df4型内燃机车:美国国家医学研究院的“营养标签”：优点、缺点及愚蠢之处

作者：大卫·凯茨（David Katz），医学博士，耶鲁预防研究中心主任

一个由美国国家医学研究院（以下简称“IOM”）授权，并由美国疾病控制中心、美国食品药品管理局和美国农业部资助的委员会，新近发布了有关包装正面营养标签的报告。这些建议可能有助于阻止食品行业干坏事，因此有其正面意义。不过，如果这些建议妨碍人们研究和推行更为优越的标签体系，那就是成事不足、败事有余了。更有甚者，这些建议还有彻头彻尾的愚蠢之处，因为……一会儿我们再细说。

The IOM began work on this issue in earnest, at the request of federal agencies, in the immediate aftermath of what can only be called the "Smart Choices debacle." 

IOM是应联邦机构的请求而开始致力于这项工作的，当时美国正处于所谓“聪明的选择大溃败”之后的余痛中。

Smart Choices was a front-of-pack nutrition guidance system developed by food industry elements, which famously reached the conclusion that Froot Loops was a "smart choice" for breakfast. That, among other things, invited some federal wrath, and the threat of punitive action by Congress, state attorneys general or both -- and the system was decommissioned. Food manufacturers had other front-of-pack systems prior, and have developed others since. Food industry elements, through the Food Marketing Institute and the Grocery Manufacturers Association, have recently rallied around "Nutrition Keys" -- which shifts back-of-pack information to the front.

“聪明的选择”（Smart Choices）是由一些食品行业业内人士开发的一套包装正面营养标签体系，曾经臭名昭著地认证家乐氏香果圈为早餐的“聪明选择”。这件事以及其它一些认证激怒了联邦政府，国会和首席州检察官都威胁要采取惩罚性措施，结果这套系统就解体了。在此之前，食品制造商曾经有过其它的包装正面标签体系，在此之后也曾开发过其它体系。透过食品营销协会和杂货制造商协会，食品行业近来开始呼吁“营养指标”，也就是把包装背面的信息移到正面。

Even as the food industry has attempted to regroup after Smart Choices, the IOM work on developing recommendations for consistent front-of-pack guidance has proceeded. 

就在食品行业试图在“聪明的选择”之后卷土重来时，IOM已经在着手研究如何在包装正面统一标签了。

The report just issued is lengthy. Its bulk alone, and its many citations, might suggest it is more definitive than it actually is. The IOM committee charged with this task, and its consultants, conducted no new research -- not even consumer focus groups. They cite prior literature with which all directly concerned with this field were already familiar. The large aggregation of studies cited attest to the fact that decisive evidence to indicate what nutrition guidance system is "best" has not yet been gathered. And thus the very report in which the IOM committee issues its recommendation makes clear that the recommendations are simply the opinion of a small group of people -- not based on directly relevant data.

刚刚发布的这份报告非常冗长。如果仅凭其厚度以及其中数量众多的引证，这份报告看起来相当具有权威性，而实际情况并不然。负责这项工作的IOM委员会及其顾问们并没有进行任何新的研究，甚至连组织消费者进行小组讨论都没有。他们援引的文献也都是跟这个领域直接相关的人士所早已熟知的。他们所引用的大量研究只是证明了一个事实，就是目前还没有确凿的证据证明，什么样的营养标签体系是“最好的”。因此，IOM委员会的建议报告显然只是少数几个人的意见而已，并没有直接相关的数据作为依据。

The committee's recommendations are, in essence, to note calories on the front of packs, and to provide a scale to indicate the relative quantity of added sugar, sodium, saturated fat and trans fat. It is not clear whether all of these nutrients will be bundled together into that scale, or whether each will be scaled separately. They suggest a numerical scale, ranging from 0 to 3.

