睡眠充足有利于保持好身材
[align=center][font=宋体][font=楷体_GB2312][size=4][color=red][b]不良的饮食习惯和缺乏锻炼肯定是全球范围内肥胖泛滥的重要原因。法国科学家发现，缺觉也可能是导致肥胖的原因之一，睡眠充足则有利于保持好身材[/b][/color][/size][/font][/font][/align][font=宋体][font=Times New Roman][size=3][color=black]An extra hour between the sheets at night might be the key to shedding excess weight and fighting obesity, according to recent research. [/color][/size][/font][font=Times New Roman][size=3][color=black]"More sleep could be the ideal way of stabilising weight or slimming," said neuro-scientist Karine Spiegel, of France's INSERM, a public organisation dedicated to biological, medical and public health research.[/color][/size][/font]
[font=Times New Roman][size=3][color=black]While poor eating habits and lack of exercise clearly play a role in the global rise of obesity, recent data indicates that lack of sleep may also be a factor, and one that is often under-estimated.[/color][/size][/font]
[font=Times New Roman][size=3][color=black]Around 30 surveys carried out on wide population samples in seven countries have underlined a link between lack of sleep and excess weight or obesity in both children and adults, Spiegel said.[/color][/size][/font]
[font=Times New Roman][size=3][color=black]The first of the studies, carried out in 1992 in France, highlighted the problem in children and teenagers. Spiegel said the increase in obesity in the US in the second half of the 20th century corresponded with a mounting decrease in sleep.[/color][/size][/font]
[font=Times New Roman][size=3][color=black]Two key hormones produced at night which help regulate appetite were at play, she said.[/color][/size][/font]
[font=Times New Roman][size=3][color=black]Grehlin makes people hungry, slows [b]metabolism[/b] and decreases the body's ability to burn body fat, and leptin, a protein hormone produced by fatty tissue, regulates fat storage.[/color][/size][/font]
[font=Times New Roman][size=3][color=black]"We have shown that less sleep (two four-hour nights) caused an 18 percent loss of appetite-cutting leptin and a 28 percent increase of appetite-causing grehlin," she said.[/color][/size][/font]
[font=Times New Roman][size=3][color=black]Such hormonal changes made people hungry for foods heavy in fats and sugars such as chips, biscuits, cakes and peanuts, she added.[/color][/size][/font]
[font=Times New Roman][size=3][color=black]The sleep loss caused a 23 to 24 percent increase in hunger, Spiegel said, translating into an extra 350 to 500 kilocalories a day, "which for a young sedentary adult of normal weight could lead to a major amount of added weight."[/color][/size][/font]
[font=Times New Roman][size=3][color=black]It was unclear whether several years of sleep deprivation could lastingly harm the body's ability to restore a balance between the two hormones.[/color][/size][/font]
[font=Times New Roman][size=3][color=black]A study released in Washington in February showed children lacking shut-eye faced a greater risk of becoming obese than kids who got a good night's sleep.[/color][/size][/font]
[font=Times New Roman][size=3][color=black]Each extra hour of sleep cuts a child's risk of becoming overweight or obese by nine percent, according to an analysis of epidemiological studies by researchers from Johns Hopkins Bloomberg School of Public Health.[/color][/size][/font]
[font=Times New Roman][size=3][color=black]By contrast, children who got the least sleep had a 92 percent higher chance of being overweight or obese than children who slept enough, said the study published in the journal Obesity.[/color][/size][/font]
[font=Times New Roman][size=3][color=black]"Our analysis of the data shows a clear association between sleep duration and the risk for overweight or obesity in children. The risk declined with more sleep," said Youfa Wang, a senior author of the study.[/color][/size][/font]
[font=Times New Roman][size=3][color=black]"Desirable sleep behavior may be an important low cost means for preventing childhood obesity and should be considered in future intervention studies," Wang said in a news release.[/color][/size][/font]
[font=Times New Roman][size=3][color=black]The researchers reviewed 17 published studies on sleep duration and childhood obesity.[/color][/size][/font]
[font=Times New Roman][size=3][color=black]Some research recommends that children under five years old sleep 11 hours or more a day, while children age five to 10 should get 10 or more hours of sleep, and children older than 10 should sleep at least nine hours.[/color][/size][/font]
[font=Times New Roman][size=3][color=black]（Agencies）[/color][/size][/font]
[font=Times New Roman][size=3][color=black]Vocabulary:[/color][/size][/font]
[b][font=Times New Roman][size=3][color=black]metabolism：[/color][/size][/font][/b][color=black]新陈代谢[/color]
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