COLUMBUS, Ohio — The next time you have an important task at hand, researchers from Ohio State have some important advice: don’t eat a particularly fatty meal before you get down to work. Their new study finds that just one meal high in saturated fat can seriously impede a person’s ability to focus or concentrate.
The study compared 51 women’s scores on an attention test after eating either a meal loaded with saturated fat or the same food, only cooked using sunflower oil, which contains unsaturated fat. Test performances were much worse among participants who ate the saturated fat meal.
Besides these findings, researchers were also interested in the effect of “leaky gut” on concentration. Leaky gut is a condition that causes intestinal bacteria to enter the bloodstream. They noted that participants with leaky gut performed poorly on the attention tests, regardless of the type of food they ate.
“Most prior work looking at the causative effect of the diet has looked over a period of time. And this was just one meal – it’s pretty remarkable that we saw a difference,” says Annelise Madison, lead author of the study and a graduate student in in clinical psychology at The Ohio State University, in a release.
It’s worth mentioning that even the sunflower oil-cooked meal was still high in overall dietary fat.
“Because both meals were high-fat and potentially problematic, the high-saturated-fat meal’s cognitive effect could be even greater if it were compared to a lower-fat meal,” Madison adds.
First, participants filled out a baseline assessment of their concentration skills. These tests measured reaction time, sustained attention capabilities, and concentration using a 10-minute long computer program.
The meal that participants ate consisted of eggs, turkey sausage, gravy, and biscuits. Across both groups, the meal contained 60 grams of fat (either saturated fat or dietary fat) and added up to 930 calories. Those food items were specially chosen because they closely recreated the fat content of most major fast-food meals, such as a Big Mac or Whopper meal.
After eating one of those meals, participants took the same test again. Then, a few weeks later, they did it all over again, while eating the opposite meal of what they had eaten the first time.
On average, subjects were 11% less capable of concentrating after eating the meal high in saturated fat. Meanwhile, women with leaky gut (endotoxemia) performed poorly across both experimental groups.
“If the women had high levels of endotoxemia, it also wiped out the between-meal differences. They were performing poorly no matter what type of fat they ate,” Madison explains.
The study’s authors can’t say for sure why saturated fats have this effect, but prior research has noted that fatty foods tend to inflame the entire body, even the brain.
“It could be that fatty acids are interacting with the brain directly. What it does show is the power of gut-related dysregulation,” Madison says.
The study is published in the American Journal of Clinical Nutrition.