Porque praticar uma alta ingestão de proteínas

[busarello 3354]

Tópico Limpo. 

As discussões sobre macros foram movidas para este topico: 

Espero que a discussão atenha-se ao assunto daqui em diante.

 

[Lucas, o Schrödinger 11489]

Mais um estudo que fala dos benefícios de uma maior ingestão de proteínas. Abaixo abstract:

 

Citar

Protein, weight management, and satiety.

Review article

Paddon-Jones D, et al. Am J Clin Nutr. 2008.

Show full citation

Abstract

Obesity, with its comorbidities such as metabolic syndrome and cardiovascular diseases, is a major public health concern. To address this problem, it is imperative to identify treatment interventions that target a variety of short- and long-term mechanisms. Although any dietary or lifestyle change must be personalized, controlled energy intake in association with a moderately elevated protein intake may represent an effective and practical weight-loss strategy. Potential beneficial outcomes associated with protein ingestion include the following: 1) increased satiety--protein generally increases satiety to a greater extent than carbohydrate or fat and may facilitate a reduction in energy consumption under ad libitum dietary conditions; 2) increased thermogenesis--higher-protein diets are associated with increased thermogenesis, which also influences satiety and augments energy expenditure (in the longer term, increased thermogenesis contributes to the relatively low-energy efficiency of protein); and 3) maintenance or accretion of fat-free mass--in some individuals, a moderately higher protein diet may provide a stimulatory effect on muscle protein anabolism, favoring the retention of lean muscle mass while improving metabolic profile. Nevertheless, any potential benefits associated with a moderately elevated protein intake must be evaluated in the light of customary dietary practices and individual variability

 

http://www.ncbi.nlm.nih.gov/m/pubmed/18469287/#fft

[Slartbartfast 2]

@hylian @Ricardo Queiroz
Outro local para conseguir artigos científicos (de praticamente qualquer revista), é colocando o link do mesmo no Sci-Hub: http://sci-hub.cc/

[Lucas, o Schrödinger 11489]

Abaixo segue review do Eric Helms, onde ele conclui uma necessidade de 2,3-3,1g/kg de massa magra de proteínas - quanto maior o déficit maior a necessidade e quanto menor o BF, também maior a necessidade.

 

https://www.researchgate.net/publication/257350851_A_Systematic_Review_of_Dietary_Protein_During_Caloric_Restriction_in_Resistance_Trained_Lean_Athletes_A_Case_for_Higher_Intakes

 

Trecho da conclusão:

 

Citar

Conclusions and

Recommendations

The traditional protein recommendations for strength

athletes have not been determined by examining athletes

in a calorically restricted state or at low body fat percent-

ages and may be too low to minimize losses of FFM

during these conditions. The recent recommendation by

Phillips and Van Loon (2011) of consuming 1.8–2.7g/

kg of protein is supported by the limited research avail-

able, however to further customize protein intake within

this range for the individual, the body composition of

the athlete should be considered. Since protein recom-

mendations are traditionally set based on the study of

individuals of a normal or high body fat percentage, it

may be worthwhile to prescribe protein intake based on

FFM versus total body mass in athletic populations. This

may avoid giving recommendations that are too low for

lean athletes.

When analyzing the six studies reviewed to deter-

mine protein intake per kilogram of FFM, it appears

that the range of 2.3–3.1g/kg of FFM is the most con-

sistently protective intake against losses of lean tissue.

Furthermore, the goal of the athlete should be taken into

account. Athletes with a lower body fat percentage, or a

primary goal of maintaining maximal FFM should aim

toward the higher end of this range. Those who are not as

lean, or who are concerned primarily with strength and

performance versus maintenance of FFM can safely aim

for the lower end of this recommendation.

It also appears that a reduction in dietary fat versus

carbohydrate to create the bulk of the caloric deficit is

more effective in maintaining performance. That said, too

low of a fat intake could compromise health or well-being,

thus a lower limit for fat intake of 20% of total calories

is recommended. Furthermore, less extreme weight loss

rates (0.5kg per week or 0.7% of total body mass) may

serve an even more important role than protein intake

in the preservation of FFM. Slower rates of weight loss

appear to be more protective of both FFM and perfor-

mance and will allow a greater “caloric budget” to assign

values to the three macronutrients. Future research should

be designed to measure the effects of varying protein

intakes on FFM and performance in athletes of various

sports, body compositions and macronutrient ratios for

longer time periods than have been currently studied.

