Scientific Basis for High Protein Intake?

Nutrition
1

So I decided to start seeing a doctor specialized in sports medicine as my general physician. I figured he would have a better understanding of how an active person’s body functions and I was also very exited about the prospect of being able to talk to a doctor about my dietary approach without getting rebuked and referred to the useless USDA recommendations. I consider my diet to be on point:

Breakfast: 6 whole eggs with tomato and onion, fruit
Lunch: Animal protein, rice, veggies, fruit
Dinner: Animal protein, rice, veggies
PWO: Protein shake or BCAA+Creatine.
Supplements: Flameout (fish oil), Vitamin D, Probiotic, ElitePro Minerals (Zinc, Magnesiumâ?¦)

Much to my dismay, he considered my protein intake to be excessive (it only totals about 160g/day) and he argued that the body only needs up to 80g of protein per day and that the rest gets excreted. This goes against my beliefs and personal experience and I tried to make my case arguing that it’s not possible that an active 180lb male has the same requirements as an 120lb sedentary, that the protein turnover is greater in the former, etc. but it all sounded very bro-sciency since I didn’t have any studies to cite. I have my next appointment with him in a couple of weeks and I want to bring some scientific literature with me to back my practices. Not that I desperately need his validation, I just want to have an intelligent discussion with him (he is very knowledgeable on most subjects) without him dismissing my arguments for not having the literature to back them up. So I’d like to ask you guys if you have read any good papers on protein intake that you can refer. Thanks!

2

eric helms / alan aragon both have tons of studies(recent) that deal with protein intake in strength training subjects. google their names with some keywords

3

80 grams of protein will bring 50% of men into nitrogen balance. That is the basis for the amount.

140 grams a day has been shown to keep >99% of the population, including hard training athletes in nitrogen balance. That means that protein synthesis matches protein breakdown from body tissues. It does not mean muscle growth occurs, just that muscle is maintained. The protein absorbed is basically matched by protein broken down, and nitrogen removed in urea. The protein in NOT excreted, it is used for energy to spare muscle, and a small amount, 5-10 grams a day is actually “turned over”-put into tissues in place of others that are removed.

At this point, consider that protein synthesis is at 50 units, and protein breakdown is at 50 units a day-Nitrogen balance.

It has been shown that the protein synthesis can be stimulated by adding up to 25% more protein than the level that puts you in nitrogen balance. So at a max of about 175 grams a day, you are now getting 100 units of protein synthesis, and 50 units of breakdown. The net might be 2-5 grams a day. Some of the added 35 grams will also get turned to glucose and “spare” some of the breakdown, so maybe that falls to 40 units. Since the net burned and synthesized is less than the amount taken in, some of the added protein may start turning into ammonia at that level. If you are working out, the added protein is more likely to be used for fuel and spare muscle protein, so ammonia is not really a problem at this point.

It has also been shown that additional protein above 175 grams will not stimulate more protein synthesis, but it WILL still act to spare some of the 40 units of protein being otherwise used up from muscle a day. Somewhere between 1-60 extra grams above 175 (depending of amount of training) the ability to use protein to spare muscle maxes out, and at that point, ALL extra protein consumed produces ammonia (no more Urea is produced in individuals above that point. Urea production is a sign that protein was used to spare muscle protein. So ammonia production per gram consumed rises steadily from somewhere around 140-175 grams up to 175-235 grams range (lessened by higher workload) at which point it all is wasted, and actually harmful.

Obviously if someone weights 275 pounds lean they might want to adjust up, but these studies included 220 pound athletes. It creates the following general recommendation for a hard training athlete trying to gain net muscle:

  1. 140 grams
  2. +35 grams to increase protein syntheses
  3. +0-60 grams a day depending on workload. I would say that an hour of work with 30 sets of hard 10 reps average would be about 30 grams extra needed. BCAAs as much as possible. So about a gram per set of 10. If you do sets of 1-5 you might cut it in half.

And I might multiply it by the ratio of body weight to 200 or so.

It is clear that all protein becomes ammonia at about 1.2 grams per pound of bodyweight no matter how much hard training takes place.

4

[quote]Claudan wrote:
eric helms / alan aragon both have tons of studies(recent) that deal with protein intake in strength training subjects. google their names with some keywords [/quote]

I will look them up. Thanks!

5

[quote]mertdawg wrote:
80 grams of protein will bring 50% of men into nitrogen balance. That is the basis for the amount.

140 grams a day has been shown to keep >99% of the population, including hard training athletes in nitrogen balance. That means that protein synthesis matches protein breakdown from body tissues. It does not mean muscle growth occurs, just that muscle is maintained. The protein absorbed is basically matched by protein broken down, and nitrogen removed in urea. The protein in NOT excreted, it is used for energy to spare muscle, and a small amount, 5-10 grams a day is actually “turned over”-put into tissues in place of others that are removed.

At this point, consider that protein synthesis is at 50 units, and protein breakdown is at 50 units a day-Nitrogen balance.

