As you return to your work after eating lunch, you may wonder: Why am I so sleepy? Whether you use words like drowsiness, sleepiness, tiredness, or fatigue to describe this mid-afternoon lull, why does it occur? Well, it may actually relate to a natural dip in the circadian rhythm.
It is normal to feel a little sleepy after eating lunch. Some people may mistakenly think that it relates to the consumption of food.
In particular, some believe that there is a significant shift in blood flow from the brain to the stomach or gastrointestinal tract to aid in digestion. Although this sounds plausible, it doesn’t really make that much sense. If this were the case, why wouldn’t we feel just as sleepy after eating a large breakfast or after dinner? The truth is that this sleepiness is unrelated to meals and is due to another cause.