Many parents think they’ve packed their child a healthy lunch to get them through the school day, but a lot of convenient choices are high in sugar – and it all adds up.

For example, a lunch that includes a box of sultanas, a flavoured yogurt and a fruit juice is delivering more than double the recommended daily amount of sugar.

The World Health Organization recommends we eat no more than 25 grams (about six teaspoons) of free sugars a day for optimum health. Free sugars are those added to food and drinks or that occur naturally in honey, syrups and fruit juices.

There are more than six teaspoons of sugar in a single serve of some products such as apricot bars, cakes and sports drinks, and some products marketed as being healthy – such as muesli bars and on-the-go breakfast products – are surprisingly high in sugar.

Consuming too much sugar is an indicator of poor dietary patterns and excessive energy intake. This is a risk factor for excess weight gain and nutrition-related conditions, such as dental caries and Type 2 diabetes. In 2016, 22 per cent of children in NSW aged 5 to 16 years were above a healthy weight.

Limiting children’s sugar intake is vital to the prevention of tooth decay, as bacteria in the mouth break down sugars found in food and drinks to create acids which then erode the tooth enamel, leading to decay. Almost 37 per cent of NSW children aged 5 to 10 had decay in their baby teeth, while one-fifth of children aged 6 to 14 had decay in their permanent teeth, according to the National Child Oral Health Study 2012-14.

ADA NSW’s Dr Sarah Raphael, a specialist paediatric dentist, says it’s not just the sugar content of foods that parents need to be aware of, but how sticky foods are and how long sugary foods stay in the mouth.

“Snacks that get stuck in the grooves of the teeth for long periods and sugary drinks that are continually sipped both put teeth at high risk of decay,” she says.

“Foods that are chewed and swallowed quickly tend to be less harmful for teeth. Even better are those foods that help to clean the mouth, such as vegetables and hard cheese.”

Dr Raphael says it’s important to limit the amount of time children spend snacking or drinking anything other than water so that saliva, the mouth’s natural cleaner, has the chance to wash away food particles and provide minerals to keep teeth tough.

“Drinking tap water is also important because it washes sugars and acids away and often contains fluoride for extra protection against decay,” she says.

Lindy Sank, Accredited Practising Dietitian at the Sydney Dental Hospital, says there has been a massive increase in mini snack packs being promoted as ideal for lunch boxes.

“The result is a lot of confusion for parents trying to make good choices and children often receiving many more items than is recommended for health,” she says.

Parents sometimes pack three or four processed or packaged food items a day in their child’s lunch box.

“Ideally processed snack products should be limited to one item and ideally a low-sugar choice, such as popcorn, rice crackers, cheese and wholegrain crackers.”

Ms Sank says parents are often misled by health messages on food packaging, with many packages highlighting the healthier components of the product. She says descriptions like “natural”, “fat free”, “no added sugars” and “no artificial colours or flavours” distract from other aspects of the product, such as having high free sugar and energy content, limited nutrients or being processed.

Professor Clare Collins, Professor of Nutrition and Dietetics at the University of Newcastle, reminds parents to think about the healthy foods that can be added to lunch boxes quickly, and says most supermarkets now sell kid-size fruit for lunch boxes.

“The most recent National Nutrition Survey results found that children do not meet the recommended daily serving for the core healthy foods including vegetables, dairy products, wholegrains, lean sources of protein and fruit,” she says.

“Swapping highly-processed snack and packaged foods for more of the basics is the best way to give children the energy and nutrients their bodies and brains need to perform well at school. Easy items to drop in a snaplock bag in the lunch box include cherry tomatoes, snack cucumbers, baby carrots and a handful of salad leaves. Mini cans of baked beans, canned salmon and tuna are great too.”

Professor Collins suggests freezing small milk poppers or a water bottle to keep the lunch cool.  “Get ahead on the weekend by making and freezing sandwiches to grab during the week,” she says.

Visit www.healthykids.nsw.gov.au or www.healthylunchbox.com.au for more tips.