There was a day where I determined to eat 10,000 calories in a day on purpose. That was Christmas Day in 2016. It was the ultimate "cheat day". Three gigantic meals interspersed with snacks of Christmas cookies, cheesecakes, nuts, cheeses and crackers, scallops wrapped in bacon. Then the alcohol. Nearly an entire bottle of Frangelico liqueur (before noon) and then Madeira, port wine and amaretto. I generously counted the calories so might actually have been only around 8,500 or so - but it was a lot of food and drink, I'll tell you that. I pretty much ate and drank that entire day. Christmas dinner included roast duck, stuffing made with a dozen eggs, sweet potato casserole with pecans, creamed corn and heavily buttered roasted brussels sprouts.
No, I don't weigh 1,000 pounds. I had spent most of that year losing weight and that Christmas Day was my reward - plus I was celebrating Trump's election. I spent the next eight days hiking in the woods to make up for it!
When I was young, I was slender. I was also an athlete and I could eat far far more than I can now. I would guess maybe a third of what I ate then.
My nephew and his cousins (all teenage boys) used to have a contest on Thanksgiving Day. They’d weigh before and after dinner. Whoever gained the most weight won.