还没有看过上半部分的，请先补看一下：
增肌与蛋白质的关系，运动员到底需要多少蛋白质？（上）
蛋白质与运动员的完整视频在这里：
现在我们知道蛋白质摄入量本身并不能刺激肌肉生长，然而这些年来动物被注射了大量的类固醇和生长激素，他们使用这些激素使动物长得更大，以获得更多利润。
Now we know that protein intake does not stimulate muscle growth per se, however animals these days are shot full of steroids and growth hormones that they use to make the animals grow bigger so they can sell better.
当我们摄取肉时，实际上是摄入了类固醇和/或生长激素，这可能会刺激我们的肌肉生长。
When we ingest their meat, we are in effect ingesting steroids and/or growth hormones, which may stimulate our muscle growth.
此外，动物蛋白，乳蛋白是主要的罪魁祸首，其显著增加已知的刺激细胞生长的胰岛素样生长因子 1 或 IGF-1。
Furthermore, animal protein, dairy protein being a major culprit here, has been shown to significantly increase insulin-like growth factor 1 or IGF-1, which is known for stimulating cell growth.
这可能听起来很棒，因为它可能会增加肌肉量，但它也刺激我们不喜欢的另类生长，如癌症，衰老和痤疮。
This may sound great because it may increase muscle mass, but it also stimulates other growth that we don’t like such as cancer, aging, and acne.
因此如果我们的目标是保持健康，那么就不希望以这种方式来刺激生长。
So if our goal is to be healthy, then we don’t want to stimulate growth that way.
我们应该只是坚持肌肉负荷训练方法，然后试着对基因决定的通过健康的增肌过程获得的肌肉量感到满意。
We should stick to muscle-loading only, and then try to be comfortable with how big our genes allow us to get through a healthy muscle-building process.
如果我们想要肌肉变得更大，那么必须考虑刺激生长药物对健康的影响，但除了药物之外，其他任何东西都不会真正起作用，包括过量的蛋白质摄入量。
If we want to get even bigger, then we have to consider the impact growth-stimulating drugs will have on our health, but aside from the drugs, nothing else will really make a difference, including excessive protein intake.
运动表现甚至更难以衡量，尽管专家们将其作为推动他们通常销售的蛋白质补充剂的动力。
Athletic performance is even more difficult to measure, although experts use this as their impetus to recommend their protein supplements that they are usually selling.
他们给出理论或还原论的解释，说明他们的建议如何在身体中起作用，但并未证明这种机制是真实的，与其他干预措施相比，在实际研究中也没有证明有益处。
They give a theoretical or reductionist explanation of how their recommendations should work in the body but have not proven this mechanism to be true, nor the benefits to exist in actual study compared to other interventions.
我希望看到这样的研究试图使用较少的蛋白质或其他潜在更好的食物，例如 100％ 不含蛋白质补充剂的全食物，高水果量以提供更简单的能量，以及一个对比组。
I want to see the study trying to use less protein or other potentially better food, such as a 100% whole foods diet without protein supplements, high in fruits for more simple energy, and a comparison group.
为什么这些数据缺乏？ 我不知道。 换句话说，你不会知道较少的蛋白质更好或至少是相同的，直到它在相同的运动场上进行试验和比较。
Why is this data lacking? I don’t know. In other words you won’t know that less protein is better or at least equivalent until it is tried and compared on equal playing fields.
耐力运动员的蛋白质含量超过 10％ 表现更差的研究使得我担心许多运动员可能会因为他们巨大量的蛋白质补充剂而走上错误的轨道，无论它来自动物还是植物。
The study of endurance athletes doing worse with more than 10% protein makes me concerned that many athletes may be on the wrong track with their huge protein supplements, and that’s no matter whether it comes from an animal or a plant.
此外，您不会了解摄取大量提纯的蛋白质补充剂的实际危害，直到与大量人群或相当数量的人群长时间摄取较低水平的蛋白质相比较。但是如果运动员如此害怕蛋白质缺乏，我们怎么能做测试呢？
Furthermore, you won’t know about the actual harms of consuming high levels of extracted protein supplements until this is compared in large, otherwise equivalent groups of people for long periods of time, who are consuming lower levels of protein. But how can we even test this if athletes are so scared of being protein-deficient?
我发现运动员补充蛋白质的领域非常主观，通常是基于专家给出的他们自己臆想的证据和经验的建议。
I find the area of athlete protein supplementation to be very subjective with recommendations often based on experts giving their own anecdotal evidence and experience.
吃大量的任何类型的提纯蛋白质都有潜在危害。过量的蛋白质就是过量的蛋白质，无论是来自动物还是植物。
Eating high levels of any type of extracted protein is potentially harmful. Excess protein is excess protein, whether it comes from animals or plants.