It has been shown that the protein synthesis can be stimulated by adding up to 25% more protein than the level that puts you in nitrogen balance. So at a max of about 175 grams a day, you are now getting 100 units of protein synthesis, and 50 units of breakdown. The net might be 2-5 grams a day. Some of the added 35 grams will also get turned to glucose and “spare” some of the breakdown, so maybe that falls to 40 units. Since the net burned and synthesized is less than the amount taken in, some of the added protein may start turning into ammonia at that level. If you are working out, the added protein is more likely to be used for fuel and spare muscle protein, so ammonia is not really a problem at this point.

It has also been shown that additional protein above 175 grams will not stimulate more protein synthesis, but it WILL still act to spare some of the 40 units of protein being otherwise used up from muscle a day. Somewhere between 1-60 extra grams above 175 (depending of amount of training) the ability to use protein to spare muscle maxes out, and at that point, ALL extra protein consumed produces ammonia (no more Urea is produced in individuals above that point. Urea production is a sign that protein was used to spare muscle protein. So ammonia production per gram consumed rises steadily from somewhere around 140-175 grams up to 175-235 grams range (lessened by higher workload) at which point it all is wasted, and actually harmful.

Obviously if someone weights 275 pounds lean they might want to adjust up, but these studies included 220 pound athletes. It creates the following general recommendation for a hard training athlete trying to gain net muscle:

  1. 140 grams
  2. +35 grams to increase protein syntheses
  3. +0-60 grams a day depending on workload. I would say that an hour of work with 30 sets of hard 10 reps average would be about 30 grams extra needed. BCAAs as much as possible. So about a gram per set of 10. If you do sets of 1-5 you might cut it in half.

And I might multiply it by the ratio of body weight to 200 or so.

It is clear that all protein becomes ammonia at about 1.2 grams per pound of bodyweight no matter how much hard training takes place.

[/quote]

Thanks for all that great info! Do you have some sources so that I can look deeper into this?

6

I will look. Some are in bibliographies that I have linked to but had to be removed because of policy. The 3 levels are absolutely confirmed with athletes. A) 140 will keep 99%+ in protein balance, B) +25% of that will maximize synthesis and at C) 235 grams (maximum, may be anywhere between level B and 235 grams because experimental design just used those 2 levels), each additional gram produces ammonia which means it does no benefit, and does some harm.

7

[quote]mertdawg wrote:
I will look. Some are in bibliographies that I have linked to but had to be removed because of policy. The 3 levels are absolutely confirmed with athletes. A) 140 will keep 99%+ in protein balance, B) +25% of that will maximize synthesis and at C) 235 grams (maximum, may be anywhere between level B and 235 grams because experimental design just used those 2 levels), each additional gram produces ammonia which means it does no benefit, and does some harm. [/quote]

Thanks! Also, you left me wondering: What are the adverse effects of ammonia buildup?

8

[quote]eaboadar wrote:

[quote]mertdawg wrote:
I will look. Some are in bibliographies that I have linked to but had to be removed because of policy. The 3 levels are absolutely confirmed with athletes. A) 140 will keep 99%+ in protein balance, B) +25% of that will maximize synthesis and at C) 235 grams (maximum, may be anywhere between level B and 235 grams because experimental design just used those 2 levels), each additional gram produces ammonia which means it does no benefit, and does some harm. [/quote]

Thanks! Also, you left me wondering: What are the adverse effects of ammonia buildup?[/quote]

Reduced strength and endurance, and possibly liver damage.

9
10

Would a higher protein intake be suggested when cutting? If so how much more?

11

Since I don’t believe in “cutting” carbs to cut, and I don’t believe in using glycogen depleting training to cut, my answer would be no.

Again, protein has basically 3 stages of action. Maintaining nitrogen balance, stimulating additional synthesis, sparing/reducing the rate of breakdown. The rate of breakdown is primarily accelerated by the balance of carbs to glycogen depleting training.

Glycogen depletion requires that the work level be above a threshold for a period of time. Otherwise the muscle is just using fatty acids.

The first 10 or so seconds of weight lifting reps uses atp/CP which gets rebuilt from fatty acid oxidation during rest period. So low rep sets don’t really affect glycogen at all. Also if you maintain a low workload, like 300 cal/hour, you also have enough rate of fatty acid oxidation to replenish phosphates.

So on a cut, I believe that the calorie deficit should come from a reduction of fat cals.

Again, example:
normal
600 cals carbs (150 g)
600 cals protein (150 g)
1200 cals fat (130 g)
(plus carbs and protein post workout, and to gain)

On a cut, I believe that your only training goal, except for perhaps the very last period, should be to use low rep sets to maintain strength and muscle protein. Sets of 2-5 will NOT deplete glycogen, and therefore will NOT turn to stored protein to supplement glucose. Do sets of 2-5, rest 2-3 minutes. It is pure fat beta oxidation fueling your work.

Now walking slow is probably also below the threshold for turning to glycogen, so you can use it to burn 100 cals here and there.

And the brain will use 100 grams or so of sugar, which will deplete the liver slowly, and at that point the muscles, which is why you are better off with about 150 gs of carbs a day.

Cut by cutting fat and training with heavy low rep sets. Gain by adding carbs and some protein and training with 6-15 rep sets. But if you can still build strength and contractile fibers while cutting, your gain period will be much more productive. Your muscles will get smaller, in part because intramuscular fat stores will shrink.