Researchers say a "Venus" figurine discovered in 2008 in southern Germany and created an estimated 35,000 years ago may be the oldest statue ever found. Its sexually suggestive figure— large breasts, large rear end—is said to connote fertility. But it also looks extremely fat. Were there obese people in prehistoric times?

    Few, if any. Obesity is defined as having a body mass index higher than 30—the equivalent of being about 5-foot-11 and 220 pounds. The best indicator of body type among prehistoric peoples is present-day societies with a similar lifestyle—that is, hunter-gatherers. From the San people of Botswana to the PygmiesBatek of Malaysia, groups that fall into this category tend to be small and extremely thin. The Baka of Cameroon, for example, are about 5 feet tall and weigh around 105 pounds, giving them an average BMI of 20. Hunter-gatherers are usually thin because they subsist largely on fruits and vegetables, underground tubers, and, in some regions of Africa, honey. They also get calories from animal meat, and some of their diets are especially fish-heavy. But many tribes insist on distributing the meat evenly among the group, so there's rarely enough for one person to get fat on. Hunter-gatherer tribes also stay thin, unsurprisingly, due to a generally active way of life.

    Fossils are of little use in determining the relative fitness of Stone Age humans because, for the most part, the bones of a 150-pound man look similar to the bones of a 250-pound man of the same height. Many old bones do have stress fractures or signs of arthritis, but it's hard to conclude that these indications of degradation are due to obesity. Neanderthals 200,000 years ago were shorter and stockier than we are now, but, again, there's no evidence that they were obese.

    Obesity likely began with the advent of agriculture 12,000 years ago. Food surpluses and the relatively sedentary lifestyle on settlements made overconsumption possible for the first time in human history. Another factor was the rise of processed foods and, with the invention of the steel roller mill in the late 19th century, the possibility of mass-marketing those foods. Grains and other carbohydrates that have been broken down are easier to digest. As a result, you get hungry again faster. Some scientists also theorize that people weighed less in earlier eras because they were exposed to more infections. (If you're eating carrots out of the ground—as opposed to a sealed plastic bag—you're likely to have constant minor parasitic infections.) When you're fighting an infection, your body temperature rises, and you burn more calories.

    Some women in hunter-gathering societies do have abnormally large buttocks, a condition called steatopygia. It's especially common among the Khoisan in southern Africa and tribes in the Andaman Islands. It is sometimes considered a sign of beauty, and may have inspired some of the more voluptuous ancient figurines. The most famous example of steatopygia was the Hottentot Venus, a Khoikhoi woman whose physical characteristics made her a sideshow sensation in 19th-century Europe.

    2008年，在德國南部發(fā)現(xiàn)了一尊“維納斯"的雕像。這尊雕塑如果確實(shí)如研究者聲稱雕刻于35,000年前，那么她將是世界上已發(fā)掘的最早的雕像。豐滿的乳房、碩大的臀部，這些突出的性征據(jù)說是生育力強(qiáng)的象征。但是，她看起來也確實(shí)很肥。那么，在史前時期，是否存在肥胖的人？

    即使有，也是極少數(shù)的。肥胖指的是體重指數(shù)高于30的，比如說，170cm的人卻有220磅（相當(dāng)于99.7903KG）。史前人類身體的各項(xiàng)指數(shù)與現(xiàn)在社會中的采獵者（hunter-gaterers）這類人的指數(shù)相近。這一類型的人，不論是圣博茨瓦那人（San people of Botswana），還是馬來西來的俾格米人（Pygmies Batek），他們都很矮小并且非常地精瘦。又比如，身高152.4cm、體重47.7kg的咔麥隆的巴卡（The Baka of Cameroon）人，他們體重的平均指數(shù)只有20。采集者之所以比較瘦是因?yàn)樗麄兇蠖嗫克�果、蔬菜、地下塊莖狀植物維持生命，非洲一些地區(qū)也會采食蜂蜜。他們也會吃動物的肉來獲取能量，有些人更是以魚為主食。但更多的部落仍堅持肉要均分，因此每一個人得到的肉的份量很難讓他胖起來。另外，采獵部落的人一直長不胖的另一個可想而知的原因即是他們總是為了生存忙個不停。

    我們無法依靠化石來斷定石器時代人類的身體比例。因?yàn)樵诖蠖鄶?shù)情況下，如果身高相同，一個150磅（約68Kg）的人和骨架和一個250磅（約 113.4Kg）看起來差不多。雖然很多原始人的骨骼被檢測出有骨折或者是關(guān)節(jié)炎的癥狀，但這些退化的跡象并不能得出它們是肥胖所致的這一結(jié)論。同樣，雖然200,000萬年前的尼安德特人（Neanderthals）比我們要矮小但卻更健壯結(jié)實(shí)，我們?nèi)詻]有證據(jù)證明他們會患肥胖癥。

    肥胖癥可能是隨著12,000年前農(nóng)業(yè)社會的到來而出現(xiàn)的。食物的富余和相對穩(wěn)定不變的定居生活，這為人類歷史上第一次過度消費(fèi)提供了可能性。另一個原因是加工食品的增多，并且，由于19世紀(jì)末鋼滾輪面粉廠的出現(xiàn)，為這類加工食品的大批量生產(chǎn)提供了條件。谷物以及其它的碳水化合物都被磨碎，從而更容易被消化。于是，你也變得更容易餓了。一些科學(xué)家還猜測，早期的人類體重更輕可能也跟他們身處更多的感染疾病的環(huán)境有關(guān)。（如果你吃的胡蘿卜是剛從土里挖出來，而不是保存在一個密封的塑料袋里，那么你便很可能會一直受到微小寄生蟲的感染。）當(dāng)你和這些傳染病抗?fàn)帟r，你的體溫就會升高，從而消耗掉更多的熱量。

    采獵社會里，有些女人的臀部確實(shí)可能大得有些不正常，現(xiàn)在稱之為臀脂過多（steatopygia）。這在南非的科伊桑人和安達(dá)曼群島的部落中尤為常見。某些時候，這樣的身材被視為美麗的象征，并且由此產(chǎn)生了這些更具感官刺激的古代雕像。臀脂過多的著名例子就是霍屯都的維納斯（Hottentot Venus），這個科伊科伊女人，以她的肉體特征成為了19世紀(jì)歐洲的雜耍界的“風(fēng)云"人物。