In the book he compared a European– namely French– eating style to an American style. The main difference is, though the French eat food that's just as fatty as that found in the American cuisine, the French as a culture have learned to eat until they are no longer hungry vs. Americans having learned to eat until they're full. Americans also tend to use external cues to tell them when to stop eating. The plate or bowl isn't yet empty. People continue to serve more food. Or Americans just eat until the tv show or movie they're watching is over…etc.
Based on these cues five things that contribute to mindless eating are
1) People eat more when you give them a bigger container. Shown by a movie popcorn experiment.
2) Thinking something is good will lead one to eat more of that food. The reverse is also true. There was a baby feeding study done where it was shown that the caregiver heavily influenced what a baby did or did not like to eat within a remarkably short time span. I think the example used was baby food carrots but it could have been anything. One caregiver who didn't like carrots managed to subconsciously convince the baby to not like "carrots" too. The baby picked up on the caregiver's stink face [yes, that's the scientific term] while being fed the "carrots." Magically the baby began to reject that food within a couple weeks.
3) When food's in front of someone they are more likely to eat it regardless of the amount.
4) People tend to base "being full" cues on volume of food eaten, not calories.
5) When a portion size is increased or decreased by a small amount, up to 20% one likely won't notice a difference in fullness either way. Beyond that it gets very noticeable.
Other highlights include
Re-engineering your environment.The more hassle it is to eat the less we eat, shown by shelled nuts vs almond-in-shell experiment plus a snack proximity experiment.
Cons of wholesale (club store) grocery shopping. Customers end up buying way more than they'd buy under normal circumstances and then feel the need to consume all of it to make it worth the purchase.
Normal vs. obese dining habits. Obese people are much more likely to use forks in a Chinese restaurant.
Also, the more television you watch the more likely you are to be overweight. His studies find that people tend to mindlessly snack while watching tv, even if not hungry.
Even those who try to pay attention to what they eat are not necessarily better off than the rest of the country because marketers, grocery stores, theatres, and restaurants and any number of parties continually use psychological tricks to mess with those trusty external cues that will dictate how much one will eat and we are horrible about estimating how much we've already eaten. Read this book if you want to learn how to combat mindless eating and who knows, you could mysteriously be ten or fifteen pounds lighter by this time next year with not much more effort on your part.