Let's put this in the office situation. We all become sleepy after lunch. We need to fight the urge to fall asleep. There is a big problem in this. It's that the productivity instantly drops when you are sleepy. Let's say that you are dozing off for 30 minutes. When your working hour is 8 hours, the actual time spent working becomes 7 hours and 30 minutes. When you are working 22 days a month, it's 30 min x 22 = 11 hours. You lost 11 hours of productivity. If there are 10 staff, 100 hours is lost. It's hard to ignore this as a management.
Before suggesting how not to become sleepy during the day, let's think about how humans feel sleepy. It's because of rapid increase in blood sugar level. When the blood sugar level rapidly increases, humans feel sleepy.
That is, in order for us not to get sleepy, we need to eat food that does not rapidly increase blood sugar level for lunch. Let's avoid rice bowls. Ramen is also not a good choice. Stop eating food with high carbohydrate. Eat vegetables first, suppress blood sugar level from increasing and then eat meat. By doing so, we won't get sleepy after lunch (if you're still sleepy, it's possible to get rid of sleepiness by daringly sleeping with your head down on the desk for 15 minutes).
To improve productivity, we often think of using various tools. However, it is possible to improve productivity just by changing the content of (the order of) your diet.
Above is translation of an article "食事から見る生産性向上" dated December 01, 2017
Translation by Hiroko Matsuda