As a child, I was told to go and play outside. In other words, get off the couch and leave the house.
I had to ask before I opened the refrigerator or took something from the pantry.
Many times I was told to wait for dinner.
We drank water not soda when we where thirsty.
Now, I believe children have constant access to snacks and sodas.
They do not go outside and remain inside the home.
I was brought up pretty much the same
TV was restricted to news, live sport (very occasionally), Saturday/Sunday mornings and if we were lucky, the occasional Saturday night film. For the rest of it, we had to find something to do ourselves. "Mum, I'm bored" was met with "Then find something to do" or "Then be bored".
If we were thirsty, it was water, or sometimes juice (real juice, nor cordial).
Snacks, if it wasn't too close to lunch or dinner time, were fruit, which is still currently cheaper than other snacks. An apple is currently about $0.50, a kiwifruit about $0.30-0.40. A chocolate bar, on special, is about $1.00, or you have to buy 3 for $3.00 (Hey, it's cheaper if you buy more, even though you're going to eat them all at once anyway).
I also think a big thing is the energy drinks. The ones loaded with sugar and caffeine, plus taurine and whateverthehellelse they put into it. You can pick up a half-litre can of this stuff for about $3 where I live, and because it's in a can you can't reseal it, so you HAVE to drink it all at once if you don't want to waste it. And I see kids as young as 10 buying these things, while it clearly is labelled "Not suitable for children, pregnant or lactating women, or caffeine sensitive persons". I'm curious as to what's so physically demanding that they require these drinks! I thought coke was bad enough!