 

[Lucas, o Schrödinger 11489]

Agora um texto bacana (e bem lúcido e moderado) do Dudu Haluch sobre proteínas:

 

http://www.duduhaluch.com.br/necessidades-de-proteinas-e-igf-1-dudu/

[Caverna Man 33]

Em 22/08/2016 at 19:30, Shrödinger disse:

 

Vou colocar abaixo a resposta do Eric Helms a esse artigo do Menno Henselmans. Eric foi bastante moderado e cita diversos (muitos mesmo) estudos na réplica dele. Recomendo a leitura:

 

  Mostrar conteúdo oculto

Okay folks, first off let me point out that Menno Henselmans was kind enough to message me to ensure the accuracy of this blog post and to get my temperature on it before he posted ithttp://bayesianbodybuilding.com/eric-helms-protein/. A very respectful, honest thing to do. Much respect.

The only thing I wanted him to change in fact, was that originally he wrote that the research in question was part of my PhD when it was actually a part of my Masters. And of course he made this edit, so really I left the blog post untouched. Now that is not to say I agree with his interpretation. In fact, I disagree with his interpretation in a few important ways, both mechanistically and in terms of practical application. However, I believe his interpretation is a perfectly reasonable one to make even though I disagree. So, I am putting forth the following response to help those reading both of our thoughts come to their own conclusions on protein intake.

-As an important aside, I would please recommend everyone first read Menno's article on protein intake http://bayesianbodybuilding.com/the-myth-of-1glb-optimal-p…/ and read the full text of my systematic review and double blind crossover trial http://www.researchgate.net/profile/Eric_Helmsso they understand the foundation of what is being discussed.

To start, Menno addresses my systematic review of protein intakes in lean dieting resistance trained populations. He starts by putting forth the fact that the efficiency of protein utilization increases as you decrease calories, which is true. This he states is the logical reason why protein needs don't increase in a deficit, and he states that it is illogical to state that protein needs increase in a deficit, and that in fact based on physiology they would decrease.

In my opinion, this is a simply missing the important point of "why" protein efficiency goes up when you reduce calories. Similar phenomenon occur in many ways in the body. The body increases efficiency in the face of a limited resource. In fact an increase in efficiency signals that there is a limited resource.

If you reduce calories, your energy expenditure decreases, becoming more "efficient" with the utilization of energy to prevent starvation. This doesn't mean you wouldn't benefit from eating more food, it means the body is trying to adapt to less food.

If you travel to a very high altitude, you get more efficient with oxygen extraction in an effort to keep you alive. This doesn't mean you don't feel the negative effects of reduced oxygen and that you wouldn't benefit from more oxygen, it means the body is trying to adapt to less oxygen.

An increase in efficiency signals the fact that there is a limited resource. So it is not illogical to posit that increasing protein in the face of a deficit would be a potentially lean mass sparing decision.

Protein breakdown increases in the face of a caloric deficit as more protein is used for energy. This is well establishedhttp://www.ncbi.nlm.nih.gov/pubmed/15173435. It is also well established that the leaner you are, the more protein you oxidize for energy since there is less available from body fathttp://www.ncbi.nlm.nih.gov/pubmed/10574520. So while you can accurately state that protein efficiency increases in a deficit and be correct, it is also true that you are using more protein for fuel. This is not a one sided equation. If protein efficiency went up only, and you didn't use more protein, the net change would be an increase in protein balance and you wouldn't have a huge body of evidence showing lean mass losses while dieting, you'd have a huge body of evidence showing lean mass gains while dieting!

For these reasons, I think it is plainly incorrect to state that protein needs decrease when you diet. It is only accurate to state that protein efficiency increases when you diet.

