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Yes. Simple sugars that bacteria process to make acid, that eats into the tooth.

Our mouths aren't sterile, so there is always some plaque. Most meals, there is some sugar, even if low carb. Most fruits and vegetable contain sugars. When raw, they won't cause decays but cooking can caramelise and make simple sugars.

Sugar, plaque plus time is what's needed. Cut down on any of the three and there's less decay. It's also worth bearing in mind that decay is a back and forth process. Every meal it advances. Then saliva repairs before the next meal. Too much sugar and not enough gaps between meals (snacks) and decay becomes a cavity.