过量的蛋白质会对肝脏、肾脏和骨骼造成压力。
And excess protein stresses the liver, the kidneys, and bones.
那么从植物中获取蛋白质显然比从动物来源获得的更健康，就环境污染物，胆固醇，饱和脂肪而言都是要考虑的问题，而一旦你将任何食物中的蛋白质提取出来，就会将食物变成毒药，一旦这样做了，只有潜在的危害而没有可靠的证据证明有益处。
Now getting your protein from plants is clearly healthier than getting it from animal sources, as far as environmental contaminants, cholesterol, saturated fat, are all concerned, but once you take any food and extract the protein, you are turning a food into a drug, and once this is done, there is the potential for harm without good evidence of benefit.
例如，大豆分离蛋白实际上比乳制品蛋白增加更多胰岛素样生长因子或 IGF-1。 接下来的一点有望帮助我们获得蛋白质需求的全局观点。
For example, isolated soy protein actually increases insulin-like growth factor or IGF-1 more than dairy protein. This next point will hopefully help get protein requirements in perspective.
当人长身体的时候对蛋白质需求量最大（按热量百分比），因为在构建新的组织，并且确实，随着体重增加，举重者的肌肉会增长，但正如我所说的，植物性饮食中的蛋白质已经提供了 10-15％ 的热量，而美国式饮食中的蛋白质还要更多。
A human has the highest need for protein as a percentage of calories when it is growing, as that is when it is building up new tissue, and it is true that muscle grows in weight lifters as they get bigger, but as I said, we already get 10 to 15% of our calories from protein on a plant-based diet, and even more than that on the American diet.
有太多过量的蛋白质，当举重时，我们不需要做任何不同的事情，除了在饥饿时吃更多相同的全食物。
There’s so much excess protein that we don’t need to do anything differently when we lift weights, other than eat more of the same whole foods when we’re hungry.
记住食欲随运动而增加，所以运动时我们也会吃更多的食物，这会增加总蛋白质摄入量。
Remember our appetite increases with exercise, so we will also eat more food when we exercise, which increases our overall protein intake.
话虽如此，你认为我们什么时候生长最快，按体重增加的百分比计算？
That being said, when do you think we are growing the most as far as a percentage of body weight?
当我们刚刚出生时。
When we are first born.
因此，如果大自然规划食物以获得最高的蛋白质百分比，那么大自然在生命的哪个阶段会使蛋白质含量最高？也就是说，我们什么时候需要食物中蛋白质的比例最高？
So if nature was manipulating food to have the highest protein percentage, at what point in life would nature have made protein levels be the highest? That is, when would we need our percentage of protein in our food to be the highest?
当我们体重加倍的时候。
When we’re doubling in size.
所以当一个婴儿体重增加一倍，需要最高的蛋白质百分比，母乳是首选的食物，而单靠母乳人就可以茁壮成长，因此人类母乳中有多少百分比的热量是从蛋白质而来的？
So when a baby is doubling in size, requiring the highest percentage of protein, human breastmilk is the food of choice, and humans thrive on this diet of breastmilk, so what percentage of calories of human breastmilk is protein?
5%，人类母乳中只有 5% 的热量是从蛋白质而来的，而这已经足够让人类（婴儿）体重加倍。
Five percent, only 5% of the calories of human breastmilk are protein, and that is enough to allow humans to double in size.
燕麦的蛋白质含量超过 15％，我们当然不需要在食用时增加一倍的体重。
Oats are over 15% protein, and we certainly don’t need to be doubling in size by the time we’re eating them.
所以从很多不同的角度来说，蛋白质争论对我来说根本不是问题。
So from many different angles, the protein argument doesn’t make sense to me.
然而，包括运动员在内的很多人都因为某种原因担心蛋白质。
Yet so many people, including athletes are so worried about protein for some reason.
更有甚者，我们都愿意吞下没有通过黄金标准评估的分离蛋白粉。首先，他们（指售卖蛋白粉的公司）需要证明在健康蔬食的前提下，（不吃蛋白粉的话）人们不会提起同样的重物或有同样体能表现，所以他们需要证明（不吃蛋白粉）会有问题。（译注：因为演讲比较口语化，翻译时增加省略的词。）
What’s more, we’re all willing to swallow isolated protein powders that have not been through the gold standard critical appraisal. First they need to show that on a healthy plant-based diet, people won’t lift as much weight or perform as well, so they need to show there is a problem.
请记住，他们需要客观地评估运动表现，从全局角度把人们对于运动表现不佳的主观抱怨先放在一边。
And remember, they need to objectively evaluate performance, keeping people’s subjective complaints of poor performance in perspective.
