#097 蛋白质科学及其在长寿、癌症、衰老和增肌中的作用

欢迎收听今天的节目，本期内容对任何想要最大化训练效果的人来说都将是特别的一期。

Welcome to today's episode, which promises to be exceptional for anyone aiming to maximize their training outcomes.

我们将深入探讨蛋白质的科学，这是实现健身目标的关键要素。

We are going deep into the science of protein, a crucial element in achieving your fitness goals.

随本期节目附赠的是一份新的《Found My Fitness》指南，名为《如何按照专家建议训练》。

Accompanying this episode is a new Found My Fitness guide titled How to Train According to the Experts.

这份全面指南不仅涵盖你今天将学到的所有内容，还解答了关于如何最佳训练、饮食和补充营养以获得最佳效果的关键问题。

This comprehensive guide not only encompasses everything you'll learn today, but also tackles key questions on how to best train, eat, and supplement for optimal results.

它综合了全球顶尖专家在训练、营养和补充剂方面的最佳建议，这些专家在本节目近100期内容中都有过分享。

It synthesizes the best advice on training, nutrition, and supplementation from the world's leading experts featured across nearly 100 episodes of this show.

我强烈建议你免费下载这份指南，网址是howtotrainguide.com。

I highly encourage you to download this free guide at howtotrainguide.com.

再次提醒，网址是howtotrainguide.com。

Once again, that's howtotrainguide.com.

现在让我们继续本期关于蛋白质科学的节目内容。

Now let's proceed with the episode on the science of protein.

除了众所周知的作为肌肉构建基础的作用外，蛋白质对我们的新陈代谢、胰岛素敏感性以及预防如2型糖尿病和肌肉减少症等疾病至关重要。

Beyond its well known role as the building block of muscle, protein is fundamental to our metabolism, insulin sensitivity, and the prevention of diseases such as type two diabetes and sarcopenia.

但我们究竟需要多少膳食蛋白质？

But how much dietary protein do we really need?

而过多的蛋白质，尤其是来自肉类的，是否可能有害？

And could too much protein, especially from meat, actually be harmful?

今天，我们将讨论为什么维持甚至增肌对每个人都至关重要，而不仅仅是运动员。

Today, we'll discuss why maintaining and even building muscle is critical for everyone, not just athletes.

你将了解蛋白质摄入结合抗阻训练如何驱动肌肉修复与生长，从而提升运动表现、改善代谢健康，并通过抵御年龄相关的衰弱来促进长寿。

You'll discover how protein intake coupled with resistance training drives muscle repair and growth, enhancing athletic performance, improving metabolic health, and promoting longevity by acting as a defense against age related frailty.

你将学习基于年龄、活动水平和目标的最佳蛋白质摄入量，无论你是想积极增肌、维持肌肉还是仅改善体成分。

You'll learn about optimal protein amounts based on age, activity level, and goals, whether you want to actively gain muscle, maintain it, or just improve body composition.

我们将批判性地审视当前的蛋白质推荐量，质疑每公斤体重0.8克的RDA标准是否足够。

We will critically examine current protein recommendations, challenging the adequacy of the RDA of 0.8 grams per kilogram body weight.

基于最新研究，我们将探讨为什么1.2至1.6克/公斤的更高摄入量对整体健康更有利，以及为什么高达2克或更多可能最有利于身体重组。

Drawing on the latest research, we discuss why higher intakes ranging from one point two to one point six grams per kilogram are more beneficial for general health and why up to two grams or higher may be best for body recomposition.

针对高蛋白饮食与健康风险之间的争议性关联，我们将分析蛋白质与癌症、心脏病及肾功能关系的相关证据。

Addressing the contentious links between high protein diets and health risks, we will analyze evidence surrounding proteins association with cancer, heart disease, and kidney function.

我们将探讨生活方式因素，特别是体育活动如何深刻影响这些风险。

We'll explore how lifestyle factors, particularly physical activity, profoundly influence these risks.

具体而言，我们将揭示运动如何调节IGF-1等生长因子，将其导向肌肉和脑组织以支持修复与生长，同时可能减轻它们在其他组织的促癌效应。

Specifically, we'll uncover how exercise modulates growth factors like IGF-one, diverting them towards muscle and brain tissue where they support repair and growth while potentially mitigating their pro cancer effects in other tissues.

我们将剖析动物蛋白与植物蛋白在刺激肌肉蛋白质合成方面的差异。

We dissect the differences between animal and plant proteins in stimulating muscle protein synthesis.

我们将为素食者和纯素食者提供实用策略，通过增加总摄入量、多样化来源和使用植物蛋白浓缩物来有效满足蛋白质需求。

We'll provide practical strategies for vegetarians and vegans to meet their protein needs effectively through increased total intake, diversified sources, and the use of plant based protein concentrates.

我们还将破除关于蛋白质摄入时机的迷思。

We'll also dispel myths around protein intake timing.

您将了解如何通过均匀分配三餐蛋白质摄入来最大化肌肉蛋白质合成，以及为何所谓的运动后合成代谢窗口期可能不像曾经认为的那样短暂。

You'll learn how distributing protein evenly across meals can maximize muscle protein synthesis and why the so called post exercise anabolic window may not be as narrow as once thought.

此外，我们强调氨基酸亮氨酸在激活肌肉构建通路中的关键作用，以及这对蛋白质质量考量的影响。

Additionally, we highlight the pivotal role of the amino acid leucine in activating muscle building pathways and how this impacts protein quality considerations.

在本期节目结束时，你将掌握所有基于证据的见解，帮助你更好地应对常见误解，最终利用蛋白质实现肌肉维持、提升表现并拥有一个远离衰弱的未来。

By the end of this episode, you'll be equipped with all of the evidence based insights you need to better navigate common misconceptions and ultimately harness protein for muscle maintenance, performance, and a frailty free future.

那么让我们开始吧。

So let's get into it.

我们拥有的肌肉量比体重或BMI更能揭示我们的衰老状况。

How much muscle we have tells us more about how we are aging than body weight or BMI ever could.

这里有一个惊人的事实。

Here's a startling fact.

50岁后，普通人每年会流失约1%的肌肉量。

After the age of 50, the average person loses about 1% of their muscle mass every single year.

不仅是肌肉量的问题。

And it's not just muscle mass.

力量下降得更快，每年约减少3%。

Strength plummets even faster, dropping around 3% annually.

到75岁时，如果不进行定期力量训练，每年力量流失可能高达4%。

By the time you reach 75, if you're not engaging in regular strength training, you could be losing up to 4% of your strength every year.

那么，我们能对此做些什么呢？

So what can we do about this?

锻炼，既要在需要之前进行以储备肌肉，也要在老年时期进行以减缓并逆转衰退。

Exercise, both before you need it, building muscle reserve, but also in old age to slow and reverse the decline.

虽然抗阻训练是构建和维持肌肉质量与力量的最重要因素，蛋白质摄入也起着重要作用。

While resistance training is the most important factor for building and maintaining muscle mass and strength, protein intake plays an important role too.

来自斯图尔特·菲利普斯博士及其同事的一项荟萃分析强调了蛋白质摄入的重要性，研究表明，

A meta analysis from Doctor.

那些进行抗阻训练并额外补充蛋白质的人，将每日蛋白质总摄入量提高到每公斤体重1.6克，他们的肌肉质量增加了27%，力量比未补充蛋白质仅进行抗阻训练的人高出10%。

Stuart Phillips and colleagues highlights the importance of protein intake by showing that people who engage in resistance training and supplemented with additional protein taking their total daily protein intake up to 1.6 grams per kilogram body weight increased their muscle mass by 27% and their strength by 10% more than those who did resistance training without additional protein supplementation.

这些人原本每天摄入约每公斤体重1.2克蛋白质。

So these people were getting around 1.2 grams of protein per kilogram body weight.