简而言之，委员会的建议就是在包装正面注明卡路里，并提供了一套级别体系来标出添加糖、钠、饱和脂肪和反式脂肪的相对含量。文中并没清楚说明，所有这些营养成份是混在一起标出，还是需要分别列明。他们建议的级别体系是数字式的，从0到3。

Starting with the fact that this recommendation is based on nothing other than opinion, let's consider what's potentially good, potentially bad and potentially ugly about it.

鉴于这些建议完全是基于个人意见这一事实，咱们且来看看它们有哪些潜在的优点、哪些潜在的缺点，还有哪些潜在的愚蠢之处。

The Good:

优点：

The strength of the recommendation resides in its potential to constrain and unify the current efforts by food manufacturers to call out nutritional properties of their products to consumers. I fully respect that the business of business is business, and have no problem with food companies working to sell their food! But it is for that very reason that they should NOT be the ones to decide how to highlight nutritional quality -- because they will inevitably accentuate the positive. Food sellers deciding how to inform consumers about nutritional quality is a classic case of the fox guarding the hen house, and results in feather-flying fiascos like Smart Choices.

这些建议的好处在于，有可能因此而限制并统一目前食品制造商们想要向消费者宣传其产品中营养成份的种种做法。我完全理解生意就是生意，食品公司就是要卖食品的，这完全没问题！不过，也正是因为这个原因，才不应该由食品公司来决定营养成份的标识方法，因为它们难免要突出强调好的一面。由卖食品的来决定如何将食品中的营养成份告知消费者，就好像让狐狸来看鸡窝一样，结果肯定是类似“聪明的选择”那样鸡毛满天飞的闹剧。

The IOM recommendations tell manufacturers what is expected -- and while compliance with the expectations is voluntary, the heavy hand of regulation looms if compliance is poor. So the IOM report does promise to rein in the diverse efforts of food sellers to tell consumers a cherry-picked version of the truth about nutrition that is more about promoting sales than providing insights. That's good.

IOM的建议告诉食品制造商应该如何做。虽然照做与否完全由食品制造商自行决定，但是如果执行得太差，法规的重手还是可能会随之出击。卖食品的一直以各种方式只拣好的告诉消费者，它们所提供的各种版本的营养事实不是为了增强消费者的判断能力，而只是为了增加销售。现在，IOM的报告至少可以限制食品制造商的这些做法，这很好！

The Bad: 

缺点：

As already noted, the new recommendations are not the product of new research. They are simply a new opinion of a new group based on a limited assessment of the research to date. 

如上所述，这些新建议并不是基于新研究的成果，而只是一个新的工作小组对到目前为止已经做过的研究进行有限评估而作出的新结论罢了。

The group seemed to ignore the fact that the information they are proposing to put on the front of the pack is already on the back-of-pack in every case. Do we truly think that the fundamental limitation to consumers' ability to judge relative nutritional quality is their inability to turn the box around?

这个小组好象忽略了一个事实，就是他们建议放在包装正面的这些信息其实在包装背面已经都有了。我们难道真的以为，消费者之所以无法就相对营养价值作出判断，只是因为他们不知道把包装盒掉个个儿吗？

The group also seemed to ignore that a long history of efforts based on highlighting just negative nutrients have resulted in very poor food choices indeed. Warned against an excess of dietary fat, the public followed front-of-pack messages about 'low fat' to such questionable choices as SnackWell cookies. While accounting for several nutrients at a time may make similar missteps a bit less likely, there is much missed by simply noting what 'bad' stuff is or isn't in a food.

这个小组好象还忽略了一件事，那就是很久以来，我们一味强调负面的营养成份，这样做的结果导致了许多非常糟糕的食物选择。由于担心摄入过多的脂肪，公众便专门购买包装正面标有“低脂”的食物，甚至连SnackWell饼干【译者注：纳贝斯克公司的一个产品系列】这样令人质疑的选择也包括在内。虽然同时列出几种营养成份可能会减少同类错误的发生，但是仅仅标明食品中有或者没有什么“坏”东西，并不能全面说明问题。

Whether or not the new recommendations are proposing a 0 to 3 scale for each of several nutrients, or the several nutrients bundled together, a 0 to 3 scale is ... bad. It is bad because the average supermarket offers some 50,000 food items, and the US food supply offers a staggering variety of products, in the neighborhood of 800,000! These products range from marshmallows, jellybeans and fried pork rinds -- to spinach and kale. In between is everything from orange juice, kiwis, cauliflower, potatoes, salmon, chicken, beef, pizza, milk and margarine -- to milk chocolate, dark chocolate, avocado, walnuts, olives and blue cheese salad dressing. 