Honestly, I think Menno would likely agree with that distinction. I think our true disagreement just comes down to how much protein is required to offset the increase in protein breakdown that occurs, and he would argue that 1.8g/kg is enough (and likely more than enough), while I tend to be more conservative and fall on the side of larger safety buffer.

What we also agree on, is the characterization of my literature review as a hypothesis rather than a definitive conclusion. I explained how a caloric deficit increases protein breakdown, how caloric deficits result in lean body mass losses that scale with the severity of energy restriction, and how the leaner you are the more protein is used for fuel. Then, I hypothesized that an effective strategy to offset this would be an increase in protein intake. Yes, a hypothesis.

A final note regarding my literature review, I want to give a huge kudos to Menno for actually doing some statistical analysis on the data that I presented. That really impressed me. I don't dispute his findings either. With only 6 studies to form my hypothesis it doesn't surprise me that the correlation is a) very weak between LBM and protein intake and non-significant. However, I am curious to see what occurs when Menno reanalyses this information based on grams per kilogram of lean body mass. I actually just provided him that data to run an analysis on. I doubt it will reach significance and show a strong correlation, but I am curious to see if the p value decreases and the inverse correlation increases as it might indicate that something is happening, even if there is not enough data yet to make any definitive, quantitative conclusion.

Now finally, Menno addresses my cross over study comparing 1.6g/kg of protein to 2.8g/kg of protein and acknowledges, like I do in the study, that there was no significant or meaningful differences found in strength, lean body mass or body fat change between the two diets. I think that 1.6g/kg is probably approaching an optimal intake of protein during a deficit, and even if it was a bit short of optimal, I doubt a 2 week period would be an adequate enough time period to show the difference. Additionally, I wasn't able to secure DEXA, hydrostatic weighing or ultrasound (despite my best efforts) as a method to measure lean mass or muscle mass changes. I only had access to high quality, skilled anthropometric measurements. This means skinfolds, and skinfold derived equations. Skinfolds measurements when taken by a skilled technician themselves (when not put into an equation) are a highly reliable and accurate way of measuring fat mass. But, LBM and body fat percentage derived from equations are not. So based on the time frame and the measurements available, I am truly not surprised that there was no difference in LBM (BTW, of course our lab got an ultrasound...6 months after I finished my masters!).

However, the study was not completely a waste! Interestingly enough both on the Profile of Mood States and the Daily Analysis of Life Demands for Athletes the participants reported better overall mood state, more diet satisfaction, and less fatigue consuming the higher protein diet.

Menno dismissed this finding saying the following:
"This study was confounded in a major way by using maltodextrin powder as the protein placebo. That meant the medium protein group was consuming 95 grams of pure sugar. When you’re in a 40% deficit and over 25% of your diet is sugar, it’s not surprising you’ll feel poorly. They were likely starving and the major difference in hunger alone could easily explain the difference in mood."

First off, I think Menno accidentally counted the entire calorie amount of the placebo powder, versus just the maltodextrin portion, as the powder also had 20g of protein in it. The 95g of maltodextrin is 380 calories, and 380 calories is 20.7% of the 1829.3 calories that the moderate protein group consumed not 25%...a minor difference though, so I think his point still stands.

However, I would put forth that his point (like my literature review) is just a hypothesis as to the reason the high protein group felt better. And I would argue, a much weaker hypothesis given that the research on how sugar effects hunger and mood is not as definitive as one might think.

In fact White and colleagues found improvements that only reached significance in a high sucrose diet group in the mental component of a quality of life assessment http://www.ncbi.nlm.nih.gov/pubmed/20095912. This finding is not solitary. Drummond observed subjects consuming a low fat, sugar containing diet who when compared to baseline, reported improvements in perceived quality of life, diet attitude and adherencehttp://www.ncbi.nlm.nih.gov/pubmed/15369982. Finally, the participants in Raben and colleagues’ highest sucrose group reported higher diet satisfaction and palatability compared to the other groupshttp://www.ncbi.nlm.nih.gov/pubmed/9347402.

