Among athletes who obsess about their weight, we cyclists are second to none. Training rides are filled with conversations about weight lost or gained and the latest diet regimens and food fads. Resolutions are made and broken. We all know the formula: 10 pounds of extra weight on a 5 percent grade slows your ascent by half a mile an hour. It has a ring of Newtonian finality to it. F = MA. The Force needed to turn the pedals equals Acceleration times that Mass on the saddle. 
  运动员难免要担心自己的体重，自行车运动员尤其如此。练习赛上，到处都有人在讨论怎样减磅、增磅，和最新的饮食养生法和饮食时尚；各种健康饮食法层出不穷，又接连被推翻。我们都知道：在5%坡度（即2.25°）的斜坡上，超重10磅，爬坡时速就会下降0.5英里。这是有据可依的，根据牛顿第二定律：F=MA，蹬自行车所需的力与加速度和车座承受的质量成正比。

  But most of the guys I ride with are like me: in their 40s and 50s with jobs and families, long past racing prime. We ride because it is fun, and it feels good to be fit. So why obsess over a few pounds? Because that is the cycling culture--emblematic of our society at large--and it carries its own internal calculus: the amount of guilt is directly proportional to the rise in the quantity and tastiness of the food.
  跟我一起骑车的人大多和我一样：四五十岁，有家有业，早就错过了竞赛的黄金期。我们骑车只是为了愉悦身心、保持健康，所以，何必为了一点点超重而耿耿于怀？不过，控制体重是自行车文化的一部分，而自行车文化是我们这个社会的缩影。饮食的控制遵循着自己的定律：食物的数量和味道，与吃下之后“犯罪感”的强烈程度成正比。

  The problem is that our bodies have evolved to crave copious amounts of rich and tasty foods, because historically such foods were valuable and rare. How can we modern humans resist? We shouldn't, at least not entirely, says Barry Glassner, a University of Southern California sociologist and author of the forthcoming book The Gospel of Food: Everything You Think You Know about Food Is Wrong (Ecco). We have wrongly embraced what Glassner calls "the gospel of naught," the view that "the worth of a meal lies principally in what it lacks. The less sugar, salt, fat, calories, carbs, preservatives, additives, or other suspect stuff, the better the meal." The science behind this culinary religion, Glassner says, is close to naught. 
  现在的问题是，人类从没有像今天这样，有如此丰富和珍贵的食物可以享用，我们又怎能抗拒这些美味的诱惑？美国南加州大学社会学教授巴里•格拉斯纳（Barry Glassner）在他即将出版的新书《饮食信仰：你信奉的饮食规则都是错的》中写道，我们不应该拒绝美味，至少不应该完全拒绝。格拉斯纳认为，人们错误地信奉着“不存在的真理”，竟然认为“一顿饭的价值取决于饭菜中缺少的成分：糖、盐、脂肪、卡路里、碳水化合物、防腐剂、添加剂以及其他的可疑物质越少，饮食就越健康。”格拉斯纳认为，这种饮食信条毫无科学性可言。

  When it comes to healthy absorption of nutrients, taste matters. Glassner cites a study in which "Swedish and Thai women were fed a Thai dish that the Swedes found overly spicy. The Thai women, who liked the dish, absorbed more iron from the meal. When the researchers reversed the experiment and served hamburger, potatoes, and beans, the Swedes, who like this food, absorbed more iron. Most telling was a third variation of the experiment, in which both the Swedes and the Thais were given food that was high in nutrients but consisted of a sticky, savorless paste. In this case, neither group absorbed much iron." 
  谈到健康地吸收营养，味道的重要性就体现出来了。格拉斯纳在书中引用了这样一项研究：“面对同一道泰国菜，参与试验的瑞典妇女都觉得味道太辣，而喜欢这道菜的泰国妇女则从中吸收到更多的铁。相反，当自愿者享用汉堡包、马铃薯和豆子时，偏爱这类食物的瑞典妇女吸收的铁更多。最值得注意的是第3项试验，这一次，摆在自愿者面前的是营养价值很高，但淡而无味的糊状物。在这种情况下，无论是泰国人，还是瑞典人，都没能吸收到更多的铁质。”

