The size of our plates, soda bottles and candy bar wrappers strongly influence our perception of how much food constitutes an adequate serving. In a recent report published in the journal Psychological Science, researchers claim the rise in obesity over the last few decades is largely due to super sized fast food, restaurant and packaged supermarket portions.

Referred to as unit bias, the researchers carried out experiments offering different sized cups or scoops to see if people would eat or drink more or less accordingly. Sure enough, if you put out a bowl of M&Ms in a lobby with a quarter-cup scoop, people will eat more of them than if you leave out a teaspoon for serving.

The researchers commend companies who've introduced the 100-calorie serving size snack packs, and hope that food industries will begin displaying portion recommendations more prominently on packaging. Dieticians often recommend eating meals on smaller plates to reduce portion sizes.