研究表明，普通人可能比大象还要胖

研究表明，普通人可能比大象还要胖

Elephants may be the largest land mammals on the planet, but new research reveals that the typical human is in fact flabbier than these colossal creatures. Appearing in the Journal of Experimental Biology, the new study sheds light on the health of captive Asian elephants, suggesting that their low reproductive rates may not be due to an excess of body fat.

大象可能是地球上最大的陆地哺乳动物，但新的研究表明，典型的人类实际上比这些巨型动物更松弛。这项发表在《实验生物学杂志》上的新研究揭示了圈养亚洲象的健康状况，表明它们的低繁殖率可能不是由于身体脂肪过多。

Sadly, many captive populations of Asian elephants are not self-sustaining, leading to concern among biologists that obesity may be affecting the animals’ fertility. However, while it’s true that captive elephants generally tend to carry more body fat than their wild counterparts, the impact of this extra weight on the animals’ health has never been properly investigated.

遗憾的是，许多圈养的亚洲象种群无法自我维持，导致生物学家担心肥胖可能会影响这种动物的生育能力。然而，虽然圈养大象通常比野生大象携带更多的脂肪是事实，但这种额外的体重对动物健康的影响从未得到过适当的调查。

A team of researchers, therefore, set out to measure exactly how much body fat captive Asian elephants carry relative to their body weight, in order to discern if they can really be labelled obese. Explaining the difficulty in making such a determination, study author Daniella Chusy said in a statement that “obesity is not clearly defined in humans, let alone elephants.”

因此，一组研究人员开始测量圈养亚洲象体内的脂肪与体重的比例，以确定它们是否真的可以被贴上肥胖的标签。该研究的作者丹妮拉·楚希在一份声明中解释了做出这一决定的困难，她说:“人类肥胖的定义并不明确，更不用说大象了。”

Benjamin Taub

In their write-up, the authors expand on this issue by explaining that “obesity is a social creation to describe people with high levels of adiposity, and was originally developed based on mortality data.” However, applying such a diagnosis to elephants is fraught with difficulty as “there are no data on the relationship between adiposity levels and mortality in elephants.”

在他们的文章中，作者进一步解释道:“肥胖是一种社会创造，用来描述高度肥胖的人，它最初是基于死亡率数据而产生的。”然而，将这种诊断应用到大象身上困难重重，因为“没有关于大象肥胖水平和死亡率之间关系的数据。”

A total of 44 Asian from zoos across the US and Canada were included in the study, 35 of which were female while the remaining nine were male. To measure the animals’ body fat, the researchers fed them slices of bread that had been soaked in heavy water, which contains an isotope of hydrogen called deuterium.

来自美国和加拿大动物园的44名亚洲人参与了这项研究，其中35名是女性，其余9名是男性。为了测量这些动物的身体脂肪，研究人员让它们吃在重水中浸泡过的面包片，重水中含有一种叫做氘的氢同位素。

Zookeepers collected blood samples from the elephants in order to allow the researchers to measure the levels of deuterium circulating in each animal’s serum. By subtracting the amount of water in an elephant’s blood from its total body weight, the team was able to determine each individual’s fat level.

动物园管理员收集了大象的血液样本，以便研究人员测量每只大象血清中循环的氘水平。通过从大象的总体重中减去血液中的水分，研究小组能够确定每个大象的脂肪水平。

On average, male elephants were found to carry about 8.5 percent body fat while females carried around ten percent. By contrast, the average healthy person has a fat content of between six and 31 percent, meaning most of us have a higher ratio of fat to body weight than a captive Asian elephant.

平均而言，公象体内脂肪含量约为8.5%，母象体内脂肪含量约为10%。相比之下，正常人的平均脂肪含量在6%到31%之间，这意味着我们大多数人的脂肪与体重的比例比圈养的亚洲象还要高。

More importantly, results also revealed that the least fertile female elephants tended to be those with the lowest fat levels, suggesting that low reproductive rates are not caused by obesity. Rather, it seems that being underweight carries the greatest risk of infertility among female captive Asian elephants.

更重要的是，研究结果还揭示，最不具生育能力的母象往往是那些脂肪含量最低的，这表明低繁殖率不是由肥胖造成的。更确切地说，在雌性圈养亚洲象中，体重过轻是导致不孕的最大风险。

Furthermore, observations revealed that the elephants in the study tended to walk between 0.03 and 2.8 kilometers an hour. Previous research has found that wild Asian elephants generally walk between 0.01 and 1.15 kilometers per hour, indicating that the extra weight carried by captive elephants is not due to inactivity.

此外，观察显示，研究中的大象往往以每小时0.03到2.8公里的速度行走。此前的研究发现，野生亚洲象的行走速度一般在每小时0.01到1.15公里之间，这表明圈养大象携带的额外重量并非由于不活动。

Finally, the researchers report that insulin levels tended to be higher among the fattest elephants, raising concerns that some may run the risk of developing diabetes-like symptoms. Overall, the study authors tentatively suggest that elephants with a fat content of more than 14 percent could be considered obese, as this threshold was associated with elevated levels of blood insulin.

最后，研究人员报告说，最胖的大象体内的胰岛素水平往往更高，这引起了人们的担忧，有些大象可能会出现类似糖尿病的症状。总的来说，研究作者尝试性地提出，大象的脂肪含量超过14%可以被认为是肥胖，因为这个阈值与血液胰岛素水平升高有关。

The researchers are keen to point, however, that more research is needed in order to verify this preliminary conclusion. Overall, though, they are pleased to report that on the whole, captive Asian elephants do not appear to be obese.

然而，研究人员热衷于指出，需要更多的研究来验证这一初步结论。不过，总的来说，他们很高兴地报告说：圈养的亚洲象似乎并不肥胖。