I always hear this idea that people nowadays can't go long without eating/eat too many snacks.
I find that a bit strange because growing up my mum always made 'elevenses' in the morning and 'tea' (as in sandwiches, cakes etc) in the afternoon alongside 3 meals a day. My grandparents had supper too.
None of us were/are overweight. I don't have snacks in the day, myself everyday but I do sometimes if I'm hungry in the afternoon.
In my opinion it is the quality of food that is important (it was all fresh home made food) and maybe the portion size too.