首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
Your weight affects how long you live—but it’s extremely complicated A) We often think about weight loss in the short term, h
Your weight affects how long you live—but it’s extremely complicated A) We often think about weight loss in the short term, h
admin
2020-09-03
27
问题
Your weight affects how long you live—but it’s extremely complicated
A) We often think about weight loss in the short term, hoping to drop 5 pounds in time for vacation or 10 in time for a wedding. Of course, this kind of yo-yo dieting isn’t the greatest for our health. If you’re going to ask how much you should weigh, you want to think long term—what weight will keep you healthy?
B) This question has been at the forefront of researchers’ minds for a while, and for good reason. Global obesity rates are high and steadily increasing, with 1.3 billion adults considered overweight and 600 million in the weight range categorized as obese.
C) While it’s true that muscle weighs more than fat, most people who are carrying around a few extra pounds are doing so in the form of adipose (脂肪的) tissue. Unlike bone and muscle, fat cells can generate inflammation (炎症), allowing us to heal infections and protect our bodies from further damage. But having too many fat cells causes our bodies to release inflammatory proteins all the time. Many studies indicate this can increase our risk of developing cancer.
D) Carrying around extra fat cells also affects other physiological pathways, many of which—high blood pressure, hyperglycemia (高血糖症) , and high cholesterol, for example—can lead to potentially fatal heart problems.
E) We all need some amount of body fat. So how much is too much? Using BMI (body mass index, the body mass divided by the square of the body height) and rates of overall mortality, scientists studying this question initially came to a surprising conclusion: On a population level, the relationship between BMI and mortality formed a U-shaped curve, in which the lowest point (the one where mortality was at its lowest) was actually at a BMI range considered nearly overweight (about 24.5, when 25 is overweight). Bring on all the healthy fats and carbs (含碳水化合物的食物).
F) But some scientists—including Andrew Stokes, a chronic disease and global health researcher at Boston University—challenged those conclusions. Instead of a U-shaped curve, his group’s follow-up studies saw the risk of mortality increase with higher BMIs. The lowest risk category, he says, is somewhere in the low-normal weight range, and risk increases pretty consistently as BMI goes up.
G) The earlier studies failed to account for two important factors, according to Stokes. "The normal weight category used in most of the studies combines low-risk, stable weight people with high-risk individuals who have lost weight," he says. If a study subject spends most of his life obese and then loses weight, he might accumulate years of negative health effects. Not all of those risks disappear with weight loss. "Much of the research on obesity just uses a snapshot (简要描述) of weight currently," says Stokes.
H) Stokes equates this to the way we study smoking. You can’t simply compare non-smokers to smokers. Non-smokers include those who have never smoked as well as those who may have smoked for several decades and then quit.
I) And smoking itself is another crucial factor in these BMI studies, Stokes says. Smoking can present a huge bias in estimating risks associated with obesity, because the habit affects body weight through metabolic effects and reduced appetite. By failing to take smoking into account, your analysis may include people who have a low body weight but smoke heavily, upping their chance of an early death. Once those outliers are removed, Stokes and his colleagues argue, the relationship between excess body weight and early mortality is clear.
J) Of course, the range for normal BMI is pretty broad. For example, someone who is 5’4" has a normal BMI if they weigh anywhere from 108 pounds to 145 pounds. If we want to know which sliver of the range is actually best, Stokes says, researchers have a lot more work to do.
K) And then there’s the question of whether BMI is the right metric to use at all. BMI is often criticized as a poor indicator of health. Because muscle weighs more than fat, a weightlifter could have a BMI in the overweight range, and that’s to say nothing of all the other variations the human form can take. Even two folks with the same BMI and the same amount of actual body fat might face different risks due to their adipose, if one carries more in their belly and the other stores more in their hips. Studies that compare BMI to superior methods like the Dexa scan, a type of X-ray that can determine exactly how much body fat you have and where, show that the potential misclassification is not trivial. But Stokes argues that on a population level, BMI is a pretty good parameter to use. Variations in its accuracy do exist, but it’s not so wildly off-base as to be useless when we make generalizations about risks throughout an entire population.