  Speaking of iron, Atkins is out and meat is bad, right? Wrong. Glassner notes a study showing that as meat consumption and blood cholesterol levels increased in groups of Greeks, Italians and Japanese, their death rates from heart disease decreased. Of course, many other variables are involved in determining causal relations between diet and health. Glassner cites a study showing a 28 percent decrease in risk of heart attacks among nonsmokers who exercised 30 minutes a day, consumed fish, fiber and folate; they also avoided saturated fats, trans fats and glucose-spiking carbs. According to Harvard University epidemiologist Karin Michels, "It appears more important to increase the number of healthy foods regularly consumed than to reduce the number of less healthy foods regularly consumed." 
  说到铁，既然已经证明阿特金斯减肥法不利健康，是否该把肉类归为危险食物呢？错！格拉斯纳在书中提到，研究证明，希腊人、意大利人和日本人的肉类消耗量和血胆固醇都在增长，但他们死于心脏病的几率却相对降低了。当然，在确定减肥和健康之间的因果关系时，我们无法排除其他因素的作用。格拉斯纳提到的一项研究显示，如果每天锻炼30分钟，不吸烟，多吃鱼、纤维和叶酸（folate），心脏病突发的几率就会降低28％；当然，还要尽量避免摄入饱和脂肪酸、反式脂肪酸（trans fat）以及让葡萄糖水平骤升的碳水化合物。套用哈佛大学流行病学家卡琳•米歇尔斯（Karin Michels）的说法：“与减少非健康食物的常规摄入相比，增加健康食物的常规摄入更重要。”#p#分页标题#e#

  It's more complicated still. Glassner reviews research showing that heart disease, cancer and other illnesses are significantly increased by "viral and bacterial infections, job stress, living in distressed neighborhoods, early deficits such as malnutrition, low birth weight, lack of parental support, and chronic sleep loss during adolescence and adulthood." Another study found that such diseases "are higher in states where participation in civic life is low, racial prejudice is high, or a large gap exists between the incomes of the rich and poor and of women and men." 
  现在的健康问题更加复杂。格拉斯纳在书中回顾了对心脏病、癌症等多种疾病的研究，认为它们明显是由“病毒和细菌感染、工作压力、压抑的生活环境，还有早年的一些不足，比如营养不良、出生时体重过低、缺少父母关爱，以及青春期和成人阶段的慢性失眠”造成的。另一项研究显示，这些疾病“在公众参政率较低、种族歧视程度较高，或者贫富差距过大、男女收入不均的地方发生几率更高”。

  To clarify this cornucopia of data, Glassner quotes the former editor of the New England Journal of Medicine, Marcia Angell: "Although we would all like to believe that changes in diet or lifestyle can greatly improve our health, the likelihood is that, with a few exceptions such as smoking cessation, many if not most such changes will produce only small effects. And the effects may not be consistent. A diet that is harmful to one person may be consumed with impunity by another." 
  格拉斯纳援引《新英格兰医学杂志》前任编辑马西娅•安吉尔（Marcia Angell）的说法，进一步解释这些数据：“尽管我们乐于相信，改变饮食习惯和生活方式能极大改善健康状况，也不排除改善健康状况的可能性。但除了某些特殊情况（例如戒烟），上述改变对健康的影响可能微弱而短暂。一份对某人无害的食谱，也许会对另一个人产生不良影响。”

  As the preacher said in Ecclesiastes 8:15: "Then I commended mirth, because a man hath no better thing under the sun, than to eat, and to drink, and to be merry."
  正如传教士在《旧约•传道书》第八章第十五节中所说：“我赞美欢笑，对一个人来说，阳光底下，没有什么能比吃喝享乐更幸福了。”