Advanced dental care

What sugar does in your blood and in your mouth — and why meal frequency matters for your teeth.

You have probably heard: "No more than 7 eating moments per day." But why? What happens in your body and in your mouth when you keep having snacks?

The answer is more interesting than you might think. Two things happen simultaneously: something in your blood and something in your mouth. And both are connected.

What happens in your blood?

Imagine you eat a chocolate bar or drink a glass of cola. The sugars immediately enter your bloodstream. Your blood sugar spikes.[1]

Your body thinks: "Oops, too much sugar!" and releases insulin — a hormone that brings the sugar back down. But often it overshoots. Your blood sugar drops too low.

And then what happens? You feel hungry or weak. Your body is calling out: "Give me sugar!" So what do you do? You reach for something sweet again. Up goes the blood sugar. Then down again. It is a rollercoaster your body is not happy about.

Sugar gets stored as fat

Your body uses sugar for energy in your muscles. But when it gets more than it needs, it has to go somewhere. Your body converts that extra sugar into fat and stores it.[2]

Every time you snack or drink a sugary drink, your body gets more sugar than it needs. And every time, a little gets stored as fat. That is how simple it is.

The difference with a sandwich
In a sandwich, pasta, potatoes or rice there is also sugar, but stored as carbohydrates.[3] These are broken down slowly. Your blood sugar rises calmly — no rollercoaster. You get enough energy and after a few hours you feel normally hungry again. Because the sugars are released slowly, your body can burn them neatly without an excess that has to be stored as fat.

And what happens in your mouth?

When you eat or drink (except water), the pH in your mouth drops. In acid, the enamel of your teeth partially dissolves. This is called demineralisation.[4]

Fortunately, saliva acts as a hero. It neutralises the acid and brings minerals back into your teeth (remineralisation). But saliva needs time: it takes approximately 20 to 60 minutes for the acidity to return to normal.[5,6]

The problem with constant snacking
If you keep having a sweet every now and then or sipping a fizzy drink, your saliva never gets a chance. The mouth is constantly acidic. Demineralisation wins over remineralisation. And over time you get cavities.[7]

Why are fizzy drinks especially harmful?

Cola and iced tea contain acid: cola has phosphoric acid and iced tea has citric acid. Both make the mouth more acidic.[8]

Phosphoric acid is neutralised slightly faster by saliva than citric acid. But do not be fooled: both are bad for your teeth if you drink them throughout the day.

And diet drinks? Not good either. Even without sugar, the acid is still there. Your teeth still dissolve.[9,10]

Energy drinks are even worse

Energy drinks contain not only a lot of sugar and acid, but also caffeine and taurine.[11] Taurine is an amino acid that, combined with caffeine, can raise your heart rate and sometimes cause palpitations.[12,13]

The combination of high doses of caffeine (sometimes more than 150 mg per can) and taurine can be dangerous, especially if you drink a lot of them. There have been documented cases of cardiac arrhythmias in people who drank large quantities of energy drinks daily.[14]

And for your teeth? Energy drinks are extremely acidic. The pH is often between 1.5 and 3.3 — almost as acidic as stomach acid.[15] Tooth enamel dissolves very rapidly.

Sports drinks seem healthy, but...

Sports drinks are often perceived as healthy. But be careful: they contain a lot of sugar, salt and citric acid.[16] If you exercise intensively and genuinely need fluids with electrolytes, they can be useful. But if you drink them all day without exercising, you get the same problems as with regular fizzy drinks.

The wisdom of 7 eating moments

Now you understand why 7 eating moments is sensible. Not because 8 is magically bad — 8 or 9 moments won't kill you. But because you give your body and your mouth a rest.

Between eating moments:

  • Your blood sugar can stay stable
  • Your saliva can neutralise the acid
  • Your teeth can recover
  • You stay off the rollercoaster

Can you manage 7 eating moments?
You don't always have to. The point is to understand what is happening. When you know why something is wise, you can make your own informed choice. Nobody is perfect. But if you can manage fewer eating moments per day, that is a gain for your teeth.

What can you drink between meals?

Water. Plain water. No sparkling water with flavourings, no cordial, no fruit juice. Just plain water.[17]

Water does not make your mouth more acidic. It even rinses your mouth a little. Tea and coffee without sugar are also fine — but keep it simple: water is best.

The message

Give your body rest between eating moments. Drink water. Eat regular meals with slowly-digested carbohydrates. Your blood sugar stays stable, your saliva can do its job, and your teeth stay healthy.

It really is that simple.

Scientific references
  1. Ludwig DS. (2002). The glycemic index: physiological mechanisms relating to obesity, diabetes, and cardiovascular disease. JAMA, 287(18):2414-2423.
  2. Stanhope KL, Schwarz JM, Havel PJ. (2013). Adverse metabolic effects of dietary fructose. Current Opinion in Lipidology, 24(3):198-206.
  3. Jenkins DJ, et al. (1981). Glycemic index of foods. American Journal of Clinical Nutrition, 34(3):362-366.
  4. Lussi A, Jaeggi T. (2008). Erosion — diagnosis and risk assessment. Clinical Oral Investigations, 12(Suppl 1):5-13.
  5. Firbyanto R, Widyastuti A. (2018). Effect of brushing the teeth before and after meals on salivary pH. Journal of International Oral Health, 14(2). "Salivary pH returns to neutral within 30-60 minutes after eating."
  6. Dehghan M, et al. (2016). Neutralizing salivary pH by mouthwashes after an acidic challenge. Journal of Investigative and Clinical Dentistry, 7(1):24-28.
  7. Luminé Dental (2024). Is Your Saliva's pH Damaging Your Teeth? "It takes a minimum of 20 minutes after eating for saliva to return to healthy levels."
  8. Ehlen LA, et al. (2008). Acidic beverages increase the risk of in vitro tooth erosion. Nutrition Research, 28(5):299-303.
  9. Colgate Oral Care Center. Sugar Free Drinks: Safe for Teeth? "Diet sodas cause about the same amount of dental erosion as regular sodas."
  10. Rodgers MM, von Fraunhofer JA. (2003). Diet soda vs. regular soda: effects on dental enamel erosion. University of Michigan.
  11. Higgins JP, Tuttle TD, Higgins CL. (2010). Energy beverages: content and safety. Mayo Clinic Proceedings, 85(11):1033-1041.
  12. Seifert SM, et al. (2011). Health effects of energy drinks on children, adolescents, and young adults. Pediatrics, 127(3):511-528.
  13. Gray B, et al. (2012). Consumption of energy drinks: a new provocation test for primary arrhythmogenic diseases? International Journal of Cardiology, 159(1):77-78.
  14. Parikh A, et al. (2017). Energy drinks and cardiac arrhythmias. Journal of Addiction Medicine.
  15. Dr. Sylvain Chamberland, Orthodontist (2023). Energy Drink and Dental Erosion. "Energy drinks have a pH ranging from 1.5-3.3."
  16. Coombes JS. (2005). Sports drinks and dental erosion. American Journal of Dentistry, 18(2):101-104.
  17. Colgate Oral Care Center (2024). How To Rebalance The PH Of Your Mouth. "The best option for maintaining neutral oral pH is plain water."

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