20g protein per meal optimal ?

[Fatpanda]

Ii'm sure some of you getbiggers have read about these 2 fairly recent studies:

Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men. Am J Clin Nutr. 2009.

and

A moderate serving of high-quality protein maximally stimulates skeletal muscle protein synthesis in young and elderly subjects. Journal of the American Dietetic Association, 2009.

basically they both show that 20g of protein maximally stimulates protein synthesis, and that any more than this is burned off. Also from other studies done on constant infusion of bcaa, we know there is a refractory period involved that limits the frequency of meals.

despite these studies, there are others that show 1g of protein per pound of lean body mass is optimal - and that amount would be higher that the 20g 

i am personally trying this out and have reduced my protein intake from 1g per pound to 20-30g protein every 5 hours ( 4 meals a day).

what are your thoughts on these studies and their implications ?

[tbombz]

you may have over looked it, but based on the way the studies have been done the answer is obvious. 

studies done on optimal protien intake should be done on over days, weeks, months, and measure effects on body composition- muscle and fat.

studies that only look at momentary metabolic effects, only a small part of the picture, arent effective at measuring optimal intake over daily, weekly time periods.

20grams maximally stimulates protein synthesis. okay. what does it do to protein breakdown, not only immidietly but hours later? you mentioned that protein frequency needs to be more spaced out for maximum effectiveness ( an idea i believe first brought baout by layne norton).  30, or 40grams of protein may not give any immediate protien synthesis benefits, but it may give some anti-catabolic benefits during those 4,5,6 hours between meals. 


who knows exactly why there seems to be a difference between single meal optimum protein and daily total optimum protein.  but we can be sure that the studies looking at the effectivess of varying protein intakes over the course of an entire day (studies that have found that 1gram per lb lean bodyweight is about right) are going to be a more accurate representation of how one should eat.

im not sure if ive explained it clearly enough.

[Fatpanda]

well i can see why you are saying that and yes i agree that 1g per pound is effective and cannot be overlooked, however these studies are well done, and suggest that even 1g per pound is too much.

i wonder if the 1g per pound is only in certain circumstances, i.e. the results are from the extra calories during calorie reduction, etc etc

i was reading mentzers thoughts on diet recently ( heavy duty nutrition pdf) and he mentions how little we actually need in terms of calories, protein etc for growth over time. then thought about these studies and they do tie up.

regarding the breakdown rates, from the studies i have read i believe reduced protein breakdown comes primarily from insulin release, and not protein intake per say. As the breakdown levels always seem to coincide with with blood insulin levels. As protein intake also produces insulin release with or without carbs, it is an easy thing to miss.

the thing about the study i mentioned above is the digestion rate of eggs is extremely low, so whey may be better to take as it is in and out of the system quicker, and would help avoid the refractory issue.

i would love the team that did the egg study to do the same with steroids involved - it would be great to know how synthesis/breakdown or both are effected.

[tbombz]

here let me make it more simple


a study shows that 20grams is the maximum necessary to illicit the most protein synthesis.

another study shows that protein intake should be spaced out over at least 4 to 5 hours so you dont blunt protein synthesis with too frequent of meals. 


neither of these studies say anything about optimum daily protein intake. but one could use both information to create a diet, 20g protein per meal every 4-5 hours. and that would be no more than 80-120grams of protein per day.


but we have one study that looks at daily protein intakes for a 200lb individual.  the people who eat 120grams a day dont grow nearly as well as the people who eat 200grams a day.  goign over 200grams a day doesnt seem to help any more.


do you follow the first diet, based on two seperate unrelated studies that dont show any direct evidence for the daily diet's effectiveness ?

 or do you follow the second diet, based on empirical evidence directly supporting the diets effectiveness?


