We know that behavior change is hard, whether it involves diet or exercise or anything else. But sometimes deceptively simple hacks offer a quicker route to changing a behavior than first seems possible. A new brain imaging study presented this month at the Annual Meeting of the Society for the Study of Ingestive Behavior reveals such a hack for making healthier portion choices. Turns out, it has everything to do with how we talk to ourselves before we start eating.
Researchers recruited participants ranging from normal weight to obese and asked them to think about one of three things while selecting a portion size for lunch: (1) the health effects of the food they were about to eat, (2) their expected pleasure from eating the food, or (3) their intention to stay full from lunch until dinnertime. A control group was asked to choose their portion size without any particular mindset instructions.
The results showed that most everyone, regardless of weight, chose smaller portions when told to think about the health effects of the food. When told to think of pleasure, the obese participants chose larger portions than normal-weight participants. When told to think of fullness until dinner, most participants chose larger portions regardless of their weight. (All of the results were compared against the control condition in which the participants could think about whatever they wanted.)
Brain imaging showed that the obese participants had greater activity in a “taste-processing region of the brain” when thinking about the pleasure of eating the food. When thinking about staying full, obese participants’ brains showed a “blunted response in regions for reward and physiological regulation.”
So while adopting a health-effects mindset helped pretty much everyone make better portion choices, the pleasure mindset seemed to handicap obese participants from making healthier choices. The brain imaging results suggest that outcome is tied to an enhanced sense of how the food will taste.
Thinking about how to eat enough to stay fuller longer (a common way to think at lunch when dinner is still several hours away) encouraged everyone to eat too much. Here again, the brain imaging suggests that obese participants were especially influenced by the mindset.
"This influence of pre-meal mindset on food choices may contribute to the vicious cycle we observe in obesity," said lead study investigator Stephanie Kullmann of the University of Tübingen, Germany. "Focusing on food for pleasure leads to bigger servings and increased brain responses to food reward, while the sensation of fullness is perceived as less satisfying."
The biggest takeaway from this study is also the most obvious: thinking about the health effects of what we’re about to eat is an effective way to curb overeating. Having a little pre-meal chat with ourselves about what the food is going to do to our body is a routine worth adopting.
While thinking about the pleasure of eating isn’t necessarily bad (because who wants to not think about how good something is going to taste?) we should at least be aware that it's not going to help with portion control – and if you’re struggling with obesity, this mindset could make it much harder.
Of all the mindsets, the study suggests that thinking about how to stay fuller longer is arguably the worst, as it directly incentivizes eating more. Just stick with thinking about lunch for the sake of lunch, rather than as a bridge to make it to dinner. A healthy snack in your desk drawer will get you there without a lunchtime calorie catastrophe.
The study results were presented at the 26th Annual Meeting of the Society for the Study of Ingestive Behavior.
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