因此，在结合抗阻训练的情况下，调整蛋白质摄入量对肌肉质量和力量都至关重要。

So dialing in that protein intake matters for both muscle mass and strength when combined with the resistance training.

骨骼肌约占我们瘦体重的30%至40%。

Skeletal muscle makes up around 30 to 40% of our lean body mass.

更多肌肉不仅仅意味着更强的力量。

More muscle doesn't just mean more strength.

它还意味着更好的新陈代谢、增强的胰岛素敏感性，以及对二型糖尿病的良好防御。

It means better metabolism, enhanced insulin sensitivity, and a pretty good defense against type two diabetes.

它还能显著降低虚弱和肌肉减少症的风险，这是老年人跌倒和骨折的主要风险因素之一。

It also dramatically decreases frailty and the risk for sarcopenia, one of the main risk factors for falls and fractures in older adults.

研究表明，遭受脆性骨折的人死亡率是未骨折者的两倍。

Research has shown that individuals who suffer from a fragility fracture are twice as likely to die compared to those without such fractures.

而在髋部骨折患者中，22%至58%的人在受伤后仅12个月内就会去世。

And between twenty two to fifty eight percent of people with a hip fracture pass away within just twelve months after the injury.

在老年时期，跌倒并摔断髋骨实际上可能等同于死刑判决。

In old age, falling and breaking a hip can literally be a death sentence.

更好的身体组成能显著提高生活质量并降低残疾风险。

A better body composition dramatically improves quality of life and reduces disability risk.

较高的肌肉量可使早逝风险降低30%，而高脂肪量则会使该风险增加56%。

Having a higher muscle mass can decrease the risk of early death by thirty percent, whereas having a high fat mass can increase that risk by fifty six percent.

那么，为什么随着年龄增长，我们更容易流失肌肉质量呢？

So what explains our greater susceptibility to lose muscle mass as we get older?

有几个因素在其中起作用，但一个主要原因是所谓的合成代谢抵抗现象。

There are a few factors that play a role in this, but a big player here is a phenomenon called anabolic resistance.

随着年龄增长，我们的肌肉对氨基酸的反应会减弱，这意味着它们无法像年轻时那样有效地通过蛋白质摄入来触发肌肉蛋白质合成。

So as we age, our muscles become less responsive to amino acids, meaning they don't trigger muscle protein synthesis in response to protein intake as effectively.

因此对老年人来说，相同量的蛋白质摄入导致的肌肉蛋白质合成增加幅度比年轻人要小。

So for older individuals, the same amount of protein results in a smaller increase in muscle protein synthesis compared to younger people.

一些研究表明，老年人需要几乎两倍的蛋白质才能产生相同的反应。

Some studies have shown that an older person requires almost twice as much protein for the same response.

例如，大约每公斤体重0.24克蛋白质或每磅0.1克。

For example, around zero point two four grams of protein per kilogram body weight or 0.1 per pound.

对于一个80公斤的年轻人来说，20克蛋白质就能最大程度地刺激肌肉蛋白质合成。

That's 20 grams of protein for about an eighty kilogram man, maximally stimulates muscle protein synthesis in someone young.

但这个剂量对老年人来说需要更高，他们每公斤需要约0.4克蛋白质，或每磅体重每次摄入0.18克蛋白质。

But this dose is higher for older adults who need about 0.4 of protein per kilogram or zero point one eight grams per pound of protein per dose.

一位体重约80公斤的老年男性需要约32克蛋白质才能最大程度刺激肌肉蛋白质合成。

An older adult man weighing about eighty kilograms would need about 32 grams of protein to maximally stimulate muscle protein synthesis.

顺便提一下，对于做笔记的人来说，这表明每剂蛋白质的最佳摄入量在20克至高达35克之间，具体取决于个人的合成代谢抵抗水平。

By the way, for anyone taking notes, this suggests that the optimal amount of protein per dose is between 20 and as high as 35 of protein, depending on your personal level of anabolic resistance.

这意味着以下几点。

So this means a few things.

首先，如果你年纪较大，你需要更高的每日蛋白质总摄入量来维持或增加肌肉量。

The first is that if you're older, you need a higher total daily protein intake to maintain or increase muscle mass.

这也意味着每餐需要摄入更高剂量的蛋白质来刺激肌肉蛋白质合成。

It also means that you need a higher dose of protein at each meal to stimulate muscle protein synthesis.

但合成代谢抵抗并非不可避免，也不仅仅像某些人认为的那样是由于衰老导致的。

But anabolic resistance is not inevitable or only due to aging as some might suggest.

事实上，缺乏身体活动可能是最大的影响因素。

In fact, physical inactivity may actually be the biggest contributor.

减少身体活动会加剧合成代谢抵抗。

Reducing physical activity worsens anabolic resistance.

例如，老年人仅需减少步数两周就会导致合成代谢抵抗并降低胰岛素敏感性。

For example, taking fewer steps for just two weeks causes anabolic resistance in older adults and reduces their insulin sensitivity.

想象一下数十年的不活动会带来什么后果。

Imagine what decades of inactivity can do.

这是坏消息。

That's the bad news.

但好消息是运动能使肌肉对蛋白质更敏感，基本上抵消了合成代谢抵抗。

But the good news is that exercise makes muscle more sensitive to protein and essentially negates anabolic resistance.

当老年人在摄入蛋白质前进行锻炼时，他们的肌肉合成代谢反应与年轻人完全相同。

When older adults exercise before protein intake, their muscle anabolic response is identical to that of a younger adult.

那么我该如何理解这一点？

So how do I interpret this?

活跃的老年人可能不会像不活跃人群那样经历严重的合成代谢抵抗，因此对经常运动的人来说这可能不是大问题。

Active older adults probably don't experience as much anabolic resistance as inactive people, and therefore, it might not be such an issue for people that are physically active.

随着年龄增长，对抗合成代谢抵抗最有效的方法是通过定期体育锻炼结合更高的每日蛋白质摄入量，理想情况下约为每公斤体重1.6克。

The most effective way to combat anabolic resistance as we age is through regular physical activity combined with a higher daily protein intake, ideally around 1.6 grams per kilogram body weight.

我们不必在老年时变得虚弱。

We do not have to be frail in old age.

我们可以在四十岁、五十岁、六十岁甚至七十岁及以后增肌，而且在这个年龄段我们绝对可以提高肌肉力量和功率输出。

We can build muscle into our forties, fifties, sixties, and even our seventies and beyond, and we can definitely increase muscle strength and power output at this age.

一项招募90岁及以上成年人的研究中，八周高强度力量训练使肌肉力量增加了174%，即使在人生第九个十年——这个大多数人根本不会考虑举重的年龄——肌肉力量和体积也能增长。

In one study that recruited adults aged 90 years and older, eight weeks of high intensity strength training produced a 174% increase in muscle strength, muscle strength and size increased even in the ninth decade of life, an age when most people wouldn't even think twice about touching a weight.

那么让我们来谈谈最佳蛋白质摄入量。

So let's talk about the optimal protein intake.

最佳蛋白质摄入量因人而异。

The optimal amount of protein will not be the same for everyone.

有些人想要增加肌肉量，有些人想要维持肌肉量，还有些人希望通过增肌减脂来改善身体成分。

Some people want to build muscle mass, some people want to maintain it, and others want to improve their body composition by building muscle and losing fat.

每个目标都需要更有针对性的方法。

Each of these goals requires a more tailored approach.

首先要了解的是，人们普遍认为蛋白质需求应基于瘦体重或调整后的体重来计算，这反映了健康的体脂百分比。

The first thing to know is that it's generally agreed upon that protein needs should be calculated based on a lean body mass or an adjusted body weight, reflecting a healthy body fat percentage.

例如，男性12%到15%，女性约20%的体脂率。

So for example, 12 to 15% for men and around 20% for women.

这样可以避免设定不切实际的目标，特别是对超重或肥胖人群而言。

This prevents unrealistic targets, especially for those who are overweight or obese.

