When sugar meets plaque bacteria, they release acid for around twenty minutes, dissolving minerals from the enamel. Hidden sugars in fruit juice, biscuits, and sweetened tea keep that acid clock running far more often than people realise.
The fix is not zero sugar but smarter timing: enjoy sweets with meals, rinse with water afterwards, and avoid constant sipping and grazing. Give your teeth long acid-free stretches and saliva does the repair work naturally.