Give the punters more food and they will overeat - even if the meal doesn't taste good, according to a study by Cornell University in the US, which focused on the popcorn consumption of 158 movie-goers.

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.