So the contention that the presence of a large amount of sugar in a diet would "easily explain the difference in mood" as Menno puts it is challenged by these controlled trials showing the opposite. In contrast, the hypothesis that a higher protein intake might result in better diet satisfaction and less hunger is one that stands on the top of a great deal of empirical evidencehttp://www.ncbi.nlm.nih.gov/pubmed/23107521http://www.ncbi.nlm.nih.gov/pubmed/15867892http://www.ncbi.nlm.nih.gov/pubmed/18769212. However, as Menno might argue (and I would agree), the majority of this evidence compares low to high protein intakes without comparing a middle of the road intake, like this study http://www.ncbi.nlm.nih.gov/pubmed/16002798 which when analysed on a g/kg basis compares 1g/kg to 2g/kg.

However, recent research by Antonio comparing 1.8g/kg to 4.4g/kg found that a much larger number of participants dropped out of the 4.4g/kg group, and that bodyweight gain was much less than expected based on self-reported energy intake in the 4.4g/kg grouphttp://www.ncbi.nlm.nih.gov/pubmed/24834017. In my opinion this indicates a satiating effect of protein that extends past the 1.8g/kg level and that the participants in the 4.4g/kg group didn't consume as many calories as they thought they did. A follow up study comparing 2.3g/kg to 3.4g/kg found more weight was gained in the 2.3g/kg group, while the 3.4g/kg group lost more fat, despite a larger self-reported energy intake. Again, I would put forth this likely shows a satiating effect of the higher protein intake and subsequent over reporting of caloric intake which would explain less weight gained, and fat lost in the 3.4g/kg group http://www.ncbi.nlm.nih.gov/pubmed/26500462. To conclude, while it is possible that the differential effects on mood found in the higher protein group in my study are due to the higher sugar intake in the lower protein group, I think it would be premature to conclude this based on the well-established satiating power of protein and the murkier role of sugar.

As a final note I want to emphasize the difference between what Menno and I prescribe with our interpretations of the research. Menno, is happy to use 1.8g/kg as the sole protein intake for all situations (all hail 1.8g/kg!) based on the data as he interprets it. I would agree that intakes over 1.8g/kg are rarely studied. But the absence of evidence on the effect of very high protein intakes (>1.8g/kg) compared to moderately high protein intakes (~1.8g/kg), is not the same as the evidence of absence of an effect of very high protein intakes compared to moderately high protein intakes.

Based on our conversations I know that Menno and I both agree that protein intakes above his recommendations (unless they force other macros too low) aren't harmful. We share this opinion with other much more well established researchers http://www.ncbi.nlm.nih.gov/pubmed/14971434 and we would also be in agreement with the vast majority of the research on resistance trained individuals showing that there has never been an incidence when a lower protein intake was found to have a statistically significant benefit over a higher intake: https://www.facebook.com/photo.php…

Now the reason I am not comfortable with simply advising 1.8g/kg to everyone (and the reason you will most often find ranges prescribed in the literature) is that there is plenty of individual variability in protein requirements evidenced by this study that found a cyclist requiring 2.8g/kg of protein to reach nitrogen balance compared to the mean requirement of 1.63g/kg http://www.ncbi.nlm.nih.gov/pubmed/24476478.

Additionally, I would rather err on the side of over prescribing protein versus under prescribing given the info graphic I linked above. Specifically, I would turn your attention to the 7 studies at the bottom of this infographic that found a benefit of a higher protein intake versus a lower one. 5 of these 7 compared protein intakes in the range of 1.4-2.2g/kg to intakes in the range of 2.4-3.2g/kg. Sure, you can find flaws in each study. But if you have to explain away five studies to maintain your position, perhaps you need to rethink how strongly you hold your position. We can't know for sure that the confounding variables in each of these studies fully explains their findings and that's enough to make me more comfortable prescribing 1.8g/kg as a minimum intake versus a solitary intake to ensure I cover the possibility of it being too little in some cases. For the record, I normally prescribe either 1.8-2.8g/kg of total body mass or 2-3g/kg of lean body mass for protein intake for recreational and competitive strength and physique athletes. Using the lower half for a caloric surplus/maintenance, and the upper half for a deficit.