因此当我提到每日每公斤体重蛋白质摄入量时，理想情况下指的是你的理想或目标体重。

So when I refer to protein intake in grams per kilogram of body weight per day, what I'm ideally referring to is your ideal or goal body weight.

让我们先明确一点。

Let's address one thing upfront.

许多人认为每日每公斤体重0.8克的蛋白质推荐膳食摄入量（RDA）标准过低。

The recommended dietary allowance or the RDA for protein of 0.8 per kilogram per day is thought by many to be too low.

这是因为RDA源自氮平衡研究，而该研究由于收集不完整和氨基酸流失估算不准确存在局限性。

This is because the RDA was derived from nitrogen balance studies, which have limitations due to incomplete collection and inaccurate estimates of amino acid losses.

每日蛋白质最佳摄入范围更接近每公斤体重1.2至1.6克，或约每磅0.54至0.72克。

The optimal range for daily protein intake is closer to 1.2 to 1.6 grams per kilogram body weight per day or roughly 0.54 to 0.72 grams per pound.

这是基于稳定同位素研究等替代方法得出的结论，这些研究一致表明要维持正蛋白质平衡，所需摄入量远高于常被引用的每公斤0.8克标准。

This is based on alternative methods like stable isotope studies, which consistently show that higher intakes are necessary to maintain a positive protein balance far above the 0.8 grams per kilogram often cited.

因此，我们讨论的最佳蛋白质摄入量是至少1.2克至1.6克。

So aiming for at least 1.2 grams and up to 1.6 grams is what we're talking about for optimal protein intake.

有充分证据支持这一观点。

There's good evidence to suggest this.

例如，与每日摄入0.8克/公斤体重的RDA标准相比，每日摄入至少1.2克/公斤体重的老年人能有效预防与年龄相关的肌肉流失。

For example, older adults consuming at least 1.2 grams of protein per kilogram body weight per day prevented age related losses in lean mass when compared to consuming the RDA of 0.8 grams per kilogram body weight.

老年女性在摄入高于RDA标准的蛋白质时，出现身体虚弱的概率也降低了30%。

Older women were also 30% less likely to experience frailty when consuming protein above the RDA.

那么在进行抗阻训练时，增肌的最佳蛋白质摄入量是多少？

So what is the optimal protein intake for building muscle while resistance training?

研究表明，进行抗阻训练的人群每日摄入1.6克/公斤体重的蛋白质，可使瘦体重增长最大化——相比1.2克/公斤的摄入量，肌肉量能增加27%。

For people engaged in resistance training, a protein intake of 1.6 grams per kilogram body weight per day has been shown to maximize gains in lean body mass with a 27% increase in muscle mass over even a 1.2 gram per kilogram intake.

这个数字相当可观，它充分说明了0.8克/公斤体重的RDA标准是多么不足。

That's a lot, and it really just serves to really underscore how low the RDA really is when you're talking about 0.8 grams per kilogram body weight.

顺便说一句，关于蛋白质RDA标准更深入的讨论，可以参考我对博士的访谈。

By the way, for an excellent discussion of the protein RDA and much more, see my interview with Doctor.

Stuart Phillips博士在第76期Found My Fitness播客中的访谈。

Stuart Phillips in episode 76 of the Found My Fitness Podcast.

在某些特殊情况下，更高的蛋白质摄入量可能会带来一些边际效益。

There are special circumstances where even a higher protein intake might offer some marginal benefit.

第一个例子是正在进行身体重组的人群，他们处于能量赤字状态以减少脂肪量，同时保持甚至增加肌肉量。

The first example is people undergoing body recomposition, where they are in an energy deficit to lose fat mass while preserving or even increasing muscle mass.

让我们再详细讨论一下身体重组和减重。

So let's talk a little bit more about body recomposition and weight loss.

较高的蛋白质摄入量通常能增强饱腹感。

A higher protein intake tends to improve satiety.

它能帮助你更长时间保持饱腹感，并可能有助于防止暴饮暴食。

It helps you feel fuller for longer and may help prevent overeating.

对于想要减重的人来说，这是一个主要优势。

For people who want to lose weight, this is a major benefit.

在减重期间增加蛋白质摄入对于防止瘦体重的流失也至关重要。

Eating more protein is also essential during weight loss to prevent the loss of lean body mass.

当你采用高蛋白限制热量饮食时，减掉的体重更多来自脂肪而非肌肉。

When you eat a higher protein calorie restricted diet, more weight loss comes from fat mass than muscle mass.

但请记住，抗阻训练对于防止瘦体重流失同样重要。

But remember, resistance training is also important to prevent the loss of lean mass.

高蛋白饮食还可能因食物热效应略微提高代谢率，帮助你在一天中多燃烧一些卡路里。

High protein diets may also cause a slight increase in the metabolic rate due to the thermic effect of food, helping you burn a few more calories throughout the day.

第二个例子是专业运动员，当蛋白质摄入量超过每公斤1.6克时可能有益，因为肌肉蛋白质合成的极微小改善能带来竞争优势。

The second example where a higher protein intake above 1.6 grams per kilogram may be beneficial is with professional athletes where extremely marginal improvements in muscle protein synthesis gives them an edge on competition.

因此在这种情况下，每天每公斤2.2克蛋白质或每磅1克蛋白质可能带来边际效益。

So in this scenario, this is where up to 2.2 grams of protein per kilogram per day or one gram per pound may provide marginal benefits.

尽管存在普遍误解，对于没有肾脏疾病的人而言，极高蛋白摄入并不会损害肾脏健康。

Despite common misconceptions, a very high protein intake is not harmful to kidney health in people without preexisting kidney conditions.

研究一致表明高蛋白饮食对大多数人是安全的，关于肾脏损伤的担忧基本没有依据。

Research consistently shows that high protein diets are safe for most people, and any concerns over kidney damage are largely unfounded.

那么我们来谈谈这个误区。

So let's talk about this myth.

早期对某些研究的解读认为，过量蛋白质摄入可能会使肾脏过度工作。

Early interpretations of certain studies suggested that excessive protein intake might overwork the kidneys.

虽然蛋白质限制可以延缓某些个体肾脏疾病的进展，但我们现已明确这并不意味着健康人群应该限制蛋白质摄入。

While protein restriction can slow the progression of kidney disease in some individuals, we now know this does not imply that a healthy people should limit their protein consumption.

高蛋白饮食确实会引起肾功能的变化，但不会造成肾脏负担过重。

Higher protein diets do induce changes in kidney function, but they do not overburden the kidneys.

观察到的肾功能指标上升是机体为清除蛋白质代谢产生的尿素等废物而做出的正常适应性反应。

The observed increase in markers in kidney function is a normal adaptive response to eliminate urea and other waste products generated during protein metabolism.

这对于肾功能健康的人群来说完全正常。

This is entirely normal for individuals with healthy renal function.

因此现有证据并不支持高蛋白摄入与健康成年人或高危人群（如肥胖、高血压甚至糖尿病患者）肾脏疾病之间存在关联。

So current evidence does not support an association between higher protein intake and kidney disease among healthy adults or those at risk, such as individuals with obesity, hypertension, or even diabetes.

此外，对运动员的研究表明，每天摄入高达3.2至4.5克/公斤体重的蛋白质持续一年，不会引起肾功能的不良变化，且被认为是安全的。

Moreover, research in athletes has shown that consuming protein intakes as high as 3.2 to 4.5 grams per kilogram of body weight per day for up to one year does not cause any adverse changes in kidney function and is considered safe.

这个摄入量是蛋白质推荐每日摄入量的4到6倍。

This intake is four to six times higher than the RDA for protein.

最新研究甚至表明，较高的蛋白质摄入量可能对慢性肾病患者有益。

And emerging research even suggests that higher protein intake may actually be beneficial for people with chronic kidney disease.

