What is the right age to feed sweets and chocolates for kids?

I would say up to your comfort level. My #1 diet was VERY strict as he gets sick too often that I'm restricting all sweets, biscuits, chocolates out of his diet. Only until about 4yo does he have them on and off depending on my mood. Bcos my boy tends to be on the heaty side so I have to really control his diet else sickness will come looking for him. You will know ur kid body, so it's up to you to judge to give or not.