睡眠不足帶給你的不僅僅是肥胖(圖)
How much sleep is enough? If you get less sleep than the ideal amount but you feel fine, could you be damaging your health anyway? Are we getting less than we used to? Recent research provides some surprising answers。
美國《新聞週刊》撰文：多長時間的睡眠時充足的？如果你的睡眠時間比理想的睡眠時間少，但你感覺正常，這是否仍會損害你的健康？我們的睡眠時間比過去少了嗎？最近的研究提供了一些令人吃驚的答案。
Adults typically need seven to nine hours of sleep each night to feel fully rested and function at their best. However, Americans are getting less sleep than they did in the past. A 2005 National Sleep Foundation poll found that Americans averaged 6.9 hours of sleep per night, which represents a drop of about two hours per night since the 19th century, one hour per night over the past 50 years, and about 15 to 25 minutes per night just since 2001.
成年人通常每晚睡7到9個小時才能感到恢復徹底、狀態良好。然而，美國人的睡眠時間與過去相比越來越少。全國睡眠基金會在2005年的一次調查中發現，美國人平均睡眠時間爲每晚6.9個小時，與19世紀相比，每晚減少約2小時，與50年前相比，每晚減少1小時，甚至與2001年相比也減少了約15至25分鐘。
Unfortunately, we are not very good at perceiving the detrimental effects of sleep deprivation. Researchers at the University of Pennsylvania restricted volunteers to less than six hours in bed per night for two weeks. The volunteers thought they were functioning relatively normally. However, formal testing showed that their cognitive abilities and reaction times progressively declined during the two weeks. By the end of the two-week test, they were as impaired as subjects who had been awake continuously for 48 hours。
遺憾的是，我們沒有很好地意識到睡眠不足的不良影響。賓夕法尼亞大學的研究人員要求志願者在兩週時間內每晚睡眠時間少於6小時。儘管這些志願者在兩週後認爲他們的身體運轉相對正常，然而，測試表明，兩週時間裏，他們的認知能力和反應時間逐漸下降。到測試結束時，他們健康受損程度與那些48小時不睡覺的實驗對象是一樣的。
Moreover, cognitive and mood problems may not be the only consequences of too little sleep. Researchers at the University of Chicago have shown that too little sleep changes the body's secretion of some hormones. The changes promote appetite, reduce the sensation of feeling full after a meal, and alter the body's response to sugar intake—changes that can promote weight gain and increase the risk of developing diabetes。
不僅如此，睡眠過少的後果可能不只是認知能力和情緒問題。芝加哥大學的研究人員已經證明，睡眠過少能夠改變體內某些激素的分泌。這些變化會促進食慾，削弱對寶飽食的感覺，並改變身體對糖類攝入量的反應，導致體重增加，增加患糖尿病的風險。
A study by Susan Redline and colleagues at Case Western Reserve University School of Medicine showed an inverse correlation between sleep duration and obesity in high-school-age students. The shorter the sleep, the higher the likelihood of being overweight, with those getting six to seven hours of sleep more than two and a half times as likely to be overweight as those getting more than eight hours。
由凱斯-西部保留地大學醫學院的蘇珊-雷德蘭及其同事進行的一項研究顯示，高中生的睡眠時間與肥胖程度呈反比。睡眠時間越短，超重的可能性就越大，睡眠時間爲6到7個小時的學生身體超重的可能性事睡眠超過8小時的那些學生的2.5倍以上。
The good news is that these effects can be reversed by getting an adequate amount of sleep. The University of Chicago study on sleep duration and appetite found that allowing the study subjects to sleep 10 hours for two consecutive nights returned the hormones to normal levels and lowered hunger and appetite ratings by almost 25 percent。
好消息是，充足的睡眠可以抵消這些影響。研究發現，讓實驗對象連續兩天睡10個小時可以把激素水平恢復到正常，飢餓感和食慾水平下降近25%。