然后他们需要尝试做干预试验。 他们还需要研究火麻仁蛋白粉补充剂多年，或者至少只要有人吃补充剂来证明补充蛋白质没有发现任何危害，即使它可以提高运动表现。
Then they need to try the intervention. They also need to study the hemp protein powder supplement for years, or at least as long as someone will take these supplements to prove that there is no harm found with the protein supplement even if it winds up improving performance.
至少，运动员可以决定，提早 45 分钟完成比赛而增加今后 10 年的癌症风险是否值得，那么如果没有发现伤害，他们仍然必须告诉人们可能存在伤害，即使在这个特定的研究中没有一个伤害被发现，所以一项研究发现一种物质是安全的并不意味着伤害不存在。
At least then the athletes could decide if finishing their race 45 minutes faster is worth the increased cancer risk 10 years from now, and then if no harm was detected, they still have to tell people that there may be harm, but that none was elicited in this particular study, so one study finding that a substance is safe doesn’t mean that harm doesn’t exist.
不如说是，这意味着研究人员在研究过的这段时间内无法找到伤害。如果由蛋白质补充剂刺激引起的癌症需要 15 年才能发现，又如何呢？
Rather it just means that harm couldn’t be found in that study population over that period of time studied. What if the cancer caused by the protein supplement stimulation takes 15 years to detect?
一项对 25 岁运动员的研究不会显示出伤害，直到 40 岁时才会显示出，当这项研究在他们开始服用（蛋白质）补充品五年后出版，我们是无法得知是否有伤害的。
A study of athletes age 25 won’t show harm until age 40, we won’t know that when this study is published five years after they started taking the supplement.
我并不是说每个人在服用补充剂之前都需要做这个评估，但是人们需要知道蛋白质粉补充剂的宣称益处是基于传闻还是无可辩驳的数据，以便他们被真实告知一切后做出决定。
I’m not saying that everyone needs to do this evaluation before taking a supplement, but people need to know whether the proposed benefits of a protein powder supplement are based on anecdotal evidence or incontrovertible data so that their decision can truly be informed.
（ 翻译及编辑：老玉米 ）
参考文献：
Craig WJ, Mangels AR, American Dietetic Association. Position of the American Dietetic Association: vegetarian diets. J Am Diet Assoc 2009 Jul; 109(7): 1266-82.
Food & Agriculture Organization. (2001). Human Energy Requirements Report of a Joint FAO/WHO/UNU Expert Consultation. Retrieved from: Italy. http://www.fao.org/docrep/007/y5686e/y5686e08.htm#bm08.
Lappe FM. Diet for a Small Planet. New York, NY, Ballantine Books. 1985.
McDougall J. The McDougall Plan. LaVerne TN, Ingram Book Company. 1983.
Osborn TB, Mendel LB. Amino Acids in Nutrition and Growth. J Biol Chem 1914; 17: 325.
World Health Organization. (2007). Protein and Amino Acid Requirements in Human Nutrition: Report of a Joint WHO/FAO/UNU Expert Consultation. Retrieved from: http://whqlibdoc.who.int/trs/WHO_TRS_935_eng.pdf.
译后记：马特·莱德曼医生关于运动员与蛋白质的讲解全部看完了，你对蛋白质还有疑问吗? 或者还有其它蔬食营养方面的问题吗？
欢迎加入“蔬食益生微信交流群”。
蔬食益生”公众号是3月底才申请的，根据国家法律法规和平台规则要求，新注册账号无留言功能。
蔬食益生微信交流群”，方便大家互动互助，有兴趣的朋友请添加管理员的微信拉你进群：vegan_lin, 添加注明暗号“蔬食益生”。
德国美女大学生 丽萨 用中文特别推荐符合 “低脂全蔬食” 原则的健康食谱公众号：
— 想吃得健康，又不想放弃口福？这里有办法！
医生亲自示范最喜欢的全食物健康甜品 “ 抹茶冰淇淋 ”做法（内有 “ 蔬食益生微信交流群” 管理员 “ 食素者也 ” — “ 标哥 ” 的介绍，他通过”低脂全蔬食“成功逆转了三高。）
：
延伸阅读：吃素是技术活儿？《救命》作者Michael Greger 医生手把手教你怎么吃最有营养！
Michael Greger 医生畅销书《How Not To Die》简体中文版《救命》今年5月出版，点此了解详情。（友情链接，老玉米不参与书的销售）
关于编译者：老玉米是美国康奈尔大学坎贝尔营养研究中心《蔬食营养》证书持有者。老玉米的先生是美国内科医生(MD)，也是位“蔬食医生”(Plantrician)。
蔬食益生”公众号，会有更多精彩内容。
老玉米衣食无忧，退休金也准备好了，开这个公众号纯粹是吃饱了撑的。
您的点赞和转发是老玉米继续工作下去的动力！
！本公众号是纯信息分享。