What is obesity? - Mia Nacamulli

翻译人员: 晓铮 张 校对人员: Ke Ding

The most basic function of bodily fat is self-storage of food reserves.

食物储备的自我存储是脂肪最基本的功能。

In prehistoric times, natural selection favored genotypes

在史前时期，以保存大量的脂肪 来忍耐恶劣坏境的基因型

that could endure harsh conditions by stocking the most fat.

在自然选择中胜出。

With chronic malnutrition being the norm for most of human history,

同时，因为慢性的营养不良普遍 存在于大多数的人类历史中，

genetics evolved to favor fat storage.

遗传基因朝着脂肪存储方向进化。

So when did body fat become problematic?

那么，身体脂肪什么时候开始成为了问题？

The negative impacts of being overweight were not even noted in medical literature

超重的消极影响直到18世纪才

until as late as the 18th century.

在医学记载中出现。

Then, technological advances coupled with public health measures

接着，科技进步与公共健康措施一起

resulted in the betterment of the quantity, quality, and variety of food.

提升了食物的产量、质量和丰富性。

Sustained abundance of good food enabled a healthier population

大量优质食物的持续供给使更健康的人口

to boom economically.

经济地增长。

Output increased, and with it, leisure time

随着产量的增加，人们的业余时间

and waistlines.

和腰围也随之增加。

By the mid 19th century, being excessively overweight, or obese,

到19世纪中期，极度超重或肥胖

was recognized as a cause of ill health,

被认为是不健康的，

and another century later, declared deadly.

而一个世纪以后，肥胖则被宣告是致命的。

What is the distinction between being overweight and being obese?

超重和肥胖之间的区别是什么？

A calculation called the BMI breaks it down for us.

BMI公式为我们解释了这个问题。

For example, if someone weighs 65 kilgorams

举例来说，如果一个人体重65千克

and is 1.5 meters tall,

身高1.5米，

they have a BMI of about 29.

其BMI值大约是29。

Obesity is a condition of excess body fat

肥胖意味着身体脂肪超标，

that occurs when a person's BMI is above 30,

即BMI超过30；

just over the overweight range of 25 to 29.9.

BMI在25-29.9之间则是刚刚超重。

While BMI can be a helpful estimate of healthy weight,

虽然BMI对估算健康的体重有一定帮助，

actual body fat percentage can only really be determined

但身体实际的脂肪百分比

by also considering information like waist circumference

只能由腰围和肌肉群

and muscle mass.

等信息决定。

Athletes, for instance, have a naturally higher BMI.

就像运动员天生就拥有较高的BMI。

So how does a person become obese?

那么，一个人如何肥胖起来的？

At its most basic, obesity is caused by energy imbalance.

从根本上来说，肥胖是由能量的不均衡导致的。

If the energy input from calories

如果来自卡路里的能量输入

is greater than the energy output from physical activity,

高于物理运动所输出的能量，

the body stores the extra calories as fat.

身体存储的多余卡路里就成了脂肪。

In most cases, this imbalance comes from a combination of circumstances

大多数情况下，这种不平衡来自环境

and choices.

和选择的结合。

Adults should be getting at least 2.5 hours of exercise each week,

成年人每个星期至少要拥有2.5小时的运动量，

and children a whole hour per day.

而儿童每天应有1个小时的运动时间。

But globally, one in four adults and eight out of ten adolescents

但是全世界有四分之一的成年人和五分之四的青少年

aren't active enough.

并不积极运动。

Calorie-dense processed foods and growing portion sizes

高热量的加工食品、不断增加的食物分量

coupled with pervasive marketing

和多样的食物市场共同

lead to passive overeating.

导致了消极的过度饮食。

And scarce resources,

而在贫困的社区，

and a lack of access to healthy, affordable foods

食物资源和得到健康又不太昂贵的食物的途径有限

creates an even greater risk in disadvantaged communities.

大大提升了出现问题的风险。

Yet, our genetic makeup also plays a part.

还有，我们基因组成也有一定作用。

Studies on families and on separated twins

对家庭和分开双胞胎的研究

have shown a clear causal hereditary relationship to weight gain.

已经发现了基因遗传和体重增长的关系。

Recent studies have also found a link between obesity

最近的研究也找到了肥胖

and variations in the bacteria species that live in our digestive systems.

和我们消化系统中细菌种类变化的联系。

No matter the cause, obesity is an escalating global epidemic.

无论何种原因，肥胖是一种逐步升级的全球性流行病。

It substantially raises the probability of diseases,

它更极大地提高了患上其他疾病的可能性，

like diabetes,

如糖尿病、

heart disease,

心脏病、

stroke,

中风

high blood pressure,

高血压

and cancer.

和癌症。

It affects virtually all ages, genders, and socioeconomic groups

它无形中影响了所有年龄，性别和社会阶层的人群，

in both developed and developing countries.

无论是在发达国家还是发展中国家。

With a 60% rise in child obesity globally over just two decades,

在刚过去的二十年中，全球儿童的肥胖率提高了60%，

the problem is too significant to ignore.

肥胖问题已经足够严重且难以忽视。

Once a person is obese, the climb to recovery becomes progressively steeper.

一旦肥胖起来，想要恢复就会非常的艰难。

Hormonal and metabolic changes reduce the body's response to overeating.

荷尔蒙的和新陈代谢的变化减少了身体对过度饮食的反应。

After losing weight, a formerly overweight person burns less calories

在减去体重以后，一个原先肥胖的人，

doing the same exercises

与原来就同样体重的人

as a person who is naturally the same weight,

做同样的运动，

making it much more difficult to shed the excess fat.

会燃烧更少的脂肪，这也就使减去多余的脂肪变得更加困难。

And as people gain weight,

当人们体重增加时，

damage to signaling pathways makes it increasingly difficult

大脑信号通路受到的伤害

for the brain to measure food intake and fat storage.

让大脑对食物摄入的测量和脂肪存储的判断难度上升。

There is, however, some evidence

但是，一些证据显示

that well-monitored, long-term changes in behavior

行为上良好的控制和长期的改变

can lead to improvements in obesity-related health issues.

能够帮助解决与肥胖相关的健康问题。

And weight loss from sustained lifestyle changes,

而且坚持减肥的生活方式

or invasive treatments like bariatric surgery,

或者如减重手术之类的治疗

can improve insulin resistance and decrease inflammation.

能够提高胰岛素抵抗力，并减少炎症的发生。

What was once an advantage for survival is now working against us.

一个曾经的生存优势正在与我们对抗。

As the world's population continues to slow down and get bigger,

随着世界的人口缓慢增长，

moving and consciously eating our way towards a healthier weight

拥有健康的体重，对于人类的幸福而言

is essential to our overall well-being.

非常重要，却也更加困难。

And with the epidemic affecting every country in the world

这种流行病正影响着全世界的每个国家。

for different socioeconomic reasons,

出于不同的社会经济原因，

obesity cannot be seen as an isolated issue.

肥胖不应该被当成一个孤立的问题。

More global measures for prevention

更多全球性的保护措施

are essential to manage the weight of the world.

对于管理世界人民的体重十分关键。