一些研究发现，摄入高于推荐膳食摄入量的蛋白质与这一人群的死亡风险降低相关，这挑战了传统的蛋白质限制方法。

Some studies have found that consuming protein at levels above the RDA is associated with reduced mortality risk in this population, challenging the traditional approach of protein restriction.

归根结底，我们可以彻底摒弃高蛋白饮食损害健康肾脏的谬论了。

The bottom line, can finally put to rest the myth that high protein diets harm healthy kidneys.

现在该探讨蛋白质摄入的另一个重要方面了，即我们应多久摄入一次以及何时摄入。

It's time to tackle another important aspect of protein intake, and that's how often and when we should consume it.

我们将讨论两个关键点。

We'll tackle two key points.

首先，我们如何分配每日蛋白质摄入量——是均匀分布在三到四餐中，还是集中在一两餐中摄入。

First, how we consume our daily protein intake, whether we should spread it evenly across three to four meals or load it up into one or two meals.

其次相关的问题是，蛋白质是否必须在关键的合成代谢窗口期摄入，或需要与训练时间同步？

Second and related, does protein have to be consumed within a critical anabolic window or timed with our workouts?

简而言之，这两个问题的答案都是：这些因素的整体重要性可能比你想象的要低。

In short, the answer to both of these is that factors are less important overall than you might expect.

最新证据表明，人体能有效利用甚至极大剂量的蛋白质摄入。

Emerging evidence reveals that the body can effectively utilize even very large protein doses.

这挑战了蛋白质必须精细分配到多餐中以最大化肌肉蛋白质合成的传统观念。

This challenges the notion that protein must be meticulously spread over multiple meals to maximize muscle protein synthesis.

虽然每日蛋白质均匀分布最为理想，但这并不意味着将相同总量的蛋白质集中在少数高蛋白餐中会效果不佳。

Even though an even daily protein distribution is ideal, this doesn't mean that consuming the same total amount of protein in fewer high protein meals is ineffective.

蛋白质分配很重要，但并非至关重要。

Protein distribution is important, but not vital.

当你摄入较大剂量蛋白质时，消化时间会延长，但身体最终会将其充分利用。

When you eat a larger dose of protein, it takes longer to digest, but your body will eventually use it.

这与某些人认为单次摄入超过20-25克蛋白质时会发生的情况截然相反。

This is contrary to what some people think happens when you consume more than 20 to 25 grams of protein in a single meal.

他们认为多余的蛋白质只会被身体排出造成浪费。

They think that the excess protein will just be excreted by the body and otherwise wasted.

事实上，由博士主导的一项研究表明...

In fact, a study by Doctor.

Luke Van Loon及其同事研究发现，运动后摄入100克蛋白质比25克蛋白质能引发更强烈且持久的合成代谢反应，但对氨基酸氧化的影响微乎其微。

Luke Van Loon and colleagues found that consuming 100 grams of protein after exercise led to a more robust and prolonged anabolic response than did 25 grams of protein, but had negligible effects on amino acid oxidation.

该研究的结论是：'人体对蛋白质的合成代谢反应的强度和持续时间没有上限，这一潜力被严重低估了'。

The conclusion from this study was, quote, the magnitude duration of the anabolic response to protein has no upper limit in humans and has been severely underestimated, end quote.

这打破了关于人体一次只能利用20-25克蛋白质的若干迷思。

This dispels a few myths about how the body can use only 20 to 25 grams of protein at once.

从实践角度来看，我们或许应该追求更均匀的每日蛋白质摄入分布模式。

As a practical takeaway, a more evenly distributed pattern of protein intake throughout the day is probably what we should be striving for.

但此类证据表明，越来越多专家正达成共识：无论是否运动员，大多数人都应从每日总摄入量的角度考虑蛋白质摄入，而非过度关注进食时机或单餐摄入量。

But evidence like this highlights why more and more experts seem to be aligning on the simple fact that the vast majority of us, athletes or not, should be thinking about protein intake from the standpoint of total daily intake with less overall focus on factors like timing or the per meal intake.

关于蛋白质摄入时机的另一个常见疑问是：是否需要运动后立即补充蛋白质以增强训练效果。

Another question that people have regarding protein timing is whether protein needs to be consumed immediately after exercise to enhance the effects of training.

这一概念被称为合成代谢窗口。

This idea is known as the anabolic window.

合成代谢窗口是指运动后约30分钟至2小时的时段，此时身体处于最佳营养吸收状态，能高效利用蛋白质和碳水化合物进行肌肉修复与生长。

The anabolic window is a period after exercise, typically lasting from thirty minutes to two hours, during which the body is primed to absorb and utilize nutrients, particularly protein and carbohydrates, for muscle repair and growth.

这是因为身体合成蛋白质和补充糖原储备的能力在运动后增强，得益于运动引起的激素变化，如胰岛素水平升高。

It occurs because the body's ability to synthesize protein and replenish glycogen stores is heightened, aided by exercise induced hormonal changes like increased insulin levels.

在合成代谢窗口期摄入20至40克优质蛋白质（通常搭配碳水化合物）可以促进肌肉恢复和生长——至少过去是这么认为的。

Consuming 20 to 40 grams of high quality protein often paired with carbohydrates can enhance muscle recovery and growth during the anabolic window, or so it was once thought.

最新科学证据表明，运动后肌肉蛋白质合成显著提升的状态可持续整整24小时，这彻底推翻了合成代谢窗口期仅持续几小时的传统观点。

Recent scientific evidence reveals that muscle protein synthesis remains significantly elevated for a full twenty four hours following exercise, effectively debunking the notion of a very narrow anabolic window lasting only a few hours.

此外，运动前补充蛋白质对身体成分和力量的影响与运动后立即补充蛋白质的效果相同。

Furthermore, supplementing with protein before exercise has the same effects on body composition and strength compared to supplementing with protein immediately after exercise.

换句话说，运动前后摄入蛋白质并没有实质性差异。

In other words, there are no meaningful differences between pre and post exercise protein ingestion.

这意味着只要每日蛋白质总摄入量足够支持最佳蛋白质合成，你可以自由选择在运动前后任何时间补充蛋白质。

This means that you're free to choose when you want to consume protein in relation to exercise so long as your total daily intake of protein is adequately high to support optimal protein synthesis.

当然，运动后立即补充蛋白质肯定没有坏处，特别是对于那些追求力量或肌肉量边际增益的人群。

Of course, there is definitely no downside to consuming protein immediately after a workout, especially for people interested in achieving marginal gains in strength or muscle mass.

最后关于蛋白质摄入时机的话题，我想再提出一个与蛋白质分配和时间相关的增肌策略——睡前蛋白质补充。

To wrap up our discussion on protein timing and distribution, I want to bring up one more strategy to help with muscle building that relates to protein distribution and timing, presleep protein.

这个问题可以从两个角度来看。

There's two ways to look at this.

一种是通过限时饮食的视角，另一种是通过在训练日主动优化肌肉蛋白质合成的视角。

One way is through the lens of time restricted eating, and the other is through the lens of actively optimizing for muscle protein synthesis on training days.

Luke Van Loon博士及其团队的研究表明，

It's been shown in studies by Doctor.

睡前摄入的蛋白质会在夜间被消化吸收。

Luke Van Loon and colleagues that protein consumed before bed is digested and absorbed overnight.

它还能提高夜间肌肉蛋白质合成率，并改善当天早些时候进行抗阻训练人群的净蛋白质平衡，从而促进肌肉恢复。

It also increases overnight muscle protein synthesis rates and improves net protein balance in people who had performed resistance training earlier in the day to enhance muscle recovery.

睡前蛋白质的益处也在长期抗阻训练期间得到了验证。

The benefits of pre sleep protein have also been shown during chronic resistance exercise training.

在抗阻训练期间每晚睡前摄入约30克蛋白质，似乎能增加肌肉量和肌肉力量。

Consuming about 30 grams of protein before bed every night while resistance training appears to increase muscle mass and muscle strength.

