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. 
  運動員難免要擔心自己的體重，自行車運動員尤其如此。練習賽上，到處都有人在討論怎樣減磅、增磅，和最新的飲食養(yǎng)生法和飲食時尚；各種健康飲食法層出不窮，又接連被推翻。我們都知道：在5%坡度（即2.25°）的斜坡上，超重10磅，爬坡時速就會下降0.5英里。這是有據可依的，根據牛頓第二定律：F=MA，蹬自行車所需的力與加速度和車座承受的質量成正比。

  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.
  跟我一起騎車的人大多和我一樣：四五十歲，有家有業(yè)，早就錯過了競賽的黃金期。我們騎車只是為了愉悅身心、保持健康，所以，何必為了一點點超重而耿耿于懷？不過，控制體重是自行車文化的一部分，而自行車文化是我們這個社會的縮影。飲食的控制遵循著自己的定律：食物的數(shù)量和味道，與吃下之后“犯罪感”的強烈程度成正比。

  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. 
  現(xiàn)在的問題是，人類從沒有像今天這樣，有如此豐富和珍貴的食物可以享用，我們又怎能抗拒這些美味的誘惑？美國南加州大學社會學教授巴里•格拉斯納（Barry Glassner）在他即將出版的新書《飲食信仰：你信奉的飲食規(guī)則都是錯的》中寫道，我們不應該拒絕美味，至少不應該完全拒絕。格拉斯納認為，人們錯誤地信奉著“不存在的真理”，竟然認為“一頓飯的價值取決于飯菜中缺少的成分：糖、鹽、脂肪、卡路里、碳水化合物、防腐劑、添加劑以及其他的可疑物質越少，飲食就越健康。”格拉斯納認為，這種飲食信條毫無科學性可言。

  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." 
  談到健康地吸收營養(yǎng)，味道的重要性就體現(xiàn)出來了。格拉斯納在書中引用了這樣一項研究：“面對同一道泰國菜，參與試驗的瑞典婦女都覺得味道太辣，而喜歡這道菜的泰國婦女則從中吸收到更多的鐵。相反，當自愿者享用漢堡包、馬鈴薯和豆子時，偏愛這類食物的瑞典婦女吸收的鐵更多。最值得注意的是第3項試驗，這一次，擺在自愿者面前的是營養(yǎng)價值很高，但淡而無味的糊狀物。在這種情況下，無論是泰國人，還是瑞典人，都沒能吸收到更多的鐵質。”

  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." 
  說到鐵，既然已經證明阿特金斯減肥法不利健康，是否該把肉類歸為危險食物呢？錯！格拉斯納在書中提到，研究證明，希臘人、意大利人和日本人的肉類消耗量和血膽固醇都在增長，但他們死于心臟病的幾率卻相對降低了。當然，在確定減肥和健康之間的因果關系時，我們無法排除其他因素的作用。格拉斯納提到的一項研究顯示，如果每天鍛煉30分鐘，不吸煙，多吃魚、纖維和葉酸（folate），心臟病突發(fā)的幾率就會降低28％；當然，還要盡量避免攝入飽和脂肪酸、反式脂肪酸（trans fat）以及讓葡萄糖水平驟升的碳水化合物。套用哈佛大學流行病學家卡琳•米歇爾斯（Karin Michels）的說法：“與減少非健康食物的常規(guī)攝入相比，增加健康食物的常規(guī)攝入更重要。”#p#分頁標題#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." 
  現(xiàn)在的健康問題更加復雜。格拉斯納在書中回顧了對心臟病、癌癥等多種疾病的研究，認為它們明顯是由“病毒和細菌感染、工作壓力、壓抑的生活環(huán)境，還有早年的一些不足，比如營養(yǎng)不良、出生時體重過低、缺少父母關愛，以及青春期和成人階段的慢性失眠”造成的。另一項研究顯示，這些疾病“在公眾參政率較低、種族歧視程度較高，或者貧富差距過大、男女收入不均的地方發(fā)生幾率更高”。

  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." 
  格拉斯納援引《新英格蘭醫(yī)學雜志》前任編輯馬西婭•安吉爾（Marcia Angell）的說法，進一步解釋這些數(shù)據：“盡管我們樂于相信，改變飲食習慣和生活方式能極大改善健康狀況，也不排除改善健康狀況的可能性。但除了某些特殊情況（例如戒煙），上述改變對健康的影響可能微弱而短暫。一份對某人無害的食譜，也許會對另一個人產生不良影響。”

  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."
  正如傳教士在《舊約•傳道書》第八章第十五節(jié)中所說：“我贊美歡笑，對一個人來說，陽光底下，沒有什么能比吃喝享樂更幸福了。”