As a closing note, I want to look to the future because in my opinion we need more research on this to truly make a definitive conclusion. Thus far, the only true controlled comparisons we have of one protein vs another in lifting populations using progressive resistance training while dieting are:

Walberg showing 1.6g/kg beating out 0.8g/kg in lean mass retention in bodybuilders over just a single weekhttp://www.ncbi.nlm.nih.gov/pubmed/3182156

Mettler showing 2.3g/kg beating out 1.0g/kg in lean mass retention in trained lifters over a 2 week period http://www.ncbi.nlm.nih.gov/pubmed/19927027

Helms (me) showing 2.8g/kg beating out 1.6g/kg in mood state in trained lifters over a 2 week period with no difference in strength of body comphttp://www.ncbi.nlm.nih.gov/pubmed/25028958

And a thesis you probably haven't seen by Longman showing 2.4g/kg beating out 1.2g/kg in lean mass retention in trained lifters over a 4 week period https://macsphere.mcmaster.ca/handle/11375/15355

We don't have enough data. We disagree because we are filling in gaps with our interpretations of what is available. Hopefully a meta-analysis or a better designed, longer RCT will come out that can give more evidence. I know Menno well enough that he would revise his thoughts on protein if convincing data was to emerge (in fact that is the essence of the Bayesian approach). I commit to do the same. Protein is expensive and won't be getting cheaper as our population increases, so as soon as I feel that I can responsibly tell lifters to eat less of it, I will. But as it stands, I know there is no harm erring on the higher side (if in fact that’s what I’m doing), and without stronger evidence to show a lack of potential harm of lower intakes, I can't commit to a lower prescription.

 

https://www.facebook.com/ericrhelms/posts/10156254344360441

 

Importante deixar claro que não há nada muito conclusivo que aponte pra uma vantagem inexorável de uma maior ingestão de proteínas sobre a recomendação padrão de 2g/kg. Entretanto, existem algumas pistas e hipóteses que apontam pra uma vantagem de um maior consumo. Como não há desvantagens, me parece razoável e preferível "errar" pro lado de mais proteína.

 

P.S.: Me parece que 1,2g/kg é subótimo em praticamente qualquer circunstância, apesar de ser um valor razoável quando em superávit calórico numa dieta high carb (carbos são anti-catabólicos e, por conseguinte, anabólicos) ou cetogênica (quando a necessidade de quebra de proteínas pra produzir glicose fica extremamente reduzida).

 

Abraços

 

Faz todo sentido este artigo do Eric Helms. Inclusive, é a abordagem que a grande maioria opta ou é orientada a fazer. 

 

Assim como o Menno, eu sempre mantive minha proteína intacta, independente da situação. Sempre mexi apenas com a quantidade de carbo e gordura. A diferença, como já havia dito, é que sempre deixei minha proteína bem alta. Meus exames sempre estiveram ok e nunca tive problemas. Muitos estudos e muitos amigos (alguns ex-atletas) defendem o mesmo que defendem o Eric Helms e o Dudu Haluch, ou seja, que o consumo de proteína deve aumentar em condições hipocalóricas. É algo que só agora estou começando a considerar. No final do ano vou focar num corte e confesso que não sei se terei coragem de manter essa relação de 1.8g/kg. 

 

Muito bom o tópico, meus amigos.

 

Abraços

[Magnificus 6]

Interessantes os estudos postados pelo autor do tópico mas não se referem apenas a atletas treinados de fisiculturismo.

 

Também não dá pra avaliar efeitos sobre a saúde em um experimento que não dure anos.

 

O glicogênio do nosso corpo é reposto com a conversão de 100% dos carbs, 30 a 60% das proteínas e 10% da gorduras.

 

Quem usa baixo carbs tem boa parte de suas proteínas convertidas em energia.

 

Natural que usa alto carb se não tiver um gasto calórico muito elevado vai ganhar músculos mas com gordura e no cutt perde  gordura e músculos.

 

Mas eu acho que uma boa experiência é tentar elevar as proteínas desde que não supere um bf razoável de 10 a14%.

 

Mas é bom fazer acompanhamento médico.

 

Os sites dedicados a diabéticos são sérios e dizem que excesso de proteína pode trazer problemas inclusive renais.

