評論
打印
When you go back to work or class after lunch, why is it so hard to stay awake?
當我們用完午餐回去工作或上課時，為什么很難保持清醒呢？
Although we get energy from food, we also use lots of energy to digest it. Your energy use increases 25-50% as you digest a meal.
盡管我們從食物中獲取能量，但也需要耗費許多能量來消化這些食物。消化一餐就會增加百分之二十五至五十的能量消耗。
With all that action going on in the digestive system, the body sends extra blood to the gut to supply oxygen and other necessities.
有了消化系統內的一系列活動，身體才能源源不斷地將額外的血液輸送到消化道以提供充足的氧氣和其它必需物。
How does the body know when to do this?
身體如何知道何時這樣做？
As food enters the stomach, the intestines secrete substances that dilate, or expand, the blood vessels that supply them with blood.
當食物進入胃，腸道便分泌許多物質，它們使得為腸道供血的血管膨脹或擴張。
As a result, more blood flows to the upper digestive tract, and there’s a bit less to go around to the rest of the body.
結果便是更多的血液流向上消化道，而循環于身體其它部分的血液則相應減少，
That might make your arms and legs and brain feel a little sluggish!
這時你可能感覺渾身懶洋洋的，連大腦也變得遲鈍起來。
At the same time, the small intestine releases a hormone that activates the part of the brain that controls sleep, making you drowsy.
同時，小腸釋放出一種荷爾蒙，它可以激活控制睡眠的大腦區域，讓你昏昏欲睡。
Finally, the natural components in foods can also contribute to the snooze effect. Certain foods, especially carbohydrates, increase production of serotonin in the brain.
最后，食物中的天然成分也會讓你打盹。某些食物，特別是碳水化合物，會增加大腦中血清素的生成。
Serotonin works both to stop sugar craving, and to make you very relaxed. The larger the meal, the more pronounced that feeling can be.
血清素既可以抑制吃甜食的欲望，又可讓你倍感放松。吃得越多，這種感覺就越明顯。
With all of these physiological reasons why we might feel sleepy after eating, a siesta after lunch sounds like a brilliant idea, and maybe after dinner and breakfast too!
鑒于諸多生理原因導致我們餐后昏昏欲睡，也許午餐抑或早晚餐后小憩一會兒是個明智的選擇。
