The test subjects were given either a medium or large tub of popcorn, which was either fresh or a gag-worthy 14 days old.

The stale popcorn eaters scoffed 34 per cent more from a big tub than those who received the medium tubs, even though they thought the popcorn tasted bad.

The upside, according to lead researcher Brian Wansink, is that "supersizing" portions of unsexy but healthy foods, like vegetables, may encourage people to eat more of 'em.