Am horribly old but can confirm that until recently - blame adverts/marketing if you like, but I think it's more complex - childhood snacks simply were not a thing.
We had breakfast (porridge, cereal or toast) then, if thirsty, very dilute squash mid morning (if at school it was compulsory milk, which I loathed), then lunch ('proper' main course eg stew with potatoes and green veg in winter or ham/egg/cheese salad in summer, followed by a fruit-based pudding).
Then after school/at c 4pm 'tea' = a slice of cake or else toast, butter and jam/honey/marmite/ processed cheese spread (!! horrors, but my childhood favourite) plus more dilute squash or milk/milky tea.
Supper was something like welsh rarebit, beans on toast, scrambled eggs, baked potato and grated cheese, bubble and squeak etc etc with an apple, orange or banana for pudding. If, before bedtime, we said we were hungry then we might get a milky drink (more horrrors to me) and a couple of biscuits - digestives, rich tea or somthing plain but crispy called 'Lincoln' that I don't think exists today.
One summer, we were living by the seaside and I can remember my mother saying to us 'you can have an ice cream every other day OR you can have pocket money, but not both. ' We were genuinely free to choose.
Looking back at photos we were slim but not skinny, and have survived in good health for many decades.
I KNOW that conditions today are much more complicated, but as a child I can never recall feeling really hungry and never, ever deprived.. I suppose it depends on what you are used to. We simply were not used to the idea of 'snacks'. But then our parents never had to contend with the pressure of supermarket displays/junk food advertising. Or the 'me me me' culture.