Your healthcare news library

Posts tagged ‘BMI’

People can be fat yet fit, research suggests

By Michelle Roberts Health editor, BBC News online

Obese man at the gym
Some obese people were as ‘metabolically fit’ as people of ideal weight

People can be obese yet physically healthy and fit and at no greater risk of heart disease or cancer than normal weight people, say researchers.

The key is being “metabolically fit”, meaning no high blood pressure, cholesterol or raised blood sugar, and exercising, according to experts.

Looking at data from over 43,000 US people they found that being overweight per se did not pose a big health risk.

The results are published in the European Heart Journal.

In the study at the University of South Carolina, more than a third of the participants were obese.

Of these 18,500, half were assessed as metabolically healthy after a physical examination and lab tests.

This subset of metabolically healthy obese people who did not suffer from conditions such as diabetes, high cholesterol or high blood pressure, were generally fitter and exercised more than the other obese people.

And their risk of developing or dying from cardiovascular disease or cancer was identical to people of ideal weight and was half that of “metabolically less fit” obese people.

These studies remind us that it is not always your weight that’s important, but where you carry fat and also how it affects your health and fitness”

Amy Thompson British Heart Foundation

Lead researcher Dr Francisco Ortega, who currently works at the University of Granada in Spain, said the findings show that getting more exercise can keep you healthier, even if you still carry a bit of extra weight.

“This research highlights once again the important role of physical fitness as a health marker.”

Most of the men and women in the study came from a similar background, meaning the results may not apply to everyone. They were mostly Caucasian, well educated, and worked in executive or professional positions.

Amy Thompson, of the British Heart Foundation, said: “In the majority of cases, obesity is an undeniable risk factor for developing coronary heart disease. However, these studies remind us that it is not always your weight that’s important, but where you carry fat and also how it affects your health and fitness.

“It is particularly important to be aware of your weight if you are carrying excess fat around your middle. The fat cells here are really active, producing toxic substances that cause damage which can lead to heart disease.

“Maintaining a healthy diet with lots of physical activity can help to slim you down as well as reduce your risk of heart health problems.

“But don’t get too caught up on the numbers on the scale. Calculating your body mass index and measuring your waist are great ways to keep on track. If you are concerned about your weight and want to make changes to your lifestyle, make an appointment with your GP to talk it through.”

BBC

新的肥胖指数工具 能更好地预测早死风险

美国大约三分之二的成年人属于超重,其中约三分之一的人肥胖。许多专家认为,目前用来确定肥胖的标准测量方法——体重指数(BMI)存在一定的缺陷,因为它不能区分脂肪和肌肉,导致判断错误。来自纽约市立大学的研究人员开发出一种确定肥胖的新测量工具,该工具能预测一个人过早死亡的风险。

Krakauer说,“我们能够证明,那些被测量ABSI数据高的人,在五年内死亡率也高。”(照片:路透社/Finbarr O’Reilly )举个例子来说,一个身高183CM,选择健康饮食并经常健身的男人,体重可能与整天躺在沙发上看电视吃零食的胖邻居一样重,但通过BMI换算出来的结果表明经常健身的男人也超重,因为它不能分辨肌肉和脂肪。

Nir Krakauer教授和他的同事Jesse Krakauer纠正了这一缺陷。他们在BMI中添加了另一指标,即身体形态,将腰围尺寸也作为衡量肥胖的一个指标,腰围尺寸越大肥胖程度越高。

研究人员将新的测量方法命名为身体形态指标(ABSI)。

研究人员说,随着ABSI的增加,死于肥胖的风险也增加。

Krakauer说,“我们能够证明,那些被测量ABSI数据高的人,在五年内死亡率也高。”

在这项研究中,研究人员分析了超过1万4千人的医疗记录。他们发现ABSI数据高(肥胖)的人早死风险比正常人高出两倍。

虽然,新的测量系统能够预测各种人群(性别,年龄和种族)的早死风险,但唯有墨西哥血统的人无法被预测。

作为一名土木工程师,Krakauer的兴趣是,气候的变化和人类活动如何影响地球水循环和碳循环?为了找到答案他转向研究医疗数据,因为分析这两个领域包含了从巨大的数据集中提取模式。这些模式有助于测试该预测系统能否有效。

“很长一段时间我爸爸一直在做与身体组成有关的工作,但总是缺乏一些证据证明(身体组成)对风险量化的作用。我的经验是,通过寻找大型数据集来帮助评估该预测系统的可行性和准确性。”

研究结果发表在《PLOS ONE》上。

医药日报发布

從BMI與體脂看身材 健康才是美

◎ 記者杜宇喬/綜合報導

(優活健康網記者杜宇喬/綜合報導)現代的女性相信「瘦即是美」,明明身體質量指數(Body Mass Index, BMI)在正常範圍內,仍不斷減輕體重,這種盲目的減肥風氣,讓許多女性不惜賠上健康也要變身「紙片人」!判斷自己是否夠「苗條」,每個人主觀認知的部分差異頗大;若因瘦身造成營養不良,長期下來對健康造成很大的傷害,除了以 BMI 值之外,測量「體脂肪」也能精準判斷出是否過胖。

營 養不良將導致身體削瘦,各方面的抵抗力都會減弱;而若是在短時間內快速減輕10%以上的原始體重,更是健康的大敵,因為此時所減去的體重大部分會是體內重 要的瘦肉組織!在醫院中,若有患者體重如此下降,會被列為營養不良的高風險群,必須予以積極的營養治療與支持,否則死亡率是很高的。

男性標準腰圍≦90公分;女性≦80公分。健康成年女性體內所含的總脂肪量約為21~35%,男性則為10~20%,其中「必須脂肪」小量的散佈於骨髓、心、肺、肝、脾、腎、肌肉、神經組織及女性特有的乳房、骨盆腔及大腿等部位中,是正常生理作用所需要的;其餘則是「貯存性脂肪」,主要堆積於皮膚層下及內臟周遭,保護臟器不易受到撞擊、創傷,所以體脂肪不是越少越好。

uho優活健康網

Chocolate ‘may help keep people slim’


Chocolate contains antioxidants but is also high in fat and sugar

By Michelle Roberts Health reporter, BBC News

 

People who eat chocolate regularly tend to be thinner, new research suggests.