关于睡前蛋白质的另一点是，它似乎不会降低食欲或减弱次日早餐时的肌肉蛋白质合成反应——这可能是某些人担心的问题。

Another thing about presleep protein is that it does not seem to reduce appetite or diminish the muscle protein synthesis response at breakfast the next morning, which may have been a concern for some people.

总的来说，我认为睡前蛋白质只是增加每日总蛋白质摄入量的一种方式。

Overall, I think presleep protein is just one way to increase total daily protein intake.

如果你不喜欢饿着肚子睡觉，在训练日喝一杯低热量的蛋白质奶昔可能有助于增强你在那些训练日的肌肉增长。

If you don't like going to bed hungry, having a low calorie protein shake on training days may have the benefit of potentially enhancing your muscle gain on those training days.

但不要以此为借口放纵自己。

But don't use this as an excuse to go wild.

我们仍应注意接近习惯就寝时间时胰岛素敏感性的下降。

We should still be mindful about the fall in insulin sensitivity that happens as we get close to our habitual bedtime.

如果你没有积极训练，这一点尤其重要。

And this is particularly true if you're not actively training.

那么让我们总结一些关于蛋白质摄入时机和分配的关键点。

So let's summarize some key points about protein timing and distribution.

首先，虽然不一定要在锻炼后立即摄入蛋白质，但这样做也无妨。

First, while it's not necessary to consume protein immediately after a workout, there's no harm in doing so.

对于那些空腹锻炼的人来说，之后立即吃一顿富含蛋白质的餐食可能是有益的。

For those who exercise fasted, having a protein rich meal right after may be beneficial.

归根结底，每日蛋白质总摄入量才是最关键的要素。

Ultimately, total daily protein intake is the most crucial factor.

其次，虽然均匀分配各餐蛋白质最为理想，但人体也能有效利用大剂量蛋白质餐。

Second, evenly distributing protein across meals is ideal, but your body can use even large protein meals.

最后，睡前摄入蛋白质并非必需，但可以作为增加每日总摄入量或促进肌肉恢复的有效策略，尤其对积极训练的人群而言。

And finally, consuming protein before bed isn't essential, but it can be a helpful strategy to boost total daily intake or support muscle recovery, especially in those who are actively training.

如果不讨论最佳蛋白质来源，特别是关于促进肌肉蛋白质合成的部分，所有这些蛋白质话题都缺乏实际意义。

All this talk about protein lacks context unless we discuss the best sources of protein, particularly when it comes to stimulating muscle protein synthesis.

动物蛋白比植物蛋白更好吗？

Is animal protein better than plant protein?

那么乳清蛋白与酪蛋白相比又如何呢？

What about whey protein compared to casein protein?

优质蛋白质能被高效消化利用，从而最大化肌肉蛋白质合成。

A high quality protein can be efficiently digested and utilized to maximize muscle protein synthesis.

影响蛋白质消化率的因素包括：是否为完整食物来源、动物性或植物性蛋白质来源、其他营养素（如主要存在于植物性食物中的纤维）的存在，以及蛋白质的氨基酸组成。

Several factors influence a protein's digestibility, including whether it's a whole food source, an animal based or plant based protein source, the presence of other nutrients like fiber, which are mainly present in plant foods, and the amino acid composition of the protein.

就氨基酸组成而言，亮氨酸对蛋白质质量尤为重要。

When it comes to the amino acid composition, leucine is of particular importance for protein quality.

蛋白质的主要合成代谢成分是支链氨基酸亮氨酸，它是肌肉蛋白质合成的强力刺激物。

The main anabolic component of protein is the branched chain amino acid leucine, which is a potent stimulator of muscle protein synthesis.

亮氨酸通过激活mTOR通路来刺激肌肉蛋白质合成，该通路是我们体内细胞生长和代谢的核心调节器。

Leucine stimulates muscle protein synthesis by activating the mTOR pathway, which is our body's central regulator of cell growth and metabolism.

事实上，在决定肌肉蛋白质合成代谢反应时，亮氨酸似乎比食物或补充剂中的总蛋白质含量更为关键。

In fact, leucine appears to be more critical than the total protein content of food or supplement in determining the muscle protein anabolic response.

这一概念被称为亮氨酸阈值或亮氨酸触发假说，它表明必须摄入特定量的亮氨酸才能激活肌肉蛋白质合成。

This concept is referred to as the leucine threshold or the leucine trigger hypothesis, which suggests that a specific amount of leucine must be consumed to activate muscle protein synthesis.

本质上，亮氨酸就像启动肌肉蛋白质构建过程的开关。

Essentially, leucine acts as a switch kickstarting the muscle protein building process.

每公斤体重约0.25克的单餐蛋白质摄入量可提供饱和剂量的亮氨酸和氨基酸，刺激肌肉蛋白质合成长达六小时。

About 0.25 grams of protein per kilogram body weight in a single meal provides a saturating dose of leucine and amino acids to stimulate muscle protein synthesis for up to six hours.

这大约相当于2-3克亮氨酸，可通过摄入20克乳清蛋白等高质量蛋白质来获取。

That's about two to three grams of leucine, which can be obtained by consuming 20 of a high quality protein like whey protein.

尽管亮氨酸可能是刺激肌肉蛋白质合成最重要的氨基酸，但所有氨基酸都是维持肌肉蛋白质合成过程持续4到6小时所必需的。

Even though leucine might be the most important amino acid for stimulating muscle protein synthesis, all of the amino acids are required to allow the process of muscle protein synthesis to sustain for four to six hours.

亮氨酸是信号分子，但我们还需要所有构建肌肉蛋白质所需的原料。

Leucine is the signal, but we also need to have all of the building blocks to build and repair muscle protein.

运动能降低亮氨酸阈值，因为它使肌肉对氨基酸更敏感。

Exercise lowers that leucine threshold because it makes muscle more sensitive to amino acids.

这意味着运动后需要更少的亮氨酸剂量，因此需要更少的蛋白质剂量就能达到亮氨酸阈值并刺激肌肉蛋白质合成。

This means a lower dose of leucine, and therefore a lower dose of protein is needed to reach the leucine threshold and stimulate muscle protein synthesis after exercise.

衰老确实会降低对亮氨酸和其他氨基酸的敏感性。

Aging does reduce the sensitivity of leucine and other amino acids.

与年轻人相比，老年人需要更大剂量的蛋白质或亮氨酸才能刺激相同的肌肉蛋白质合成反应。

It takes a larger dose of protein or leucine to stimulate the same muscle protein synthesis response for someone who is older compared to a younger adult.

但经常锻炼的老年人可以帮助克服这个问题，因为运动能提高对亮氨酸的敏感性。

But again, older adults who routinely exercise can help overcome this since exercise increases sensitivity to leucine.

如果你摄入多种植物性和动物性食物来源，和/或补充乳清蛋白，你可能不需要担心每餐或全天摄入足够的亮氨酸。

If you're consuming a variety of plant based and animal based food sources and or supplementing with whey protein, you probably don't have to worry about consuming enough leucine at each meal or throughout the day.

关注全食物是确保摄入足够亮氨酸的最佳方式。

Focusing on whole foods is the best way to ensure you're getting enough leucine.

当然，如果你有所顾虑，在饮食中添加乳清蛋白或支链氨基酸补充剂是获取额外亮氨酸的另一种方法。

But of course, if you're concerned, adding whey protein or branched chain amino acid supplement to your diet is another way to get additional leucine.

现在让我们来讨论动物性蛋白与植物性蛋白的区别。

Now let's talk about the difference between protein from animal and plant based sources.

动物蛋白 vs 植物蛋白。

Animal versus plant protein.

无论你更倾向于植物性饮食还是包含肉类的饮食，仅从优化肌肉蛋白质合成的角度来看，动物来源的蛋白质更胜一筹。

Whether your loyalties are towards a plant based diet or a meat inclusive diet from a standpoint of just focusing on optimizing for muscle protein synthesis, an animal sourced protein is better.