L) But that’s the key here: We’re talking about average risk. None of this is to say that someone with an ideal BMI is bound to outlive someone who is obese. There are plenty of other factors at play in determining our health, including genetics, exercise, diet, and especially stress. The degree of fat we carry often intertwines with these other characteristics, but it’s still only one factor. An individual’s health can’t be determined by a number on a scale, and one should always talk to a doctor when considering major lifestyle changes.
M) Still, while there’s no scientific consensus on what range of normal BMI equates to lowest overall mortality, Stokes hazards a guess for the lower end, perhaps 20 to 22. He also points out that many studies (on rodents and primates, anyway) show calorie restriction can increase longevity. One population he thinks we should study more are those humans who have always had a very low BMI. Ping-ponging your weight around to try to get on the lowest possible end of the healthy threshold is definitely not a good idea, but living your entire life with a BMI on the lower end—maybe even under 20—could decrease risk of diseases like cancer and diabetes. It’s an important question, Stokes says, and one that not enough researchers are asking.
If a person is overweight for long, even though his weight drops later, he may still have potential health problems.
选项
答案
G
解析
转载请注明原文地址:https://kaotiyun.com/show/gXP7777K
0
大学英语六级
相关试题推荐
A、Bycontrollingthecarriersofthedisease.B、Bygrowingastrongerkindoftheelm.C、Bywateringinfectedelmtrees.D、Bycu
Sugar—FriendVSEnemyA)Sugariseverywhere.It’sinourdrinks,it’sinourfoods,andit’shiddeninplacesweneverwouldth
Forthispart,youareallowed30minutestowriteashortessayonlivinginthevirtualworld.Trytoimaginewhatwillhappen
A、Sentastorytothelocalnewspaper.B、ThrewasmallThanksgivingparty.C、Bakedsomecookiesasapresent.D、Wroteapersonal
A、Allserviceswillbepersonalized.B、Alotofknowledge-intensivejobswillbereplaced.C、Technologywillrevolutionizealls
A、Puttingtimeandeffortintofunthingsisprofitable.B、Peoplewholovewhattheydocarelittleaboutmoney.C、Beingpassion
A、Itwascreatedmainlyforscientificresearch.B、Itworksbetterinfineweatherconditions.C、Itmustbelocatedonatleast
HowPovertyChangestheBrainA)Yousawthepicturesinscienceclass—aprofileviewofthehumanbrain,sectionedbyfuncti
民宿(minshuku)指的是为游客提供食宿的家庭经营的旅馆或私人住宅。20世纪60年代初期,在英国西南部与中部,人口较稀疏(sparse)的农家为了增加收入开始经营民宿。随着民宿业在日本的快速发展,中国南方地区也出现了许多民宿。居住在民宿的旅客可以享受基
北京观光客自然都会游览故宫和长城,这是因为故宫和长城是举世闻名的旅游景点。然而,对于北京第三大旅游场所——北京世界公园,人们却知之甚少。北京世界公园于20世纪90年代初竣工,占地面积46.7公顷,分为17处风景区,收集了各个洲的主要名胜景点。北京世界公园的
随机试题
患者,女,68岁。因乳腺癌住院化疗。为其输液过程中,患者出现呼吸困难,听诊心前区有响亮的水泡音,患者可能发生空气栓塞。空气栓塞的部位是在
胃十二指肠溃疡急性大出血,失血量在______以上时,病人出现循环系统代偿表现,失血达到______以上时,病人有明显的休克表现。
There_______noonetohelpmeatthismoment,Ineedtohandletheworkallbymyself.
与传统CT比较,滑环技术改进的核心是
下列关于证券承销的说法中,错误的是哪项?
()对基金实施行业自律管理。
在特殊的普通合伙企业中,一个合伙人或数个合伙人在执业活动中,非因故意或重大过失造成合伙企业债务的,应当承担无限责任或无限连带责任,其他合伙人以其在合伙企业中的财产份额为限承担责任。()
某企业集团的下列业务单位中,适合选择成本领先战略的有()。
民族区域自治制度是我国解决民族问题的基本政策,是我国基本政治制度之一,民族区域自治制度的核心是
Inthissection,youwillhearashortpassage.Forquestions21-30,completethenotesusingnomorethanthreewordsforeach
最新回复
(
0
)