This is Scientific American — 60-Second Science. I'm Steve Mirsky.
"We focus on what is called recurrent obesity or yo-yo obesity, which is a feature which affects close to 80 percent of all overweight individuals worldwide."
Eran Elinav of the Weitzmann Institute of Science in Israel.
"This is the phenomenon in which we gain weight and then we go on a successful diet, but within 12 months we go back to our original weight. And we even gain more weight from cycle to cycle. So this is called recurrent obesity."
But Elinav may have taken a step toward getting a handle on that frustrating post-diet pound packing that leaves people heavier than when they started. He spoke February 17th at the annual meeting of the American Association for the Advancement of Science in Boston.
"We developed a few models in mice, which feature this exact pattern of recurrent exaggerated obesity...following cycles of obesity and successful dieting. And what we found was that the one important determinant which drives this exaggerated weight regain tendency is a persistent alteration of the composition and function of our gut microbiome following a successful dieting. In other words, we diet and we normalize all of our metabolic parameters after we successfully diet..."
But we still can maintain the microbial profile—and function—that we had before losing the weight. So Elinav's team did a detailed analysis of the biochemistry going on within the mice.
"And we came across two molecules in mice which are from the flavonoid family. And basically these molecules signal to the host adipose tissue telling it to extract more heat and to gain less fat."
The molecules, called apigenin and naringenin, get degraded in the presence of the obesity-related microbiome.
"And when they are low the fat doesn't get this signal and then weight regain occurs. So in this particular case the intervention which we've used is to replenish these two missing or these two degraded molecules through administration in food and their drinking water. And when we brought them back to physiological levels we completely abolished this tendency for an exaggerated weight regain."
"Now extrapolating to humans, if this is true in humans and we would discover these or maybe other molecules which are depleted or in excess...an intervention which would supplement them or block their downstream signaling would potentially be helpful in this regard."
For listening for Scientific American — 60-Second Science Science. I'm Steve Mirsky.
“这是一种现象，一个人在体重增加后通过节食成功减重，但是在12个月以内又恢复到原有的体重 。在一轮又一轮的增重和减肥以后，人们的体重甚至会比原来更重 。因为这种现象被称为复发性肥胖 。”
减肥之后的反弹令人们沮丧，而且会使人们的体重比之前更重，不过伊利那夫可能已经开始采取措施解决这种问题了 。他在2月17日于美国波士顿举行的美国科学促进协会上发表了讲话 。
“我们用小白鼠研发了几个模型，这些模型的特征是，在周期性的肥胖和成功节食以后，体重不断反弹并且增加 。我们发现，导致这种体重反弹倾向的重要决定性因素是，成功节食以后我们肠道微生物的组合和功能在不断变化 。换而言之，在成功节食减肥后，我们正常进食会将所有新陈代谢参数正常化 。”
但是，我们仍能将微生物的状态和功能维持在减肥前的水平 。所以，伊利那夫的团队对小白鼠体内发生的生物化学过程进行了详细分析 。
“我们无意中发现小白鼠体内有两种属于黄酮类化合物的分子 。基本上来说，这些分子会向宿主脂肪组织发出信号，让它提取更多热量，获得更少脂肪 。”
“当这两种分子的数量下降时，脂肪就不会收到信号，体重就会反弹 。因此，在这种特殊情况下，我们采用的介入方法是通过食物和饮水来补充这两种缺失或被降解的分子 。当这两种分子的数量恢复到生理水平时，我们就彻底去除了体重反弹的倾向 。
谢谢大家收听科学美国人——60秒科学 。我是史蒂夫·米尔斯基 。
1. go back to 回到；
例句：She has gone back to her old habits.
2. in other words 换言之；换句话说；也就是说；
例句：In other words, we'd better change our plan.
3. come across 偶然发现；偶然遇见；
例句：I came across a group of children playing.
4. in this regard 在这方面；就这一点；
例句：In this regard nothing has changed.