Willpower may be a fraught concept when it comes to obesity and how best to address it: Not all who are obese lack willpower; but most who lack willpower in these days of food plenty will eventually struggle with their weight. So a new study looks at what our brains are doing as we make choices between healthy and unhealthy foods, and what factors will nudge it -- and us -- to exercise a little more willpower. The study's findings: a gentle reminder from outside -- a little plug for the healthy stuff -- can help.
When people who regularly make healthy eating decisions look at food, their brains respond differently from those of people who routinely succumb to dietary temptation. Brain scientists who explore human decision-making have mounting evidence that when we give greater weight to more distant rewards -- such as health -- than to shorter-term pleasures (tucking into a bowl of ice cream), the dorsolateral prefrontal cortex is typically acting in concert with the ventromedial prefrontal cortex. When we succumb as well, the ventromedial prefrontal cortex is at work -- but without the more sober input from the lobe next door.
So how to prompt the brain's willpower mechanisms to action? Among 33 hungry young adults who were not trying to lose weight and who were offered a host of food choices while lying in a brain scanner, "cues that direct attention to the health features of food" nudged them to take health benefits more heavily into account.
The subjects were given two seconds to choose which of two foods -- one more and one less healthy -- they would like to eat, with the promise that they would be served one of many choices they made after the brain scan. In some runs, subjects were asked to consider the healthfulness of the food before choosing. In others, they were prompted to consider tastiness. In other runs, subjects were given no prompts to guide their choices.
When prompted to consider the healthfulness of the foods they preferred to eat, subjects were more likely to choose healthy foods even if they didn't consider them very tasty than they were to choose foods they considered very tasty but not healthy. And their brain activity showed the patterns of long-term reward preference that researchers were looking for.
It's an effect that has driven a multibillion-dollar food-advertising industry -- that appealing messages about the deliciousness of a product will prime consumers' choices. And as public health officials grapple with how to get people to choose healthier fare, they've taken some pages from that book -- devising labeling schemes that would draw consumers' attention to the healthy attributes of a grocery item and launching public service announcements about the benefits of healthy eating.
If those public health campaigns had the same budgets that less healthy foods do, they might make some headway.