 

 

 

 

 

[Lucas, o Schrödinger 11489]

Citar

EXCESSO DE PROTEÍNA VIRA O QUE? 

Provavelmente você já ouviu várias respostas diferentes para essa pergunta. Respostas simplificadas do tipo, proteína em excesso vira gordura, ou então, massa muscular. Alguns ainda vão dizer que o excesso de proteína vira glicose. Na verdade, o destino das proteínas, após serem degradadas pelas proteases em aminoácidos no estômago e no intestino delgado, vai depender do estado energético e metabólico do nosso organismo. 

O déficit energético e a redução de carboidratos da dieta favorece a degradação de proteínas, principalmente do músculo esquelético. Nessa situação o corpo pode usar as proteínas da dieta (como também do músculo) como fonte de energia (ATP) ou glicose (gliconeogênese) e corpos cetônicos. Os corpos cetônicos são preferencialmente formados pelo excesso de acetil-coA da degradação das reservas de gordura e são usados como fonte de energia pelos tecidos extra hepáticos (músculo, coração), incluindo o cérebro, em situações jejum, restrição de carboidratos (dieta cetogênica), diabetes tipo 1. Embora alguns aminoácidos também possam formar corpos cetônicos em dietas low carb, após a remoção do seu grupo amino (nitrogênio), os aminoácidos são convertidos preferencialmente em glicose no fígado nessa situação (gliconeogênese). 

Já em uma situação de superávit calórico, com bom aporte de carboidratos, o excesso de proteínas pode virar gordura ou ser usado como fonte de energia. Excesso de proteína na dieta (acima de 1,5-2,0 g/kg) também pode gerar hipertrofia muscular, desde que haja estímulo do treinamento (musculação) e um ambiente hormonal favorável (testosterona, GH, insulina). Na verdade, dificilmente proteína vira gordura, pois essa via não é favorecida bioquimicamente. Nesse tipo de situação o corpo prefere usar carboidratos e proteínas como fonte de energia, reduzindo a queima de gordura e favorecendo seu armazenamento. 

Os carboidratos também são convertidos em ácidos graxos com muito mais facilidade que as proteínas, num processo conhecido como lipogênese, mas esse processo também não é tão significativo para o ganho de gordura. O ganho de gordura ocorre por um efeito "poupador de gordura" dos carboidratos, que em excesso reduzem a lipólise e a oxidação de lipídeos. 

O excesso de proteínas na dieta tem um custo energético maior (20-30%) para o organismo do que o aporte de carboidratos (5-10%) e lipídeos (0-5%). O corpo sintetiza e degrada proteínas o tempo todo (turnover) e o balanço energético e de macronutrientes é determinante para decidir como o corpo irá utilizar as proteínas.

abraços, Dudu Haluch

 

[Torf 11507]

Amigo, esse texto acima para mim näo ficou bem claro. Acho que é algo que eu näo encontro uma explicacäo que seja clara. Por exemplo o que é uma "proteína degradada"? É rejeito que vai embora na urina ou nas fezes?

 

Mas, enfim, essa frase ficou meio difícil de ser compreendida:

6 horas atrás, Shrödinger disse:

Na verdade, dificilmente proteína vira gordura, pois essa via não é favorecida bioquimicamente. Nesse tipo de situação o corpo prefere usar carboidratos e proteínas como fonte de energia, reduzindo a queima de gordura e favorecendo seu armazenamento. 

Proteína näo vira gordura mais favorece o armazenamento de gordura por parte do corpo? Ou seja, ela näo vira, mas faz com que o corpo acumule mais?

[Lucas, o Schrödinger 11489]

4 horas atrás, Torf disse:

Por exemplo o que é uma "proteína degradada"?

Eu entendi que é a quebra de proteína em aminoácidos.

 

4 horas atrás, Torf disse:

Proteína näo vira gordura mais favorece o armazenamento de gordura por parte do corpo? Ou seja, ela näo vira, mas faz com que o corpo acumule mais?

A proteína em si não costuma se tornar gordura, mas carboidratos e principalmente gorduras que se tenha ingerido junto se tornarão (considerando excedente calórico).