Can the fat content of just one meal affect our concentration? According to new research, it can!

We all know about sugar’s ability to send our energy crashing, along with our ability to focus. Ever try to get some work done after a high-carb meal, but instead, sink into the couch? Want your child to focus after a too-big bag of candy with friends? Seems impossible. Surprisingly, new research suggests that blood sugar crashes aren’t the only contribution to attention, but that saturated fat intake can have a deleterious effect on focus and attention as well.

Saturated fat is “bad” fat or the fat in food that contributes to heart disease and elevated circulating cholesterol levels. Saturated fat is found in processed foods, animal proteins like dark poultry, red meat, fatty cuts of pork and lamb as well as dairy. The dietary guidelines recommend consuming no more than 10% of daily calories from saturated fat, though the American Heart Association recommendation is lower, aiming for 5-6% of calories¹.

A 2020 study published in the American Journal of Clinical Nutrition sought to examine the effects of saturated fat intake on cognitive performance². The researchers, out of Ohio State University, looked at the immediate impact of high saturated fat meals on cognitive performance tests in 51 women. Subjects were given standardized, balanced meals for the 3 days prior to the study period, and then baseline blood samples were analyzed for levels of endotoxemia. Endotoxemia is a potential biomarker of “leaky gut,” where byproducts of digestion pass through the permeable gut lining and into the blood. Researchers postulated that endotoxins independently predicted poor cognitive performance, which could be compounded by saturated fat intake.

The participants were then given the research meal, containing a whopping 60g of fat, coming from either saturated fat or polyunsaturated fat. The researchers compared the resulting impact on cognitive function in both meals through a test that measures attention, concentration, and reaction time.

After the high saturated fat meal, women were less able to perform on the “detectability” measure of the cognitive test, where they needed to distinguish established targets from non-targets. Women with higher levels of endotoxins at baseline were less able to maintain attention and had slower reaction times on exam, no matter what the experimental meal was.

What does all this mean? One extremely high-fat meal can have hours-long negative impact on our focus and attention²! When it comes to the composition of our meals, it’s not just the long term impact, but the immediate and short term impact as well. Conversely, the relationship between saturated fat intake and endotoxins suggested that the effects of leaky gut are more influenced by long term dietary habits and less so by one individual meal². This reinforces that of course,  positive dietary choices and proper digestion have a lasting impact on our overall health and cognitive function.

While fat isn’t often associated with concentration and attention in the way carbs are, the fat content of a meal can negatively affect our post-meal performance. Our recommendation? Aim to keep saturated fat intake under 10% (and even 5-6% when possible), and lookout for signs of post-meal fatigue. It could be a sign to make some dietary changes!

References:

• [1] “Saturated Fat.” https://www.heart.org/en/healthy-living/healthy-eating/eat-smart/fats/saturated-fats
• [2] Madison, Annelise A et al. “Afternoon distraction: a high-saturated-fat meal and endotoxemia impact postmeal attention in a randomized crossover trial.” The American journal of clinical nutrition vol. 111,6 (2020): 1150-1158. doi:10.1093/ajcn/nqaa085