另外，不论这些新建议是要求从0到3把几种营养成份分别列出还是混在一起，从0到3这样的级别范围都非常糟糕。这是因为，一般超市销售的食物种类大约有五万种，而整个美国的食品供应种类更是五花八门，总数大约有八十万种！这些食品当中，从棉花糖、豆形软糖、炸猪皮到菠菜、甘蓝，应有尽有，还有橙汁、猕猴桃、菜花、土豆、三文鱼、鸡肉、牛肉、比萨饼、牛奶、植物奶油、牛奶巧克力、黑巧克力、牛油果、核桃、橄榄、蓝奶酪色拉酱等。

A 0 to 3 scale, one nutrient at a time, or several bundled together, risks truly massive compression of such diversity. If thresholds for points on such a scale are placed reasonably high, to safeguard health, an enormous percentage of processed foods will all get the same low score. When a large number of products get the same score, the system in question is providing no guidance when choosing among such products!

仅仅使用从0到3的级别尺度，不论是把营养成份分别标明还是打包标出，都意味着要把如此众多的食物种类加以大规模的压缩。如果为了保障健康而提高这一级别尺度上每一分的的门槛，则大量的加工食品都会得到同样的低分。当大量产品的得分都相同时，这一体系在人们选购食品时就无法提供任何指导。

Conversely, if the threshold for scaling is placed low enough so that a reasonable percentage of processed foods can "register" on the same scale as broccoli or spinach, then the ability to make distinctions at the high end of the scale is lost -- and products that are only moderately nutritious become indistinguishable from products that are really excellent. 

相反，如果级别尺度的门槛过低，使得相当一部分加工食品的得分都跟西兰花或菠菜一样，则该尺度在高端一侧对食品加以区分的能力又丧失了，那些只有一点儿营养的食物就跟真正优质的食品混在了一起。

There is no basis whatsoever in evidence for expressing the quality of nutrition for a supply of hundreds of thousands of foods across the limited expanse of 4 points. We don't get miles-per-gallon fuel efficiency ratings that way. We don't get wine quality scores that way. We don't score the SAT that way. Whenever there is a wide variation in a measure, a scale suitable to express it clearly and simply, but reliably, is warranted -- and routinely used. Efforts to date to express nutritional quality on a scale with just several values result in over 70 percent of all items in the supermarket getting the same score -- meaning, 7 times out of 10, such a system fails to help you make a choice.

要把成千上万种食品的营养价值仅仅依靠4分的跨度表达出来，这样的做法完全没有任何依据。我们用每加仑油跑多少英里来计算燃料效率时不是这样做的，葡萄酒的品质不是这样打分的，SAT考试【译者注：美国大学入学考试】的分数也不是这样算出来的。当实际量值存在大幅度的差异时，的确需要有一套清晰、简单、可靠、并且经得起再三使用的级别系统。如果要把营养成份仅仅通过有限的几个数值表达出来，超市里70%以上的食品就会有相同的得分，也就是说，10次当中有7次，这样一套体系将无法帮你作出选择。

There is another problem as well with so compressed a scale. One item at the very bottom of the nutritional quality barrel will get a 0 it well and truly deserves. Another will be much better, and nearly -- but not quite -- good enough to get a 1. It, too, will get a 0 -- and the difference will be invisible. Another item may barely qualify for a 3 -- and look exactly comparable to, say, spinach -- which is monumentally overqualified for that same 3! Again, a great deal of 'lumping' that conspires against the informed point-of-purchase choices such a system is supposed to empower.

