The negative health effects of sleep shortages during the week can't be changed by marathon weekend sleep sessions,according to a new study.
Researchers have long known that routine sleep deprivation（缺乏）can cause weight gain and increase other health risks,including diabetes.But there are still some people who hope that shutting off the alarm on Saturday and Sunday will repay the weekly sleep debt and remove any ill effects.
The research,published in Current Biology,ruins those hopes.Despite complete freedom to sleep in and nap during a weekend recovery period,participants in a sleep laboratory who were limited to five hours of sleep on weekdays gained nearly three pounds over two weeks and experienced metabolic disruption（代谢紊乱） that would increase their risk of diabetes over the long term.While weekend recovery sleep had some benefits after a single week of insufficient sleep,those gains were wiped out when people returned right to their same sleep schedule the next Monday.
"If there are benefits of catch-up sleep,they're gone when you go back to your routine.They're very short-lived," said Kenneth Wright,who oversaw the research. "These health effects are long-term.It's kind of like smoking once was-people would smoke and wouldn't see an immediate effect on their health,but people will say now that smoking is not a healthy lifestyle choice.I think sleep is in the early phase of where smoking used to be."
Wright said that the study suggests people should prioritize sleep-cutting out the optional "sleep stealers" such as watching television shows or spending time on electronic devices.Even when people don't have a choice about losing sleep due to child-care responsibilities or job schedules,they should think about prioritizing sleep in the same way they would think about a healthy diet or exercise.



What had the researchers already known before doing the new research？ ______

A. The actual benefits of weekend recovery sleep.
B. The harm to health caused by the lack of routine sleep.
C. People's habit of shutting off the alarm during holidays.
D. The relationship between body weight and sleep amount.

Why did Kenneth Wright mention smoking？ ______

A. To call on smokers to completely abandon smoking.
B. To advise people to go to sleep when they want to smoke.
C. To show people have known the harm brought by smoking.
D. To show people will someday notice the bad effects of sleep deprivation.

What does the underlined word "prioritize" in the last paragraph probably mean？ ______

A. Putting tasks in order of importance.
B. Getting more than enough of something to deposit it.
C. Treating something as being more important than others.
D. Cutting down something that is not necessary any more.

What can be the best title for the text？ ______

A. Weekend catch-up sleep is a lie
B. Bad sleep habits are harmful to health
C. Smoking is not the worst thing to health
D. A new study has an unexpected discovery