Imagine drinking a sensible fruit-and-protein powder smoothie. Now stop a minute, clear your mind, and imagine you’re drinking a luscious milkshake made with premium ice cream — you know, something really rich and creamy. Which one would make you feel fuller?
I know what your answer is (same as mine when I did this thought experiment). But the real (and surprising) answer is, the shake that makes you feel fuller in real life depends on what you think you’re drinking, not on what you actually are drinking. And that suggests an intriguing way that we can all use psychology to sidestep overeating.
In a clever study exploring the mind’s ability to control how the body responds to food, Yale University doctoral candidate Alia J. Crum gave an identical 380-calorie milkshake to two groups of people, telling one group it was an indulgent 620-calorie shake… and the other that it was a sensible 140-calorie shake.
It was the same drink, but it brought wildly different results in the two groups, not only mentally, but also physically. When researchers took blood samples from each participant and measured his/her level of ghrelin, the body’s “hunger hormone” (the higher the level, the hungrier you feel), they found lower levels in the “high-fat shake” group — as low, in fact, as if they actually had consumed the high-fat drink — than in the “low-fat shake” group. And remember, they were all drinking the same shake! “Mind Over Milkshakes,” as the study was dubbed, was published online recently in Health Psychology.
What does this tell us? In short, Crum said, it tells us that the gut can be tricked into feeling full or feeling unsatisfied depending on what people believe they’re eating.
Crum was not surprised by the fact that the mind-set produced physiological effects — it’s well-known that emotions affect us physically — but she had expected the exact opposite of what happened. “Originally we assumed that thinking the shake was ‘sensible’ would be better for the body. Instead, we found that thinking the shake was ‘indulgent’ was better,” because it left people more satisfied.
Can we trick our brains into thinking a food is indulgent when we know it’s not? Yes, Crum said, as long as we redefine what indulgence means — and infuse a celebratory feel to traditional, minor excesses, such as allowing ourselves a small side order of French fries, one slice of pizza and even an occasional milkshake.
Taking extra time for a leisurely meal is an indulgence, Crum notes, as is focusing on tasty ingredients in healthy foods. Even a salad can be turned into something indulgent, Crum said, if we make a point of seeing the cheese, nuts, croutons or specially made dressing as part of a real treat. “I don’t think we have to trick the mind into thinking food is higher or lower in calories,” Crum told me. “Instead of focusing on how much we are eating, we should focus on stopping and appreciating the food, allowing yourself to have the sense that whatever you eat is something special and more than enough.”
We all know the old adage “mind over matter,” and yet we seldom marshal the determination to do what we know we can do — and that is to realize the power we have to make changes. Just say to yourself, “Mind over milkshake”… take the time to really enjoy everything you eat or drink… and see what happens.
Alia J. Crum, doctoral candidate, department of psychology, Yale University, New Haven, Connecticut.