如此压缩的级别尺度还有一个问题，就是虽然一种从营养价值角度来说完全处于箱子底的食物理所当然地会得0分，可是另一种好得多但是不够得1分的食物也会得0分，它们之间的差距将无从识别。一种食物可能只是勉强得了3分，看上去好像跟菠菜一样，可是菠菜得的那个3分含金量要高得多！级别尺度本来是要帮助人们在购买时进行选择，结果完全事与愿违，因为过多的食物被并入了一类。

Also bad is the fact that the IOM report is not directly linked to real-world evidence about what nutrition guidance systems can actually influence consumer choices for the better. And even more important, the committee apparently did not consider whether the nutrition guidance system actually translates into "better" food choices! The only true way to measure "better" food choices is to show that they correlate with better health outcomes -- since that is what the definition of "nutritious" derives from: foods that are health-promoting, and "good" for us. Absent evidence that food "scoring" for nutrition correlates with health outcomes, it is unsubstantiated opinion that a given scale reliably measures nutritional quality at all. Such evidence of the link between nutritional quality measurement and health outcomes has been published -- but the IOM report, quite surprisingly, ignores the issue entirely. This is clearly bad. The very goal of good nutrition guidance at point-of-purchase is to empower better health by moving in the direction of a better diet, one well informed choice at a time. 

还有一个糟糕的地方，就是到底什么样的营养标签体系能够真正影响消费者做出更好的选择，这类的实际依据在这份IOM报告当中完全没有任何体现。不仅如此，该委员会显然完全就没有考虑过，其所建议的营养标签体系是否会影响人们作出“更好的”食品选择！唯一能够真实地衡量食品选择是否变得“更好”的方法，就是证明其与改进的健康状况有相关性，因为“营养”本身就是这么定义的——那些有利于健康、对我们“有好处”的食物。如果没有证据证明，营养“得分”高的食品跟健康有相关性，一种级别尺度能够可靠衡量营养价值的说法就完全没有依据。有关营养成份指标与健康关联性的证据，以前曾经有人发布过，但是令人吃惊的是，IOM的报告竟然完全忽略了这个问题。这显然是一大缺陷。优良的营养标签体系的目标就是要帮助消费者在购买时做出更好的选择，朝更好的饮食方向迈进，从而更加健康。

The Ugly:

愚蠢之处：

But none of what's bad cited above rises to the level of truly "ugly."

虽然上面列出了许多缺点，但都还算不上真正“愚蠢”。

To get to truly ugly, we have to look at what ISN'T in the IOM recommendations! Fiber is not in the recommendations. Omega-3 oils are not in the recommendations. Antioxidant nutrients are not in the recommendations. Monounsaturated oils are not in the recommendations. Calcium is not in the recommendations. In fact, no beneficial nutrient, or nutrient property, is considered at all. 

要说明这份报告真正愚蠢的地方，我们就需要看看这些IOM建议里所缺少的东西！这些建议里没提到纤维，没提到欧米伽3脂肪酸，没提到抗氧化营养成份，没提到单不饱和脂肪酸，没提到钙。事实上，这些建议完全没有考虑任何有益的营养成份或营养价值。

There is no historical evidence that a nutritional guidance system based on 'negative' properties only is useful. The nutrition facts panel that is the mainstay of this space, developed during the tenure of Dr. David Kessler as FDA Commissioner, very explicitly includes positive and negative nutrients, and establishes a standard that should not be casually tossed aside.

没有任何证据证明，一套仅仅基于“负面”成份的营养标签体系能起什么作用。在大卫·凯斯勒博士担任美国食品药品管理局局长时编制的营养一览表是这个领域的主要支柱，里面明确包含了正面和负面的营养成份，这一标准不应被人随意搁置。

Imagine trying to sum up the health of a person with a short list of "negative" characteristics only. If you knew someone didn't use tobacco, didn't use illicit drugs, didn't run out into traffic without looking first and wasn't an alcoholic -- do you feel confident in your ability to say whether or not this person is actually healthy? I'm an expert in doing so, and I certainly don't -- nor would any other short list of just negative traits allow me to do so. A comprehensive blending of both negative and positive traits, however, reliably does -- and is the cornerstone of both all medical assessment, and the standardized Health Risk Appraisal.

