Ever wonder why food can seem irresistible when you’re having a drink or two?
So do brain scientists. Now they have a clue.
Researchers at the Indiana School of Medicine studied what happens in the brain when the “aperitif effect” kicks in—the scientifically well-known tendency to consume more calories if you’ve also been drinking…even moderately. For men, the extra calories are more than 400, while for women they are about 300. Some of those extra calories come from the booze itself, but about 40% come from eating more food.
The new research suggests that having a drink or two lets our brains do what comes naturally—pay attention to food.
HOW ALCOHOL UNLEASHES ANIMAL APPETITES
The study: After breakfast, 35 normal-weight women who were not vegetarians (you’ll see why when you see what they got for lunch) were given an IV drip that contained either a saline solution on one day…or enough alcohol to make them mildly buzzed on another day. According to the study, the subjects reported “a clear subjective sense of alcohol exposure.”
Why intravenous? To skip gut effects of alcohol and hone in on what’s going on just in the brain. Why only women? To make sure that differences in food preferences were due to the alcohol, not gender differences. Future studies may look at men.
Then, the smell test: While hooked up to MRI brain scanners, the women took in the tantalizing aromas of food—Italian meat sauce, roast beef—and then the pleasant nonfood scent of a Douglas fir tree.
Next, lunch was served, either pasta with Italian meat sauce or noodles with shredded beef in gravy. The women were asked to rate their hunger…and were allowed to eat as much as they wanted.
Results: On the boozy day, they didn’t think they were any hungrier than on the sober day. Hunger hormones actually went down (possibly due to calories in the alcohol). And yet…the women ate on average about 7% more food on the alcohol day.
Why? One clue lies in a part of the brain called the hypothalamus, which affects appetite and metabolism. On the sober day, brain images looked the same when the women smelled the food odors as when they smelled the fir tree odor. But when they had alcohol coursing through their veins, the hypothalamus lit up only for the food smells.
Why did the women lose interest in a pleasant outdoorsy smell when they were a little buzzed? Researchers speculate that the shift of attention toward food is a remnant of an evolutionary instinct. Alcohol reduces inhibitions so that our “animal instincts” kick in and we focus on what matters for survival…such as food.
HOW TO MAKE THE APERITIF EFFECT HELP YOU
Now that you know for sure that alcohol makes you super-receptive to food, if you’re watching what you eat, pay closer attention to what and when you drink. For example, if you’re going to a party, eat a filling, nutritious snack beforehand (before you drink any alcohol), intersperse a low-alcohol drink with a nonalcoholic one and pay special attention to the tendency to overeat. Ditto for having a cocktail at a restaurant. To make sure that it doesn’t lead to overeating the bread and butter that magically appears at your table, why not ask the server to take the bread back?
But you don’t always need to fight biology. Sometimes, it’s just fine to enjoy a glass of wine or a frosty mug of beer, and bask in the knowledge that it’s helping you relish your meal a little more keenly. That’s healthy, too.