A look at how portion sizes have changed in the US over the years.
We don't have to eat those extra 360 calories in the tub of popcorn, but that's easier said than (not) done. Studies indicate that when given food in larger containers, people will consume more. In a 1996 Cornell University study, people in a movie theater ate from either medium (120g) or large (240g) buckets of popcorn, then divided into two groups based on whether they liked the taste of the popcorn. The results: people with the large size ate more than those with the medium size, regardless of how participants rated the taste of the popcorn.