The gist of this book, which I highly recommend BTW, is that humans underestimate the degree to which they can successfully resist a tempting environment. I completely agree with his conclusion that the secret of mastering our obesogenic environment is not to summon mythical heaps of willpower, but rather to learn how to change our environment to help nudge us toward healthier choices. Over my coming posts, I will try to make it a point to reference the results of some of his experiments as I continue to examine my own nutritional failings as well as my plans to address them.
I'd like to start with one of my favorites. Wansink's belief is that very few people stop eating because they are full. Rather, they tend to stop eating when they receive certain visual or other types of external cues. In one particularly twisted experiment, he asked a bunch of test subjects eat soup until they were full. All of us members of the Clean Plate Club (I'm a charter member) use the existence of an empty plate to signal that we must be full. In his clever soup experiment, Wansink and his conspirators rigged some soup bowls so that they were automatically refilling. His subjects would either get a normal bowl or they would get one that was secretly and automatically refilling. He served soup in a large 18 ounce bowl and asked people to stop when they were full. Here were the results:
- People in the normal -- if 18 oz can be considered normal -- bowl group ate an average of 9 ounces of soup. When asked to estimate how many calories they thought they consumed, they guessed 123. It turns out they actually ate 153 calories. In other words, they underestimated by 24% -- a cautionary tale for us all!
- People in the bottomless bowl group ate an average of 15 ounces (!) or 67% more than the normal bowl group. Apparently a few ate over a quart. When asked how many calories they guessed they had eaten, they replied with an average of 127 -- about the same as the normal bowl group. In fact, they had eaten an average of 268 calories. The underestimated by 111% how much they had eaten.