Two children can eat the same box of sultanas and end up with very different risk to their teeth. One eats them in a few minutes after lunch. The other picks at them through the afternoon, a handful here and there. The second child's teeth spend hours under acid attack, while the first child's teeth have most of the afternoon to recover.
Both how much sugar a child eats and how often they have it affect decay. For children's snacks, the timing is often the easier thing for families to change, and it makes a real difference.
Each snack starts an acid attack
Bacteria in plaque feed on sugars and on cooked starches, which break down into sugars in the mouth. They release acid as they do it, and that acid draws minerals out of the enamel. Saliva gradually neutralises the acid and helps put minerals back, but this takes time, often half an hour to an hour.
When eating is spread out into regular meals and a couple of planned snacks, the teeth get long breaks to repair. Constant grazing or sipping means the repair never finishes, and the enamel slowly loses ground. Our article on how cavities form explains this cycle in more detail.
The total amount still matters too. The Australian Dietary Guidelines advise limiting foods and drinks with added sugars, and the World Health Organization recommends limiting free sugars, which include sugars added to food and drinks plus those in honey, syrups and fruit juice. Cutting the amount and cutting the number of sugar hits work together.
Good choices for the lunchbox
Foods that need chewing, contain little free sugar and do not cling to the teeth make good lunchbox snacks. Cheese is a standout. It contains calcium and phosphate, encourages saliva and can help raise the pH in the mouth after eating. Plain yoghurt and milk are good options for the same reasons, as long as they are unsweetened.
Crunchy vegetables such as carrot, cucumber, capsicum, snow peas and celery need plenty of chewing, which keeps saliva flowing. Whole fresh fruit is a healthy everyday food. Its sugars are packaged in fibre and water, and it is eaten fairly quickly, so it is a very different proposition from fruit juice or dried fruit.
Boiled eggs, wholegrain crackers with cheese, hummus with vegetable sticks and leftover pasta or meat are other savoury choices that keep children full without much sugar.
After school, when grazing creeps in
The after-school stretch is when many children snack non-stop until dinner. A set afternoon tea, eaten at the table and then cleared away, can make a big difference. If your child is hungry again before dinner, offer something savoury and water rather than a second sweet snack.
Plain popcorn and nuts are low in sugar, but whole nuts and popcorn are choking hazards for children under five. Use nut spreads or ground nuts for younger children, and keep popcorn for school-age children who can chew it safely.
The snacks that do the most damage
The foods hardest on children's teeth combine sugar with a slow eating time or a habit of grazing. Dried fruit, fruit straps, muesli bars and chewy lollies are high in sugar and easy to pick at. How sticky a food feels is a poor guide to how long it stays on the teeth, though: a study in the Journal of Dental Research (Kashket and colleagues, 1991) found biscuits, crackers and chips were retained longer than caramels or raisins. Hard lollies and lollipops are sucked slowly, so the sugar sits in the mouth for a long time. Sour lollies add acid on top of the sugar.
Starchy savoury snacks like chips, pretzels and many crackers are not sweet, but they turn soft and pasty and pack into the teeth. They are fine as part of a meal, less so as an all-afternoon nibble.
Drinks deserve a special mention. Fruit juice, cordial, flavoured milk, sports drinks and soft drinks deliver sugar in a form that reaches every surface, and they are easy to sip for long periods. Water, ideally fluoridated tap water, is the best drink between meals. For babies and toddlers, our article on baby bottle tooth decay explains why bottles of milk or juice at bedtime are a particular risk.
Treats without the guilt
No food has to be banned. Birthday cake, a few lollies at a party or a chocolate after dinner are part of childhood. The practical rule is to have sweet foods as part of a meal, or straight after one, and then finish with a drink of water. Saliva flow is higher at mealtimes, and the teeth face one acid attack instead of several.
Sugar-free lollies and drinks lower the sugar load, but many are acidic and can still soften enamel, and they keep the grazing habit going. They are a reasonable occasional swap rather than an everyday snack.
Brushing and other protection
Good food habits work best alongside brushing twice a day with the right amount of fluoride toothpaste for your child's age, which our guide to children's fluoride toothpaste sets out. Fissure sealants on the deep grooves of back teeth can give extra protection for children at higher risk, as described in our article on dental sealants.
What parents ask about snacks
Is fruit bad for my child's teeth?
Whole fresh fruit is not a concern at normal amounts and is an important part of a healthy diet. Dried fruit, fruit straps and juice are the forms to limit.
Should my child brush after every snack?
That is not necessary. Twice a day with fluoride toothpaste is the goal. A drink of water after a snack helps clear food. After something acidic, such as fruit juice, waiting a while before brushing is gentler on the enamel.
How many snacks a day is reasonable?
Most young children do well with three meals and two or three planned snacks. The point is to have clear gaps between eating times, rather than to hit a particular number.
Diet advice at a family check-up
Our dentists and oral health therapists can look at your child's teeth for early signs of decay and talk through what your child eats and drinks in a practical way. You can read about our family dental care or check what is available for new patients on the current deals page before booking in Melrose Park.