你可以想象一下，如果仅仅使用少数几个“负面”特征来总结一个人的健康状况会是什么样子。如果你知道一个人不抽烟，不吸毒，不会看也不看地冲进汽车道里，也不酗酒，你是否有足够的把握来判定这个人实际健康与否呢？我是这方面的专家，可连我也做不到。即使把这些换成其它一些特征，但仅仅是负面特征，我还是无法做出判断。反过来，如果有比较全面的负面和正面特征，我们就能对一个人的健康状况做出比较可靠的判断，这是所有医学检查和标准化的健康风险评估的基石。

Trying to sum up overall nutritional quality by looking only at a short list of negative considerations is silly to the point of ... ugly.

仅仅依靠有限的几个负面因素，就想总结出食品的总体营养价值，这简直就是愚蠢到家了。

How ugly? Well, such a system would presumably have to give its highest commendation to a food that was free of all bad properties under consideration. Among the ranks of foods free of calories, added sugar, sodium, saturated fat, and trans fat -- diet soda springs to mind. A system that recognizes diet soda as a 'perfect' food is ... very ugly indeed.

这究竟愚蠢到了什么程度呢？按照这样一套体系，最高奖状应该发给那些没有任何所列坏成份的食品。在所有没有卡路里、添加糖、钠、饱和脂肪、反式脂肪的食物里，最先跳到我脑海里的就是无糖汽水。如果一套营养标签体系把无糖汽水认定为“最佳”食品，那真的是太愚蠢了。

And it is equally ugly in reverse. Walnuts are wonderfully nutritious -- but contain a bit of saturated fat, and quite a lot of calories. Avocado is highly nutritious, but also high in calories. Nut butters are very nutritious, but high in calories. Milk, unlike diet soda, contains sodium, calories and, if not fat-free, varying amounts of saturated fat. If the IOM intended to encourage diet soda intake as opposed to intake of milk, that's ... ugly.

反过来说也同样愚蠢。核桃营养非常丰富，但是含有少量饱和脂肪和相当不低的卡路里。牛油果也非常营养，但是卡路里含量也很高。坚果酱非常营养，但是卡路里含量也很高。跟无糖汽水不同，牛奶含有钠、卡路里，如果不是脱脂奶，还含有不同比例的饱和脂肪。如果IOM想要鼓励大家多喝无糖汽水少喝牛奶，那真的很愚蠢。

In Conclusion:

结论：

An IOM committee recommendation based on no new research, but just the opinion of one small group of advisors, is at best questionable -- particularly when it is at odds with the conclusions reached by other groups of those at least as highly qualified. 

一份没有任何新研究作为依据、仅仅靠几个顾问的个人意见所做出的IOM建议书，充其量也是令人怀疑的，尤其是当这份建议书跟其它同样高资质的研究小组所作出的结论相抵触时。

But whether the report proves to be of net benefit or harm to the public health will depend on how it is used. It will be good if used to prevent potentially harmful distortions that arise when the food sellers generate their own nutrition standards. It will be bad if it interferes with judgments in the court of public opinion about far more comprehensive approaches developed by independent entities committed to public health. And if it propagates the perception that high-calorie walnuts and almonds and avocado and yogurt are less good than 0-calorie diet sodas ... it will take ugly to a whole new place.

当然，这份报告对于公众健康最终是会带来好处还是坏处，完全取决于人们如何使用它。如果这份报告被用来防止那些卖食品的自行编制营养标准来混淆视听，那就是有益的。如果这份报告影响到大众对于那些致力于公共健康的独立团体所研发的更加完善的标签体系的看法，那就是有害的。如果这份报告的传播导致公众以为高卡路里的核桃、杏仁、牛油果和酸奶比不上零卡路里的无糖汽水，那就是愚不可及了。