Dietary Tips to Help Prevent Cavities in Teens

Tokyo International Dental Clinic Roppongi near Azabu-juban advice the dietary habit for young adolescents

Dietary Advice

Ages 10 to 14 are an important time, as most permanent teeth come in during these years. Teens also have more opportunities to choose their own food and drinks, which can mean eating or drinking sugary things more often. That makes it important to take care of their teeth.

Global studies suggest that about half of children and teenagers have experienced tooth decay in their permanent teeth. High sugar intake from drinks such as juice and foods such as sweets is also a concern among teens.

A study published in 2026 pointed out that some dietary advice about protecting teeth can be vague or difficult to understand. Here are the study’s main points in simple terms.

1. “How much sugar is too much?” can be unclear

There is plenty of advice about daily sugar limits, but the recommended amounts can vary considerably depending on the source. Some recommendations range from the equivalent of 6 teaspoons to more than 18 teaspoons a day.

The World Health Organization (WHO) recommends that “free sugars”—a type of sugar—make up less than 10% of a person’s daily energy intake. Ideally, they should make up less than 5%.

Free sugars include sugar added to drinks and processed foods, as well as sugars found in drinks such as fruit juice.

Advice such as “cut back on sweets” or “eat less sugar” can be hard to follow if you don’t know what amount is appropriate. Check food labels to see how much sugar a product contains and how much you are eating.

2. Don’t overdo it with 100% fruit juice

Having a sugary drink with a meal rather than between meals may reduce how often your teeth are exposed to sugar. However, drinking juice with every meal can still add up to a high total sugar intake over the day.

Even 100% fruit juice contains sugar. For example, a glass (about 236 mL) may contain around 20–25 grams of sugar. Drinking that much with every meal can add up quickly.

It’s important to think not only about when you drink juice, but also how much you drink. UK guidelines recommend limiting 100% fruit juice to 150 mL a day.

3. Sugar can be found in foods that don’t taste sweet

Labels such as “low sugar” or “less sweet” may have different meanings in different countries and regions. So, a label alone may not tell you whether a product is low in sugar.

Sugar is also sometimes added to foods that don’t taste very sweet—not just sweets and drinks. Examples include:

Ketchup, pasta sauce, and salad dressing
Canned soup
Bread and sushi rice
Ham and sausages
Flavored yogurt and cereal bars
Dried fruit

When choosing processed foods, check the nutrition facts and ingredients list—not just the front of the package.

4. Diet drinks aren’t always harmless to teeth

Drinks made with artificial sweeteners or other sugar substitutes may seem like a way to cut down on sugar. But even sugar-free drinks can harm the surface of your teeth if they are acidic.

Also, continuing to choose sweet-tasting drinks may keep you accustomed to very sweet flavors. A “sugar-free” label doesn’t mean you should drink large amounts of the product instead of water.

For everyday hydration, water is the best choice.

5. Avoid sugar before bed; cheese after a meal may be an option

While you sleep, your mouth produces less saliva, which normally helps wash away food and drink. If you have sugar right before bed, your teeth may be exposed to acids for longer. Avoid sugary drinks and snacks before bedtime.

The study also mentions eating a small amount of hard cheese at the end of a meal as one possible way to help protect teeth. Chewing cheese can encourage saliva production, which may help reduce acids in the mouth.

Five things you can do starting today

Choose water as your usual drink
Instead of regularly drinking juice, sports drinks, or soda, choose water.
Set limits on sugary drinks and snacks
Keep track of your overall sugar intake, and watch your portion size when you drink juice.
Check food labels
Read the nutrition facts and ingredients list to see whether a product contains a lot of sugar or syrup.
Choose lower-sugar snacks
Options can include raw vegetables, fruit, nuts, and unsweetened yogurt.
Avoid grazing and sugary treats before bed
After eating, drink water or rinse your mouth. And don’t forget to brush your teeth.

Making a few changes to your food and drink choices can help protect your teeth. The figures and recommendations in this article are based on the study and guidelines mentioned, and recommended limits may differ between countries and health organizations. Ask a dentist or healthcare professional for advice that suits your needs.

Reference

Gunasinghe et al. 2026 Dietary Advice in Dental Practice for Young Adolescents to Prevent Dental Caries: A Scoping Review. International Journal of Paediatric Dentistry, 2026; 0:1–13

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