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
2019-04-30
61
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.
There are 600 million people who are obese in the world and the proportion is still growing.
选项
答案
B
解析
转载请注明原文地址:https://kaotiyun.com/show/LGX7777K
0
大学英语六级
相关试题推荐
Adultsaregettingsmarteraboutbowsmartbabiesare.Notlongago,researcherslearnedthat4-day-oldscouldunderstand【B1】__
ThePublicHealthCrisisHidinginOurFood[A]Ifyouhavehighbloodpressure,you’reingoodcompany.Hypertension(高血压)affl
A、Itallowsthemtomeetstudentsfromotheruniversities.B、Itpromotestheconceptofself-learning.C、Itallowsmoreflexibil
Weallhopethatthevaluesthatareimportanttoeachofusarepassedalongtoourchildren.Often,however,thathopeischal
打车难已经成为大城市人们生活中较为普遍的问题。城市人口规模的扩大以及人类社会活动的不断多元化(diversification)都增加了对出租车的需求。随着城市交通拥堵状况不断加剧,为避免堵车影响收入,上下班高峰时段很多司机不愿意跑拥堵路段和主城区。这导致市
Directions:Forthispart,youareallowed30minutestowriteanessaycommentingonhowpeopleshouldreactwhenfacingthead
元宵(riceglueball)是一种中国人在农历正月十五元宵节烹制食用的食品。元宵节吃元宵的习俗可追溯到宋代。元宵用糯米粉(glutinousriceflour)等原料做成,呈圆形,又叫“汤圆”“汤团”,这些名称都与“团圆”发音相近,所以元宵象征
Itwasgoingtohaveroughlytheeffectofaneutronbombattackonhighstreetsandshoppingmalls.Thebuildingswouldbeleft
A、Ithasbeenfinished.B、Itwillbepublishedthismonth.C、Itcontainsmanydetectivestories.D、Itranksthetopofbestselle
Aristotledefinedafriendas"asinglesouldwellingintwobodies".Howmanyfriendswehave,andhoweasilywemake,maintain
随机试题
社会保障制度是市场经济运行的“减震器”和“安全网”。
下列调整幻灯片位置的说法正确的是________。
A、questionB、notionC、exceptionD、vocationA
以下哪项不是食品加工、贮存中产生的有害物质
属于真核细胞型的微生物是
松园公司与天利公司协商劳务派遣协议的下列条款中,不符合法律规定的有:
某居民小区位于市郊区外环线边缘,小区内有住户1840户,常住居民5300多人,基本上都是二十世纪五六十年代支边支农回城的人员、动迁人员和外地入住人员。小区人员有三大特点:一是无业和生活困难的居民多;二是六十岁以上的老人多;三是外来人员多。小区所在社区接上级
吴某深夜潜入陈某家中盗窃,发现房间内有一十分名贵皮箱(内有现金10万元),怕拖动时惊动陈某,便扔到墙外。偶尔经过的孙某发现皮箱无人看管,便将其拿走据为已有。吴某环顾房内其他地方没有发现值钱东西后,来到院墙外,发现皮箱已不见踪影。对吴某和孙某行为的定性,下列
曲面上任何点处的切平面在各坐标轴上的截距之和为__________。
在段定义伪指令语句中,下列哪一种组合类型是不可缺省的?
最新回复
(
0
)