对大多数人来说，从动物性食物中获取蛋白质也更为容易，原因有几个。

It is also easier for most people to obtain protein from an animal based food source for a few reason.

首先，动物蛋白来源具有更高的蛋白质密度。

For one, animal protein sources have a greater protein density.

植物性食物每克所含的蛋白质通常比大多数动物性食物要少。

Plant based foods contain less protein per gram than most animal based foods.

例如，要从土豆中获取20克蛋白质，你需要食用超过一公斤的土豆，而仅需70克鸡肉或牛肉就能提供20克蛋白质。

For example, getting 20 grams of protein from potatoes means you need to consume more than a kilogram of potatoes, but just 70 grams of meat like chicken or beef contain 20 grams of protein.

其次，植物性食物的消化率低于动物性食物，这主要是由于植物中含有由纤维构成的食物基质。

Second, plant based foods have a lower digestibility than animal based foods, largely due to the presence of a food matrix consisting of fiber.

纤维会略微降低人体提取和利用植物蛋白质的能力。

Fiber can slightly reduce the body's ability to extract and utilize protein found in plants.

它还会减缓消化过程。

It also slows the digestion process.

发芽和发酵可以部分克服这一问题，提高植物蛋白的消化率和吸收率。

Sprouting and fermenting can overcome some of this and improve the digestibility and absorption of plant protein.

第三，植物蛋白往往缺乏一种或多种必需氨基酸。

Third, plant proteins are often deficient in one or more of the essential amino acids.

例如赖氨酸、蛋氨酸，最重要的是亮氨酸。

For example, lysine, methionine, and most importantly, leucine.

记住，必需氨基酸需要通过饮食摄入，才能在体内构建完整的蛋白质。

Remember that essential amino acids are needed to be consumed in the diet to build complete proteins in the body.

必需氨基酸含量较低意味着大多数植物蛋白都是不完全蛋白，与动物蛋白相比，它们刺激的合成代谢反应较弱。

A lower essential amino acid content means that most plant proteins are incomplete proteins and stimulate a lower anabolic response compared to animal based protein.

如果你选择植物性饮食，确实还有其他选择。

If you're eating plant based, you do have options.

通过补充植物蛋白分离物和浓缩物、每天摄入更多蛋白质以弥补蛋白质质量较低的问题，以及多样化摄入各种植物蛋白来源来形成具有正确氨基酸谱的互补蛋白，可以满足植物性饮食的蛋白质需求。

Protein needs can be met on plant based diets by supplementing with plant based protein isolates and concentrates, by consuming a larger quantity of protein each day to compensate for a lower protein quality, and also by diversifying the intake of a variety of plant based sources of protein, so creating complementary proteins that have the right amino acid profile.

尽管植物蛋白的合成代谢潜力较低，但研究普遍支持这样的观点：只要每日蛋白质总摄入量足够高，素食或纯素饮食在促进每日肌肉蛋白合成及增加肌肉体积和力量方面，与含动物蛋白的饮食效果相当。

Despite the lower anabolic potential of plant based protein sources, studies generally support the idea that as long as the total daily protein intake is high enough, a vegetarian or a vegan diet can support daily muscle protein synthesis and gains in muscle size and strength as much as a diet containing animal based protein.

但由于植物蛋白质量较低，你需要摄入更多食物才能达到每日蛋白质需求。

But because plant protein is lower in quality, you'll have to consume more food overall to reach your daily protein intake.

但全食物并非蛋白质的唯一来源。

But whole foods aren't the only source of protein.

许多人选择通过蛋白质补充剂或蛋白粉获取蛋白质，有充分理由认为这是一种相当明智的做法。

Many people choose to obtain their protein through protein supplements or protein powder, and there's a good reason to think that this is a fairly sensible practice.

乳清蛋白是最受欢迎的蛋白质补充剂之一，部分原因是它是一种极高品质的蛋白质来源。

Whey protein is one of the most popular protein supplements, in part because it's an extremely high quality protein source.

乳清富含必需氨基酸半胱氨酸及支链氨基酸亮氨酸、异亮氨酸和缬氨酸。

Whey is a rich source of the essential amino acids cysteine and the branched chain amino acids leucine, isoleucine, valine.

乳清还含有多种生物活性肽。

Whey also contains several bioactive peptides.

乳清中的亮氨酸含量使其脱颖而出。

The leucine content of whey is what makes it stand out.

乳清中的亮氨酸含量比其他蛋白质来源高出50%至75%。

The leucine content in whey is 50 to 75% higher than other protein sources.

与牛奶蛋白中的另一种成分酪蛋白相比，乳清蛋白消化更快，在休息和运动后能更有效地刺激肌肉蛋白质合成，因此成为许多运动员的首选蛋白质来源。

Compared to the other component of milk protein like casein, whey protein is more rapidly digested and stimulates muscle protein synthesis more effectively at rest and after exercise, making it a go to protein source for many athletes.

酪蛋白比乳清消化慢并不一定是缺点，因为这意味着酪蛋白能持续释放氨基酸，有助于延长肌肉蛋白质合成反应的时间。

The slower digestion of casein compared to whey isn't necessarily a downside because this means casein provides a prolonged release of amino acids that can be helpful for sustaining the muscle protein synthesis response for a longer period of time.

乳清蛋白和酪蛋白都是比胶原蛋白质量高得多的蛋白质来源，后者的氨基酸组成质量较低。

Whey and casein protein are both much higher quality protein sources than collagen, which has a lower quality amino acid profile.

胶原蛋白富含甘氨酸和脯氨酸，但缺乏亮氨酸等必需氨基酸。

It's rich in glycine and proline, but lacks essential amino acids like leucine.

此外，胶原蛋白在休息或运动后都不会显著促进肌肉蛋白质合成或肌肉结缔组织蛋白质合成，这使得它对于从事抗阻训练并希望改善骨骼肌蛋白质合成的人来说并非最佳蛋白质选择。

Furthermore, collagen does not significantly enhance muscle protein synthesis or muscle connective protein synthesis at rest or after exercise, making it a suboptimal protein choice for those engaged in resistance training and wanting to improve skeletal muscle protein synthesis.

从我们目前的讨论中应该清楚看出，膳食蛋白质——特别是当根据个人目标和需求进行优化时——对几乎所有人都有诸多健康益处。

It should be clear from our discussion thus far that dietary protein, especially when optimized to suit your individual goals and needs, has an array of health benefits for nearly everyone.

它具有提升运动表现、从预防衰弱角度抗衰老的作用，还能帮助减重。

It's performance enhancing, anti aging from the standpoint of frailty prevention, and can help you lose weight.

然而这可能让许多人感到意外，但在老年医学界有一种观点认为过量膳食蛋白质会增加癌症风险并加速衰老。

However, this might come as a surprise to many, but there is a school of thought within the aging community that too much dietary protein increases cancer risk and contributes to accelerated aging.

但如今许多运动员都采用高蛋白饮食。

Yet today, many athletes consume a high protein diet.

事实上，成为运动员——哪怕是业余爱好者——是我们保持良好衰老状态的最佳方式之一。

And the fact of the matter is being an athlete, even a recreational one, is one of the best things we can do to age well.

这在直觉上和科学上都是显而易见的。

This is both intuitively and scientifically obvious.

我们该如何协调这些事实？

How do we reconcile these facts?

我们开始探讨这个问题。

Let's get into it.

一些研究人员认为，高蛋白摄入，尤其是肉类蛋白，会加速衰老甚至增加患癌和早逝的风险。

Some researchers argue that a high protein intake, especially for meat, accelerates aging and even raises the risk of cancer and early death.

这一观点主要源于实验室研究，这些研究表明限制蛋白质摄入能延长动物寿命，以及观察数据显示高动物蛋白饮食与更高死亡率相关。

This idea stems largely from laboratory studies showing that restricting protein intake extends lifespan in animals and observational data linking high animal protein diets to a higher mortality rate.

