Think back to your most productive workday in the past week. Now ask yourself: On that afternoon, what did you have for lunch?
When we think about the factors that contribute to workplace performance, we rarely give much consideration to food. For those of us battling to stay on top of emails, meetings, and deadlines, food is simply fuel, but food has a direct impact on our cognitive performance, which is why a poor decision at lunch can derail an entire afternoon.
Here’s a brief rundown of why this happens. Just about everything we eat is converted by our body into glucose, which provides the energy our brains need to stay alert. When we’re running low on glucose, we have a tough time staying focused and our attention drifts. This explains why it’s hard to concentrate on an empty stomach.
So far, so obvious. Now here’s the part we rarely consider: Not all foods are processed by our bodies at the same rate. Some foods, like pasta, bread, cereal and soda, release their glucose quickly, leading to a burst of energy followed by a slump. Others, like high fat meals (think cheeseburgers and BLTs) provide more sustained energy, but require our digestive system to work harder, reducing oxygen levels in the brain and making us groggy.
Most of us know much of this intuitively, yet we don’t always make smart decisions about our diet. In part, it’s because we’re at our lowest point in both energy and self-control when deciding what to eat. French fries and mozzarella sticks are a lot more appetizing when you’re mentally drained.
Unhealthy lunch options also tend to be cheaper and faster than healthy alternatives, making them all the more alluring in the middle of a busy workday. They feel efficient. Which is where our lunchtime decisions lead us astray. We save 10 minutes now and pay for it with weaker performance the rest of the day.