Substances intentionally added to food to produce a desired effect

That is true. For example MSG are added to most Chinese food to make it tasty but actually MSG isn't good for your health because it is an additive that is made chemically. Also juice and many other substances like food coloring are added to food to make it either yummier or prettier but will affect us after years of accumulation. Your question isn't very clear so what are you trying to ask exactly?

Explanation:

age might have something to do with behavior depending on the age because not everyone who is the same age acts the same like 2 year olds could have bad behavior but some won't.

i hope this : )