支持这一观点的研究发现，中年人群中每日热量20%来自蛋白质的高蛋白饮食者，全因死亡率高出75%，癌症死亡率高出四倍。

Supporting this idea, one study found that middle aged adults consuming high protein diets where 20% of their calories came from protein, were seventy five percent more likely to die from any cause and four times more likely to die from cancer.

这是个相当惊人的统计数据，而动物实验在机制层面也部分证实了这一点。

This is a pretty shocking statistic, and animal evidence corroborates some of this at the mechanistic level.

然而，事情并非如此简单。

However, there is more to this story.

另一项重要研究表明，中年高蛋白饮食者确实显示出更高的死亡率，但仅限于同时存在肥胖、吸烟、酗酒或久坐等不健康生活方式因素的人群。

In another major study, middle aged adults consuming high protein diets did show increased mortality rates, but only if they had other unhealthy lifestyle factors like obesity, smoking, heavy drinking, or being sedentary.

在健康人群中，这种关联就消失了。

Among healthy people, this association disappeared.

那么高动物蛋白饮食真的会带来健康风险，还是更多取决于个人生活中存在哪些不健康的生活方式因素？

So does a high animal protein diet really pose a health risk, or is it more about what unhealthy lifestyle factors exist in someone's life?

这里就变得有趣了。

This is where it gets interesting.

蛋白质，尤其是动物来源的蛋白质，会急剧升高一种名为IGF-1的激素水平。这种激素有助于增肌、支持大脑健康、促进肌肉修复，但高IGF-1水平也存在潜在弊端，比如促进癌前细胞存活并可能使其形成癌症。

Protein, particularly from animal sources, spikes levels of a hormone called IGF-one, which can help build muscle, support brain health, it enhances muscle repair, but high IGF-one levels also come with potential downsides like promoting the survival of precancerous cells and potentially allowing them to form cancer.

大量研究发现IGF-1水平升高与多种癌症风险增加存在关联。

Numerous studies have found an association between elevated IGF-one levels and an increased risk of various cancers.

那么我们是否应该大幅减少蛋白质摄入以降低IGF-1水平？

So should we cut protein drastically to lower IGF-one levels?

未必如此。

Not necessarily.

将IGF-1降得过低可能会带来一系列新的风险。

Lowering IGF-one too much can come with its own set of risks.

例如，显著降低IGF-1水平的热量限制，已被发现与非人灵长类动物的脑组织流失有关联。

For example, calorie restriction, which significantly drops IGF-one, has been linked to brain matter loss in nonhuman primates.

这引发了关于低IGF-1水平是否会在脑健康方面有所取舍的问题。

This raises questions about whether low IGF-one might have trade offs in terms of brain health.

那么，是大幅减少蛋白质摄入以避免这些风险更好，还是存在一个平衡点，让我们既能获得肌肉力量、肌肉修复和认知健康，又能预防癌症？

So is it better to significantly cut protein intake and avoid these risks, or is there a balance to be struck that gives us the best of both worlds, muscle strength, muscle repair, cognitive health, and protection against cancer?

最近由博士

A recent meta analysis by Doctor.

瓦尔特·隆戈及其同事进行的荟萃分析强调了这一观点，显示了IGF-1水平与死亡率之间的U型关系。

Valter Longo and colleagues highlighted this idea showing a U shaped relationship between IGF-one levels and mortality.

无论是极高还是极低的IGF-1水平都与更高的死亡率相关。

Both very high and very low IGF-one were linked to higher death rates.

最佳范围是多少？

What was the optimal range?

实际上大约在120至160纳克每毫升之间。

It was actually around 120 to 160 nanograms per milliliter.

为了达到这一IGF-1的理想水平，研究人员估计每日蛋白质摄入量约为50至80克，这并不算很多蛋白质。

And to reach this IGF-one sweet spot, researchers estimated a daily protein intake of around 50 to 80 grams, which is not very much protein.

更不用说这项研究并未专门针对健康且经常运动的人群。

Not to mention this study did not specifically look at healthy, physically active people.

这是问题的关键所在，因为对运动的强烈反应需要IGF-1的参与。

And that's a critical piece to the puzzle because a strong response to exercise requires IGF-one.

这就引出了一个哲学问题。

So it raises a philosophical question.

这些建议是针对健康活跃人群制定的，还是为长期久坐生活方式的人群量身定做的？

Are these recommendations aimed at healthy, physically active individuals, or are they tailored to people maintaining a largely sedentary lifestyle?

体育活动从根本上改变了IGF-1在体内的行为方式。

Physical activity fundamentally changes how IGF-one behaves in the body.

运动能降低血液中的IGF-1水平，将其重新分配到有益部位，比如肌肉组织——特别是大脑。

Exercise lowers IGF-one in the bloodstream, redirecting it to where it can be beneficial, like the muscle and notably the brain.

这之所以重要是因为：

Here's why that's important.

当你进行运动时——无论是心血管运动、力量训练还是高强度间歇训练——都会刺激肌纤维，并增加肌肉细胞中IGF-1受体的密度。

When you exercise, whether it's cardiovascular exercise or strength training or high intensity interval training, it stimulates muscle fibers and increases IGF-one receptor density in the muscle cells.

这使肌肉组织对IGF-1更为敏感，可能增强其吸收能力。

This makes muscle tissue more sensitive to IGF-one, potentially enhancing its uptake.

虽然这一精确机制仍在研究中，但明确的是运动能提高IGF-1穿过血脑屏障的能力。

While this precise mechanism is still being explored in research, what's clear is that exercise increases the ability of IGF-one to cross the blood brain barrier.

一旦进入大脑，IGF-1在促进神经发生中起着关键作用。

Once in the brain, IGF-one plays a crucial role in promoting neurogenesis.

这就是新脑细胞的生长，尤其在海马体等对学习和记忆至关重要的大脑区域。

That's the growth of new brain cells, especially in regions of the brain like the hippocampus, which is important for learning and memory.

运动的作用不止于此。

Exercise doesn't stop there.

运动，特别是高强度运动，还会提升与IGF-1结合的蛋白质水平，降低其可能形成癌细胞的损伤细胞的生物利用度。

Exercise, particularly intensive exercise, also raises levels of proteins that bind to IGF-one and reduce its bioavailability to damage cells that could potentially form cancer cells.

仅运动本身就会促使更多氨基酸被骨骼肌吸收，这同样具有降低循环IGF-1的效果。

Exercise alone causes more amino acids to be taken up into skeletal muscle, which also has the effect of reducing circulating IGF-one.

事实上，运动后摄入蛋白质时，IGF-1水平不会像未运动直接摄入蛋白质那样在随后24小时内升高。

In fact, when protein is consumed after exercise, IGF-one levels do not increase in the ensuing twenty four hours like they do when protein is eaten without exercising beforehand.

因此，通过调控IGF-1的利用方式并减少其可能刺激癌细胞的可用性，运动起到了保护屏障的作用。

So by channeling how IGF-one is used and making it less available to potentially stimulate cancer cells, exercise acts as a protective shield.

长期研究表明，规律运动能显著降低多种癌症风险，而这可能正是解释这一现象的关键机制之一。

Regular physical activity has long been shown to strongly reduce the risk of many types of cancer, And this may just be one crucial mechanism that accounts for that fact.

此外，运动能增强免疫系统发现并摧毁癌细胞的能力。

Furthermore, exercise enhances the immune system's ability to find and destroy cancer cells.

它能降低慢性炎症（已知的癌症风险因素），并改善胰岛素敏感性，从而进一步影响IGF-1水平。

It lowers chronic inflammation, which is a known risk factor for cancer, and it improves insulin sensitivity, which can further influence IGF-one levels.

简而言之，较高的IGF-1水平本身并不危险。

So in short, higher IGF-one levels aren't inherently dangerous.

关键在于具体情境。

It's the context that matters.

