In addition to all of the points made above, I think that nowadays, we see hunger as something to be avoided at all costs - a condition to be "medicated" with snacks as soon as it shows any sign of appearing.
When I was a child, if you didn't eat at mealtimes, you had to wait until the next. On the whole, we've lost sight of normal eating patterns. Snacks such as crisps and chocolate used to be a treat, eaten in moderate portions, rather than a staple food, available in increasingly huge packs.
Having said that, I find very irritating the nutritional advice and policing which clearly assumes that everyone is overweight. When pregnant (and very slim), I was given the Emma's Diary type nutrition advice pack which suggested that a cottage cheese salad was a sensible lunch for a pregnant woman; an overweight one, maybe!
I also resented the packed lunch police at my DS's primary school. He was 3rd centile for BMI and yet if he took anything containing fat or sugar (eg biscuits), words were had. Nothing was said to the parents of overweight children, who turned up at the school gates with sugary fatty snacks.