美国科学家最近在该国医学期刊《内科年鉴》上发表研究报告指出，长期充足和健康的睡眠可能是很好地控制体重的原因之一。

　　据路透社12月7日报道，科学家经研究发现，如果健康的年轻男性连续两晚只睡4个小时，他们体内抑制食欲的激素水平就会下降，同时刺激食欲的激素水平会上升。负责此项研究的美国芝加哥大学医学教授伊夫·考特博士说，尽管还需要进一步研究，但这项新的实验结果显示“如果不缺乏睡眠，那么你将可以轻松地控制食欲并成功地保持或降低体重”。

　　此项实验中研究的两种可以调节食欲的激素分别是“莱普汀”(leptin)和“葛瑞林”(ghrelin)。前者由脂肪细胞分泌，帮助提醒大脑“已经饱了”；后者由胃分泌，使人感到饥饿。实验发现，与连续两晚睡足10个小时相比，连续两晚只睡4小时的年轻男子，体内leptin的水平降低了18%，而ghrelin水平则上升了28%。

　　科学家还发现，缺乏睡眠的男子对自己的食量和“饥饿等级”的评估也平均上升了24%，他们要的食物多是一些甜食，或者炸薯条和坚果之类的咸食，还有淀粉含量很高的面包和通心粉等。考特说，这种与缺乏睡眠有关的激素变化的确切原因还不清楚，这种机制可能与大脑中某个区域有关，在这个区域中神经元对饮食和睡眠都会作出反应。(程瑶)

　　Consistently getting a good night's sleep may be one of the answers to maintaining a healthy weight, if early research findings are correct.

　　The small study found that when healthy young men slept for only fours hours on two nights in a row, they showed dips in a hormone that suppresses appetite, coupled with increases in an appetite-stimulating hormone.

　　On top of that, the volunteers reported being more hungry after their sleep-deprived nights than after nights when they slept for 10 hours.

　　Though more research is needed, the new findings suggest that "if you do not run a sleep debt, you will be able to curb your appetite more easily and maintain or lose weight," study leader Dr. Eve Van Cauter, a professor of medicine at the University of Chicago, told Reuters Health.

　　The two appetite-regulating hormones in question are leptin, which is released from fat cells and helps alert the brain that it's time to stop eating, and ghrelin, which is produced in the stomach and helps trigger hunger.

　　Van Cauter's team found that when the 12 men in their study slept for four hours on two consecutive nights, their levels of leptin were 18 percent lower and their levels of ghrelin were 28 percent higher than they were after two nights of spending 10 hours in bed.

　　The exact reasons for the hormonal changes associated with sleep deprivation are not yet known. According to Van Cauter, the mechanism may have to do with a small area in the brain where neurons respond to both eating and sleeping.