 

[Fatpanda]

i see what your saying, but those 2 unrelated studies both show the same thing i.e. any more than 20-30g protein is burned off.

how about this to get you thinking :


Anthropometric and calorimetric evidence for the protein sparing effects of a new protein supplemented low calorie preparation
LF Van Gaal, D Snyders, IH De Leeuw and JL Bekaert


A commercial protein sparing modified fast (PSMF) preparation has been evaluated for the protein sparing effects in 15 morbidly obese patients. During a 500 kcal preparation, given during a 6-week period, mean body weight and BMI decreased significantly.   Total body fat decreased from 55.8 to 41.4 kg and lean body mass and arm muscle circumference (AMC) remained unchanged. Using indirect calorimetry and under the same degree of energy expenditure, carbohydrate metabolic consumption was significantly diminished (166 to 61 g/24 hr; p less than 0.001) but fat consumption was increased (116 to 155 g/24 hr; p less than 0.05) while the metabolic turn-over of protein was unchanged. This new presented PSMF preparation seems to present the typical properties of a protein sparing modified fast.

now bare in mind this involved the participants eating only 120g of protein a day - with no excercise ( which would provide further protein sparing effects).   

[Fatpanda]

or how about this regarding the refractory issue, :


The effect of meal frequency on body composition during 12-
weeks of strength training

Background: Human trials on the effect of meal frequency on body composition are
scarce. Short-term studies show increased rate of protein synthesis immediately after
intake of amino acids (Rennie 2002), and frequent meals are shown to aid in the
preservation of lean body mass when dieting (Iwao 1996). Consequently it could be
hypothesised that in response to strength training interventions, more frequent meals
will give larger muscle mass accumulation and lower fat mass than fewer meals.

Objective: The purpose of this study was to compare the effects of dividing the daily
food intake in 3 versus 6 meals per day on changes in body composition in young
men and women performing strength training over 12 weeks.

Design: Men (n=33) and women (n=15) aged 21 to 35 with at least one year of
previous strength training experience were matched according to strength and gender
and then randomly assigned to either a 6M group or a 3M group. The prescribed total
dietary intake was equal between the groups and was calculated to give a positive
energy balance of approximately 1200 KJ/day, a protein intake of 1.5-1.7 g/kg/day
and a carbohydrate intake of 5-7 g/kg/day (Table 1). During the training period the
dietary intake was controlled by repeated 24-hours recalls. All participants performed
the same periodized 2-split strength-training programme, training four times per
week, giving each muscle group one heavy session and one light session per week. In
the heavy sessions, training intensity varied between 10 and 3 RM sets, and 3-6 sets
were performed in each exercise. Project leaders, giving every participant the
necessary assistance, supervised all heavy sessions. Determination of body
composition was performed with DEXA at the beginning of, in the middle of and
immediately after the trial.

Results: A total of 16 men and 11 women completed the project. The 3M group had a
strong tendency towards greater gain in LBM than the 6M group after twelve weeks
of strength training, 1.71% {-0.18, 3.59}, p=0,075. After linear regression analysis
5
the difference was significant when adjusted for gender and energy intake (p=0.045),
when adjusted for gender and protein intake (p=0.027), and when adjusted for gender,
protein intake, carbohydrate intake and fat intake (p=0.011). There were no
significant differences in change in fat mass between the groups, but a tendency
towards a greater gain in the 3M group, 7.33% {-5.23, 19.90}, p=0.241. The 3M
group had a 2.87% {0.62, 5.12} larger weight gain than the 6M group, p=0.014. Both
groups had significant increases in strength in all test exercises. The 3M group had a
larger strength gain in bench press, 10.85% {3.38, 18.32}, p=0.006 and triceps
pushdown, 12.81%, {3.14, 22.47}, p=0.011 and a larger strength gain for the upper
body, 8.37% {1.61, 15.13}, p=0.017 and total body, 6.28 {0.46, 12.09}, p=0.035 than
the 6M group. The participants had a 2.31% {0.83, 3.79}, gain in bone mineral
density of the spine during the twelve weeks of strength training, p=0.003, but there
were no differences between the groups.

Conclusion: In this study, three meals per day resulted in larger muscle- and strength
gain from strength training when in positive energy balance than six meals per day
over a period of twelve weeks. The reason why we draw opposite conclusions from
short-term studies needs further investigation. More long-term studies are needed to
determine the optimal meal frequency for ultimate gain in LBM from strength
training, and larger groups may be needed to determine an effect of meal frequency
on fat mass. The changes in fat mass had large variations within and between the
groups, making it difficult to draw any conclusions.