children aged 9 and over can have 2½ serves. Including 1 or 2 of these should add some healthy sweetness to your child's lunch. Each item represents one serve:

• one medium apple, banana, orange or pear
• 2 small apricots, kiwi fruits or plums
• one cup diced or canned fruit (with no added sugar)

5. Don't forget the dairy

Most children should have calcium-rich dairy — for example, milk, cheese, yoghurt — every day to ensure they build strong bones and teeth. Milk also provides protein and vitamins such as vitamin B12. It's recommended that kids aged 2 and over consume mostly reduced-fat dairy.

If your child can't digest dairy, they can also get calcium from other sources, such as almonds, firm tofu, sardines, pink salmon and soy milk fortified with calcium. Some nut and oat milks have added calcium, but they lack vitamin B12 and sufficient protein, so always check with your GP or dietitian before using them.

Boys aged 4–8 should have 2 serves of dairy or dairy alternatives per day; for boys aged 9–11, it's 2½.

Girls aged 4–8 should have 1½ serves of dairy or dairy alternatives per day; for girls aged 9–11, it's 3.

Combine any of these options to get your child's daily dose of calcium. Each item represents one serve:

• one cup low-fat milk
• 2 slices or 4 cubes of hard, reduced-fat cheese
• 200g yoghurt
• 120g ricotta
• 100g firm tofu

Sample lunch box plan

Assuming you have a 6-year-old child, this sample lunch box should fulfil all their nutritional needs for the school day. It should ensure they don't still feel hungry, and allow them to concentrate, learn and play like a boss. For older children, increase the servings accordingly.

Morning tea

• one cup veggie sticks (carrot, snow peas, capsicum) and one small plum

Recess

• one banana and 4 cubes of hard, reduced-fat cheese

Lunch

• wholegrain sandwich (2 slices) with tuna, egg, tomato and salad leaves, and one small tub of yoghurt

For more information

• Learn about healthy eating for kids on the Pregnancy, Birth and Baby website.
• Discover more about your child's health.
• Seek more advice on your child's nutritional needs at Nutrition Australia.
• To locate a qualified dietitian, visit the Dietitians Association of Australia.

This post was originally published on 8 February 2019 and has been updated to include the most recent details on this topic.