Monday, May 02, 2011

Food size labels

This is why you read my blog. Here is a great example of the value I give you for your time!

A recent study found some results that all of you NEED to know. It's subtle, but powerful - and may explain the obesity epidemic we are facing.

When a food item is labeled "large" it increases how big we perceive it to be. So our internal schema is that it is "a lot of food" so we eat a smaller percentage of it before being satisfied (this satisfaction is some combination of physical satiety and psychological hedonic feelings).

When it is labeled "small", the opposite happens. We perceive it to be smaller, so we eat more of it before being satisfied.

This effect was so powerful that it caused full reversals. People estimated the size of an 8-oz package of nuts (or oreos or sandwiches) that was labeled "large" as being bigger than a 10-oz package of the same item labeled "small."

The presence of nutrition labels or volume labels (quantitative labels such as 8-oz) didn't eliminate the effect. We ignore those. We also ignore more reliable indicators when we have low motivation to be correct or when we are in a rush.

The only time we take care is when we have a specific reason for accuracy (a strict diet) and even then the effect is reduced - not eliminated.

So ignore the size label. Assume everything is large. That popcorn you get at the movie theater - it has 2000 calories of butter, even if it is labeled "medium."