I took this from a discussion in another thread as not to derail the topic :
So when did the half a cow/pig/chicken meals washed down with a gallon o’ drink of your choice? start being common
I’m 45 and I recall it being a gradual thing in my lifetime. I remember as a kid that sodas typically came in a 12 oz can. Even as a teenager who ate like a horse, a McDonalds hamburger was enough and a Big Mac was for when you were ready for a nap afterwards. Then sodas came in a 20oz bottle in the early 90s, then the 1 liter in the late 90s and I remember thinking how outrageous that was because it was 1/2 of a 2 liter bottle. So I am with the others in that it wasn’t a particular point in time, but it was a gradual increase.
Also, when I was younger, a fast food joint was an occasional treat, or an in a hurry so we have to grab something quick thing, not a daily lunch routine. Same with pizza. That was a once every couple of weeks thing, and I remember as a kid, we would order a single large pepperoni pizza, my dad would have two slices, me two slices, and my mom and sister one each. Sometimes my dad or I would only have one slice and have leftovers for the next day.
Today I see people ordering a large pizza for most of the members in the family, each with their own choice of toppings, and not very much left over. But again, that didn’t happen over night. I think as a society we have become more sedentary and less rooted on how we were taught to eat many years ago.
According to Gin Craze, US portion sizes have been crazy out of control since almost the founding of the country. The book talked about places with lodging + food, since I don’t think they had many restaurants back then.
They still do! 
Belisles was famous for large portion sizes way back in the day. They had a great turkey plate. I miss family run traditional American restaurants. I live in Los Angeles and these restaurants have gone the way of the dinosaur.
I’m 42, and my experience is quite similar. I remember when I was 10, one of my cousins (who was old enough to drive) was taking me on a relatively long trip. We stopped at 7-11, and got a Big Gulp for the two of us to share. We both marveled at how big it was.
When I was in Europe 4 years ago the portion sizes everywhere seemed the exact same. I would order from a family diner their “regular burger” and it looked like a quarter pound with cheese from McDonalds in terms of size. I had various schnitzel dishes around Germany from local restaurants and the portion were right in line with something you’d get from a local diner in America or a chain place like Applebee’s. For sodas they still seemed to just give you a normal 12 ounce can of Coke though, no big cups.
Yes, soda sizes have ballooned. My theory- HFCS. I read a study that said HFCS had a lower “satiety” rating than cane sugar (your Mom was right when she said it would spoil your appetite) . Cokes were 6 or 7oz, Pepsi 12, RC 16.
But then they switched in HFCS and you can (& will) drink more.
I only drink diet and that rarely and I fill the cup to the top with ice, but on a long trip I do like a 32 oz drink. The ice will last for hours.
However, giant steaks were common on the menu back when we ate out when i was a kid. Not that everyone ordered one, but there were there. The german restaurant was famous for large portions.
Us middle class people like large portions as we do not eat out very often, so we want "value’ and often leftovers.
Not a week ago did I watch someone knock back a one pound burger. I’m no angel but that had to have been a big bite. When I buy a ‘pound’ (often more like 1.3 lb) of ground beef (or lamb), it will cover 3-6 meals (like chili vs tacos vs burgers vs pasta sauce). I typically shoot for 140 gram patties for grilled burgers which often winds up being about four with one maybe a little smaller or larger, depending on what I happened to pick up.
Half a chicken’s been common all my life, and I’m nearly 70. And I agree that steaks would be on the menu in various sizes, including huge; and that was before it was polite to ask to take some of it home with you.
The soda’s another matter. Not only did it come in 8 oz bottles, but it wasn’t drunk as a regular beverage, to quench routine thirst; for that children drank water or milk, grownups water or tea or coffee. I agree that soda crept up gradually, both in size and in that (or some other form of flavored drink) replacing water as what you drank when you were thirsty. (The water was tap water, unless you had utterly horrible tap water, and sometimes if you did. I’m still confused by the marketing genius that somehow has gotten lots of people whose tap water is entirely potable to buy bottled water instead.)
But a standard size one-serving candy bar I’m pretty sure has actually shrunk.
– it occurs to me that another major difference is in how often most people eat at restaurants. Used to be something you did maybe once a week.
First thing I thought of.
Their portions were so over-the-top, and they knew it. They served their half-gallon-sized drinks with a 2’ long straw.
Another place that had enormous portions was the Claimjumper.
Don’t forget Cracker Barrel, my goodness there’s a spot for ya. The place where vegetables go to die soaked in bacon grease and boiled to oblivion. Good fried chikin though.
Even the “salad” is over 1800 calories.
I liked Belisle’s. It was a great place for breakfast after a night of partying. When I worked behind the Orange Curtain, the office was very close and we’d go there for lunch sometimes. I was annoyed when it was closed and torn down for some Disney-related thing.
This video I watched recently seems appropriate here…
Aside from the gigantic sodas, I must admit I’ve never noticed it, nor can I recall anyone commenting on it IRL (which the exception of occasional instances in restaurants). In fact, I only hear people commenting on it here(I believe this is the part where someone chimes in to say they order a to go container with their meal and put half in it before they even start eating).
Unless we’re talking about larger sizes being available to order(?) Then yes, somewhere over the years peoples’ appetites grew to necessitate supersized whatever. But I don’t notice any restaurants giving out extra food.
There’s a family-owned burger joint here that has excellent food, but the portions are ridiculous. The smallest burger they offer is a 1/3 lb, which is too much for me. The portion of fries you get is unbelievable. You could share a single portion with a family of 4 easily. I think it’s such a waste. I bet half of the fries they cook every day get tossed in the trash.
We tried a new restaurant a while back. I was craving a good cheeseburger. The menu bragged about their 1 lb burgers. When the waiter came to take our order I asked if it was possible to get a smaller burger. Nope - only 1 pounders available. The thickness alone of that burger would make me sick. 
I was the one who mentioned the increasing portion sizes in the last thread. There’s a local pizza place where a “normal” order of fries fills up a whole takeout box. A lot of burger places automatically serve an 8 ounce burger and there’s not a smaller one on the menu. Last time I was at Olive Garden I swear they gave me a whole pound of pasta. Or there are sandwich shops where the hoagies have so much stuff on them you can’t even bite it.
I don’t remember exactly when, but restaurants used to make a point of saying their burgers were quarter pound. Then it was a third of a pound, then half a pound. Many places just have one size soft drink instead of smalls and larges.
Of course no one forces you to eat the whole thing but then you either have to leave half of it on the plate and waste food and money, or take it home and hope the leftovers don’t suck.
And I think a lot of us have a “clean your plate” mentality because we were made to as children. I could say a lot about that but it would be yet another thread.
I do know that, at some point in the past, automotive companies had to increase the size of the cup holders in their cars because they weren’t big enough to hold the large drinks. I searched for a time frame but couldn’t find one.
A former chef (restaurant, not fast food) explained it to me this way: Every time a restaurant changes hands, or hires an expert to find out why the place is hemorrhaging money, the expert or new owner’s very first idea is to use cheaper ingredients, then implement portion control (smaller portions). It’s apparently an inevitable cycle for most restaurants.