Protein Intake - Review of Positions & Studies

[jrbert91]

I put in some effort into responding to an uninformed and incorrect comment in another thread recommending 30g of protein intake per day. Every credible source you look at says about 1.2 to 2.0g/kg/d. I thought I would share the sources.

• American College of Sports Medicine: Current data suggest that dietary protein intake necessary to support metabolic adaptation, repair, remodeling, and for protein turnover generally ranges from 1.2 to 2.0 g/kg/d. Higher intakes may be indicated for short periods during intensified training or when reducing energy intake. Daily protein intake goals should be met with a meal plan providing a regular spread of moderate amounts of high-quality protein across the day and following strenuous training sessions
• Examine.com: If you are an athlete or highly active person attempting to lose body fat while preserving lean muscle mass, a daily intake of 1.5-2.2g/kg bodyweight (0.68-1g/lb bodyweight) is a good goal. If you are an athlete or highly active person, or you are attempting to lose body fat while preserving lean mass, then a daily intake of 1.0-1.5g/kg bodyweight (0.45-0.68g/lb bodyweight) is a good goal.
• Academy of Nutrition & Dietetics: recommend 1.2 to 2.0 grams of protein per kilogram of body weight per day for athletes, depending on training. Protein intake should be spaced throughout the day and after workouts.
• International Society of Sports Nutrition: Protein intakes of 1.4 - 2.0 g/kg/day for physically active individuals is not only safe, but may improve the training adaptations to exercise training
• Even the outdated US Recommended Daily Allowance for protein is 0.8g/kg/d which ranges between 46-56g for adults, depending on gender (and of course actual weight).

Individual Studies:

• Protein for Exercise & Recovery: 1.4-2 g/kg/day
• Protein Requirements for Endurance Athletes: 1.0g/kg/d for sedentary people, 1.6g/kg/d for athletes
• Dietary Protein for Athletes: 1.3 to 2.0 g/kg/d
• Dietary protein requirements and adaptive advantages in athletes: 1.2 - 1.7g/kg/d
• Nutritional Practices of Elite Athletes - Practical Recommendations: 1.2 - 2.0 g/kg/d

 

[jhubb]

@jrbert91 Someone really recommended only having 30g of protein in a day?! That's ridiculous

 

[jrbert91]

@jhubb Yep, and very hostile and insistent about it too.

 

[amberzon]

@jrbert91 Not only that but also claimed people like Ben Bergeron also recommend it.

 

[asavedwretch]

@amberzon Christ wish I'd seen that thread. 30g/day is woeful for a sedentary middle aged man let alone someone training.

I'm on 60g by mid morning :-|

 

[jrbert91]

@asavedwretch The funny thing is that he was claiming that's what a lot of body builders eat.

 

[tboymessiah]

@jrbert91 He must have been a vegan

 

[jrbert91]

@tboymessiah Interesting, I didn't even think of that.

 

[oldman1941]

@jrbert91 Several people have told me 1.2-2g of protein per POUND of bodyweight, per day. Which always seemed insanely high to me and now I'm finding out it is.

Good post!

 

[jrbert91]

@oldman1941 Thanks. See the comment by /@ryann22. Just take into account that 1.2-2g/kg/d is very conservative, and there is really no harm in having more. Also, the 1.2-2g/lb is typically stated as lb of lean body mass.

 

[shonspawnel]

@jrbert91 Thanks for the links! Much appreciated.

 

[jrbert91]

@shonspawnel No prob.

 

[veve13]

@jrbert91 Good info.

 

[jrbert91]

@veve13 Thanks.

 

[kosherinchrist]

@jrbert91 What if I'm currently rather fat? Do I plug in my current weight or a healthy weight?

 

[dawn16]

@kosherinchrist Well, "healthy weight" is meaningless. Body composition is what is important. If you have a relatively accurate assessment of your lean body mass you should use that for your calculations. However this requires either air displacement plethysmography (i.e. The Bod Pod), hydrostatic weighing, a DEXA scan, or skin fold assessment by a very experienced technician.

If you don't have access to any of these you are better off just using your bodyweight but shooting for the lower end of the recommended range. Most people that try to estimate their BF level just by looking in the mirror are way, WAY off and you are unlikely to be an exception.

 

[kosherinchrist]

@dawn16 Well, according to my bathroom scale I'm 280 and 35% fat, so I'll shoot for the love end for sure.

 

[jrbert91]

@kosherinchrist Two things. First: remember to consider your total calories if you're planning to lose weight. Second: there is evidence that at times of caloric deficit, increased protein intake will help you retain more muscle mass during weight loss. So it wouldn't hurt to go to the upper range of protein intake as long as your total calories isn't over your goal.

 

[kosherinchrist]

@jrbert91 You got it, thanks.

 

[dawn16]

@jrbert91 It is pointless to attempt any sort of rational discussion with a vegan because their positions aren't based on reliable, non-biased, peer-reviewed data, but rather an almost religious zealotry. They are fueled by emotions and feelings, and vigorously cling to some of the most horrifically awful "studies" which are so unbelievably flawed that they aren't worthy of publication in any format.

I wasted a good hour of my life responding to a similar ridiculous post on this forum, systematically refuting every claim that was made and highlighting in detail where their "proof" had cited junk science or misinterpreted data from reliable sources. None of it sunk in though, because they weren't interested in fact, only that which validated their idiotic and infantile beliefs.

However, the issue of protein requirements for athletes is still a quite contentious area for many reasons. Part of the problem is that nearly all human nutrition studies are inherently flawed due to limitations in study design with human subjects (to many factors that can't be controlled, and humans are lousy adherents to stringent protocol requirements, and for nitrogen retention the subjects have to stay in the lab/sampling area 24/7). Another major problem is the methods used to assess "protein balance". All of them have drawbacks and the applicability can be legitimately argued against, or in the case of radiolabeled tracers, can be difficult to get past institutional review boards.

And with every study that attempts to evaluate any factor in conjunction with exercise, the exercise protocols used are notoriously wimpy. This is because most studies require training naive subjects to remove confounding variables with past training history, but naive subjects can't tolerate a training protocol that would be used by a higher level athlete. This often means that the conclusions of the study can't be extrapolated to higher level athletes because the stimulus used in the study was far below what is encountered in real training. So, most studies suggesting ~1.0-1.2g/lb of bodyweight aren't, in my opinion, at all applicable to someone training on a Regionals-level Crossfit program. And the few studies that have used very intense training protocols have found benefits in protein intakes up to 2.2-2.5g/lb.

Also, official organizations that publish guidelines tend to err on the conservative side if there is even the slightest hint that their recommendations could be detrimental to even fringe populations.