I preface this by saying my son is nearly 9 and has only really been allowed anything fizzy in the last year and it will be on occasion only. Because we are new to it and we don't drink much of it in my house, can anyone please confirm for me - are they better to have the full fat or zero sugar versions? Seen lots of articles saying they shouldn't have sweeteners, but the alternative being suggested is water there, rather than the full fat version of the drink.