运动和健康的生活方式完全改变了这个叙事，向我们证明：在积极平衡的生活方式引导下，IGF-1可以成为健康、力量和长寿的强大盟友。

Exercise and a healthy lifestyle change the story entirely, showing us that IGF-one can be a powerful ally for health, strength, and also longevity when guided by an active, balanced lifestyle.

这引出了另一个重要问题。

This brings us to another important question.

如果蛋白质本质上确实会促进衰老，那么我们是否应该预期高蛋白摄入人群（例如运动员）的预期寿命会缩短？

If protein truly is inherently pro aging, wouldn't we expect a population with a higher protein intake, athletes, for example, to experience reduced life expectancy?

但事实似乎并非如此，实际上恰恰相反。

But this doesn't appear to be the case, and in fact, the opposite is true.

我们合理推测通常摄入更多蛋白质的运动员，其IGF-1水平持续较高，但数据显示他们普遍寿命更长且健康指标更优。

Athletes who we can reasonably expect generally consume higher protein amounts and are known to have elevated IGF-one levels consistently show longer lifespans and a better health metric.

平均而言，他们比普通人群多活2到8年。

On average, they live two to eight years longer than the general population.

他们死于癌症和心血管疾病的概率也更低。

They also die less of cancer and cardiovascular diseases.

让我们回到氨基酸亮氨酸这个话题。

Let's circle back to the amino acid leucine.

无论是讨论优化肌肉蛋白质合成，还是关于IGF-1和mTOR在衰老领域的争议，亮氨酸都是核心所在。

Whether we're talking about optimizing muscle protein synthesis or controversies in the aging field surrounding IGF-one and mTOR, leucine is at the heart of it.

亮氨酸是强力激活mTOR的关键信号分子。

Leucine is the critical signal driving robust activation of mTOR.

动物蛋白含有大量亮氨酸，而你是否认为这是好事，实际上取决于你对IGF-1和mTOR的看法。

Animal protein has a lot of leucine, and whether you consider that a good thing or not actually depends on your views of IGF-one and mTOR.

mTOR通过驱动肌肉蛋白质合成和恢复，在骨骼肌生长中发挥关键作用。

MTOR plays key roles in skeletal muscle growth by driving muscle protein synthesis and recovery.

但这将我们引向mTOR通路引发争议的另一个领域——它与动脉粥样硬化的潜在关联。

But this brings us to another area where mTOR pathway has also sparked controversy, its potential connection to atherosclerosis.

2024年初的一项研究表明，高蛋白摄入可能加速动脉粥样硬化的发展，即动脉硬化和僵化。

A study from early twenty twenty four suggested that a high protein intake could accelerate the development of atherosclerosis, which is the hardening and stiffening of arteries.

该研究指出，激活肌肉组织中mTOR以促进肌肉生长的亮氨酸，可能也会激活血管系统中的mTOR，通过免疫细胞激活促进斑块形成。

The study suggested that leucine, which activates mTOR in muscle tissue to drive muscle growth, might also activate mTOR in the vascular system, promoting plaque buildup through immune cell activation.

关键要记住：运动会使亮氨酸被肌肉吸收，在那里激活mTOR以构建和修复肌肉，而非在血液中停留触发血管系统的mTOR。

The important thing to remember is that exercise causes leucine to be taken up by muscle where it activates mTOR in muscle to build and repair muscle rather than spending time in the bloodstream triggering mTOR in the vascular system.

这再次证明，积极运动与久坐不动的生理效应截然不同。

This is yet another example of how being physically active versus sedentary changes the entire equation.

对于经常锻炼的人来说，这完全是另一回事。

It's a different game for people who exercise regularly.

好的。

Okay.

所以，我希望现在大家已经清楚，那些认为高蛋白饮食对健康有害的证据并不特别有力。

So I hope it's clear by now that the evidence suggesting high protein diets are harmful to health is not particularly strong.

关于一些观察性数据暗示高蛋白摄入与癌症等风险之间可能存在联系，这种风险主要适用于久坐不动且伴有其他不健康生活方式因素（如肥胖）的人群。

When it comes to some observational data suggesting a potential link between high protein intake and risks like cancer, this risk primarily applies to sedentary individuals with other unhealthy lifestyle factors like obesity.

对于经常运动的人来说，情况则完全不同。

For physically active people, it's a different story.

运动能确保蛋白质和亮氨酸被导向肌肉生长和修复，使mTOR的激活在肌肉中发挥有益作用，而非外周组织。

Exercise ensures that protein and leucine are directed toward muscle growth and repair, keeping mTOR activation where it's beneficial in the muscles rather than in peripheral tissues.

这解释了为什么运动员尽管摄入更多蛋白质，却比普通人群享有更好的健康和更长的寿命。

This explains why athletes, despite consuming more protein, enjoy better health and longer lifespans than the general population.

关键在于，对活跃人群而言，较高的蛋白质摄入有助于提升表现、延长寿命并促进健康。

The bottom line is that for active individuals, higher protein intake supports performance, longevity, and health.

好了，各位。

All right, everyone.

关于蛋白质科学的讨论就到这里。

That just about does it for our discussion on the science of protein.

总结一下，我想提供八个最重要的要点。

To wrap up, I want to provide eight of the most important takeaways.

第一，大多数成年人每天应摄入每公斤体重1.2至1.6克蛋白质以维持整体健康。

Number one, for most adults, a protein intake in the range of 1.2 to 1.6 grams per kilogram of body weight per day should be consumed to support overall health.

老年人、运动员以及希望在减重同时维持瘦体重的人群，应每天摄入每公斤体重1.6克或更多蛋白质。

Older adults, athletes, and people who want to lose weight while sustaining lean body mass should consume 1.6 grams per kilogram per day or more.

蛋白质需求应根据瘦体重或反映健康体脂率的调整后体重来计算。

Protein needs should be calculated based on lean body mass or an adjusted body weight that reflects a healthy body fat percentage.

男性健康体脂率通常在12%至15%之间，女性约为20%。

This is typically around 12 to 15% for men and 20% for women.

这意味着如果你尚未达到理想体重，应该用你的目标体重来计算蛋白质需求。

This means that if you're not at your ideal weight, you should determine your protein requirements using the target weight you're aiming to achieve.

第二，关于蛋白质摄入时机，运动后所谓的合成代谢窗口期并不像曾经认为的那样短暂。

Number two, when it comes to protein timing, the so called anabolic window after exercise isn't as narrow as once believed.

无论是在锻炼前还是锻炼后摄入蛋白质都有效，但最重要的是关注每日蛋白质总摄入量，这对优化抗阻训练效果至关重要。

Consuming protein either before or after a workout is effective, but also just focusing on total daily protein intake is what is most important for optimizing resistance training gains.

第三点，理想情况下应尽量将蛋白质摄入均匀分配在全天。

Number three, it is ideal to try and distribute your protein intake evenly across the day.

建议每天安排3-4顿富含蛋白质的餐食，每餐包含20-25克优质蛋白质以刺激肌肉蛋白质合成。

Aim for around three to four protein rich meals, each containing around 20 to 25 grams of high quality protein to stimulate muscle protein synthesis.

对于老年人而言，由于他们更高的蛋白质需求和合成代谢抵抗，将每餐蛋白质含量增加到20-30克可能更有益。

For older adults, increasing each meal's protein content to 20 to 30 grams may be advantageous due to their higher protein needs and anabolic resistance.

但请记住，每日蛋白质总摄入量比蛋白质在全天的分配方式重要得多。

But remember that total daily protein intake is much more important than how protein is distributed throughout the day.

第四点，睡前摄入蛋白质（这一做法被称为睡前蛋白质补充）。

Number four, consuming protein before bed, a practice known as presleep protein intake.

这对老年人和运动员尤其有益。

This can be particularly beneficial for older adults and athletes.

这种策略能增强夜间肌肉蛋白质合成并促进肌肉恢复。

This strategy enhances overnight muscle protein synthesis and aids in muscle recovery.