The findings come from a study of nearly 1,000 US people that looked at diet, calorie intake and body mass index (BMI) – a measure of obesity.

It found those who ate chocolate a few times a week were, on average, slimmer than those who ate it occasionally.

Even though chocolate is loaded with calories, it contains ingredients that may favour weight loss rather than fat synthesis, scientists believe.

Despite boosting calorie intake, regular chocolate consumption was related to lower BMI in the study, which is published in Archives of Internal Medicine.

The link remained even when other factors, like how much exercise individuals did, were taken into account.

And it appears it is how often you eat chocolate that is important, rather than how much of it you eat. The study found no link with quantity consumed.

According to the researchers, there is only one chance in a hundred that their findings could be explained by chance alone.

But the findings only suggest a link – not proof that one factor causes the other.

Lead author Dr Beatrice Golomb, from the University of California at San Diego, said: “Our findings appear to add to a body of information suggesting that the composition of calories, not just the number of them, matters for determining their ultimate impact on weight.”

This is not the first time scientists have suggested that chocolate may be healthy for us.

Other studies have claimed chocolate may be good for the heart.

Consumption of certain types of chocolate has been linked to some favourable changes in blood pressure, insulin sensitivity and cholesterol level.

And chocolate, particularly dark chocolate, does contain antioxidants which can help to mop up harmful free radicals – unstable chemicals that can damage our cells.

Dr Golomb and her team believe that antioxidant compounds, called catechins, can improve lean muscle mass and reduce weight – at least studies in rodents would suggest this might be so.

Mice fed for 15 days with epicatechin (present in dark chocolate) had improved exercise performance and observable changes to their muscle composition.

They say clinical trials are now needed in humans to see if this is the case.

But before you reach for a chocolate bar, there are still lots of unanswered questions. And in the absence of conclusive evidence, experts advise caution.

While there’s no harm in allowing yourself a treat like chocolate now and again, eating too much might be harmful because it often contains a lot of sugar and fat too.

And if you are looking to change your diet, you are likely to benefit most from eating more fresh fruits and vegetables.

Read More: BBC

A Daily Walk Can Reduce the Power of Weight-Gaining Genes


Jacom Stephens / Getty Images

Body weight, like so many of our individual characteristics, is the combined result of the genes we’re born with and the way we live our lives — how much and what we eat, and whether we exercise. The question is, how much does one influence the other?

In a new study, reported at the American Heart Association’s annual meeting on Epidemiology and Prevention/Nutrition, Physical Activity and Metabolism in San Diego, researchers offer evidence that lifestyle can actually change the effect our genes have on the number on the scale.

Qibin Qi of the Harvard School of Public Health and his colleagues say that walking for about an hour a day can reduce the weight-promoting effect of certain genes by 50%. What’s more, the scientists say, sedentary activities like watching TV can trigger the weight-gaining effect of the same genes.

VIDEO: A Faster Stride Predicts a Longer Life

The study involved more than 12,000 men and women enrolled in the long-running Nurses’ Health Study and Health Professionals Follow-Up Study, which track lifestyle behaviors and health outcomes among doctors and nurses and other health care professionals. In order to determine how much influence the weight-gaining genes had on the participants’ weight, Qi and his colleagues focused on 32 genes that have previously been linked to body mass index (BMI), a ratio of height and weight that is used to determine overweight and obesity.

The researchers plotted the participants’ BMI against their so-called weight-gene score, a measure of how many variants of the 32 genes they possessed. Because we obtain one copy each of every gene from our mother and father, the maximum number of weight-promoting variants a subject could have was 64, and the minimum was zero. It turned out that no one was burdened with two copies of every BMI-increasing gene; the maximum number of variants in the study subjects totaled 43, while the minimum number of variants was 10. Based on this comparison, the researchers determined that for every genetic variant, the effect on BMI was to increase it by 0.13 kg/m2.

But among those who walked briskly for about an hour a day, this genetic effect was reduced by 50%, to 0.06 kg/m2. It’s the first study to bring the effect of exercise down to the genetic level, and to measure how physical activity can change the way genes work — in this case by inhibiting the activity of genes that promote weight gain.

 

The study also documented an increase in the activity of these genes among those who were more sedentary. For every two hours spent in front of the television every day, there was a 0.3 kg/m2 increase in BMI.

The fact that walking and TV watching each had independent effects on BMI hints that it’s important both to increase exercise and reduce sedentary time in order to lose weight. In other words, it’s not enough to be physically active most of the day if you’re still sitting on the couch watching TV for several hours. “We suggest that both increasing physical activity and reducing sedentary behavior can lower the genetic predisposition to obesity,” says Qi.

The authors acknowledge that it may not be the act of TV watching itself that enhances the activity of the weight-promoting genes. It may be that people who watch more TV also tend to eat more and exercise less, for example. But the latest findings provide some hope that even if you’re not blessed with lean genes — and not many of us are — you can modify the fattening effect of your DNA by changing how you live your life.

Read More: Time

Tag Cloud