Conventional wisdom about diets, including government health recommendations, seems to change all the time. And yet, ads routinely come about claiming to have "the answer" about what we should eat. So how do we distinguish what's actually healthy from what advertisers just want us to believe is good for us?
一般對於飲食的看法，包含政府的健康指南，似乎一直在改變。然而，廣告不斷聲稱擁有我們該吃什麼的「正確答案」。所以我們該如何辨別什麼飲食是真正健康的，而什麼又是廣告商想要我們信以為有益的呢？
Marketing takes advantage of the desire to drop weight fast, and be stronger, slimmer, and brighter. And in the big picture, diet plans promising dramatic results, known as "fad diets," are just what they seem: too good to be true. So where do diet fads even come from?
市場行銷利用人們想要快速減重，還有變得更強壯、纖瘦以及動人的渴望。而就整體看來，保證效果驚人的節食計劃，稱為「流行減肥飲食法」，它們的功效就和看起來一樣：好到不可能是真的。那麼流行減肥飲食法到底是從哪來的呢？
While the ancient Greeks and Romans rallied behind large-scale health regimens centuries earlier, this phenomenon began in earnest in the Victorian era, with crazes like the vinegar diet and the Banting diet. Since then, diets have advised us all sorts of things: to excessively chew, to not chew at all, to swallow a grapefruit per meal, non-stop cabbage soup, even consumption of arsenic, or tapeworms. If the idea of diet crazes has withstood history, could this mean that they work? In the short term, the answer is often "yes."
儘管古希臘和羅馬人早在幾世紀前就集結了大量的養生方法，這種現象要到維多利亞時代才真正開始，當時出現像吃醋節食法和班廷節食法這樣的風潮。自那時起，各種節食法就提供我們五花八門的建議：大量咀嚼、完全不要咬、每餐吞一顆葡萄柚、永無止境的捲心菜湯，甚至是吃砷，或絛蟲。如果節食風氣的概念能夠歷久不衰，這是不是可以代表它們有效呢？短期來看，答案常常是「有效」。
Low-carbohydrate plans, like the popular Atkins or South Beach diets, have an initial diuretic effect. Sodium is lost until the body can balance itself out, and temporary fluid weight loss may occur. With other high-protein diets, you might lose weight at first since by restricting your food choices, you are dropping your overall calorie intake. But your body then lowers its metabolic rate to adjust to the shift, lessening the diet's effect over time and resulting in a quick reversal if the diet is abandoned. So while these diets may be alluring early on, they don't guarantee long-term benefits for your health and weight.
低碳水化合物飲食，像是受歡迎的阿金減肥法和南灘飲食法，最初都會有利尿的效果。鈉含量流失，直到身體自己可以平衡為止，而短暫因水分流失的體重下降就有可能發生。採用其它高蛋白飲食，你可能一開始體重會掉，因為藉由限制食物選擇，你讓整體卡路里攝取量下降。不過你的身體接著會降低基礎代謝率來適應這種變化，隨著時間過去讓節食的效果變小，且如果放棄這種飲食的話還會導致體重快速回升。所以儘管這些節食法一開始可能都很誘人，它們並不保證對你的健康和體重有長期的好處。
A few simple guidelines, though, can help differentiate between a diet that is beneficial in maintaining long-term health and one that only offers temporary weight changes. Here's the first tip-off: If a diet focuses on intensely cutting back calories or on cutting out entire food groups, like fat, sugar, or carbohydrates, chances are it's a fad diet. And another red flag is ritual, when the diet in question instructs you to only eat specific foods, prescribed combinations, or to opt for particular food substitutes, like drinks, bars, or powders. The truth is shedding pounds in the long run simply doesn't have a quick-fix solution.
不過有幾個簡單的原則，可以幫你分辨什麼是對維持長期健康有益的飲食，和什麼是只讓體重短時間內有變化的飲食。這裡是第一個情報：如果一種飲食法專注在大量減少卡路里或排除整個食物群，像是脂肪、糖或碳水化合物，那很可能就是種流行減肥飲食法。另一個警告紅旗是不變的模式，也就是當討論的飲食計劃指示你只能吃特定食物、規定的組合，或選擇特定食物替代品時，像是飲品、食物棒，或粉狀食物。事實就是，要長期減重並沒有什麼快速簡易的方法。
Not all diet crazes tout weight loss. What about claims of superfoods, cleanses, and other body-boosting solutions? Marketing emphasizes the allure of products associated with ancient and remote cultures to create a sense of mysticism for consumers. While so-called superfoods, like blueberries or acai, do add a powerful punch of nutrients, their super transformative qualities are largely exaggeration. They are healthy additions to a balanced diet, yet often, they're marketed as part of sugary drinks or cereals, in which case the negative properties outweigh the benefits. Cleanses, too, may be great in moderation since they can assist with jump-starting weight loss and can increase the number of fresh fruits and vegetables consumed daily. Scientifically speaking, though, they've not yet been shown to have either a long-term benefit or to detox the body any better than the natural mechanisms already in place.
並非所有流行飲食法都以減重為賣點。那麼那些聲稱是超級食物、排毒療法，還有其它促進身體機能的方法呢？市場行銷將重點擺在產品和古代與久遠文化連結所產生的吸引力，以讓消費者產生一種神祕感。雖然所謂的超級食物，像是藍莓或巴西莓，確實會讓營養大增，但它們的超強改變能力大部分是言過其實。它們是加到均衡飲食中的健康添加物，然而經常，它們被當作含糖飲料或穀片的成分來銷售，那樣的話壞處就大過好處了。排毒療法也是，適度採取這種方式可能很好，因為它們可以幫助我們開始減重，還能增加每日攝取的新鮮蔬果量。不過就科學的角度來說，它們都尚未被證實有長期的好處，或能比身體本來就有的天然機制有更棒的排毒功能。
Everywhere we look, we're offered solutions to how we can look better, feel fitter, and generally get ahead. Food is no exception, but advice on what we should eat is best left to the doctors and nutritionists who are aware of our individual circumstances. Diets and food fads aren't inherently wrong. Circumstantially, they might even be right—just not for everyone all of the time.
無論我們看哪，都有讓我們看起來更棒、感覺更健康，還有整體上獲得成功的方法。食物也不例外，不過對於我們該吃什麼的建議最好是留給醫師和營養師來提供，他們才知道我們的個人情況。節食法和流行食物不是本來就有錯。視情況而言，它們甚至有可能是對的－－只是不是對每個人都對。
