In calculating the exact amount of protein they might recommend to maintain nitrogen balance, a 200lb athlete who trains consistently would find that they only need a measly 59g of protein to prevent nitrogen losses and protein malnutrition.
So, for those of you who staunchly believe that you're only required to eat enough protein to meet your needs,go right ahead and reduce your protein intake from 2.0g/kg to 0.65g/kg. In the meantime, I'll be encouraging everyone else to actually increase his or her protein intake beyond the current 2.0g/kg recommendation.
If this recommendation seems excessive, it's because you have a narrow view of how protein fits into one's dietary strategy. You're looking at protein in the same narrow way that people used to look at vitamin C; essential at a specific dose but conferring no additional benefits with a higher intake.
With vitamin C, we all know it's important to consume enough of it (at least 10mg/day) to prevent scurvy. However, it's also commonly known there are a host of health benefits associated with much higher doses (200mg/day or more) including a reduced risk of cancer, increased HDL cholesterol, reduced risk of coronary artery disease, and a reduced duration of cold episodes and severity of symptoms.
Like vitamin C, instead of thinking of protein as a macronutrient that provides no benefit beyond preventing protein deficiency, we need to recognize the benefits of eating protein (at any dose).
Increased Thermic Effect of Feeding — While all macronutrients require metabolic processing for digestion, absorption, and storage or oxidation, the thermic effect of protein is roughly double that of carbohydrates and fat. Therefore, eating protein is actually thermogenic and can lead to a higher metabolic rate. This means greater fat loss when dieting and less fat gain during overfeeding.
Increased Glucagon — Protein consumption increases plasma concentrations of the hormone glucagon. Glucagon is responsible for antagonizing the effects of insulin in adipose tissue, leading to greater fat mobilization. In addition, glucagon also decreases the amounts and activities of the enzymes responsible for making and storing fat in adipose and liver cells. Again, this leads to greater fat loss during dieting and less fat gain during overfeeding.
Increased IGF-1 — Protein and amino-acid supplementation has been shown to increase the IGF-1 response to both exercise and feeding. Since IGF-1 is an anabolic hormone that's related to muscle growth, another advantage associated with consuming more protein is more muscle growth when overfeeding and/or muscle sparing when dieting.
Reduction in Cardiovascular Risk — Several studies have shown that increasing the percentage of protein in the diet (from 11% to 23%) while decreasing the percentage of carbohydrate (from 63% to 48%) lowers LDL cholesterol and triglyceride concentrations with concomitant increases in HDL cholesterol concentrations.
Improved Weight-Loss Profile — Brand spankin' new research by Layman and colleagues has demonstrated that reducing the carbohydrate ratio from 3.5 - 1 to 1.4 - 1 increases body fat loss, spares muscle mass, reduces triglyceride concentrations, improves satiety, and improves blood glucose management (Layman et al 2003 — If you're at all interested in protein intake, you've gotta go read the January and February issues of the Journal of Nutrition. Layman has three interesting articles in the two journals).
Increased Protein Turnover — As I've discussed before in my article Precision Nutrition, all tissues of the body, including muscle, go through a regular program of turnover. Since the balance between protein breakdown and protein synthesis governs muscle protein turnover, you need to increase your protein turnover rates in order to best improve your muscle quality. A high protein diet does just this. By increasing both protein synthesis and protein breakdown, a high protein diet helps you get rid of the old muscle more quickly and build up new, more functional muscle to take its place.
Increased Nitrogen Status — Earlier I indicated that a positive nitrogen status means that more protein is entering the body than is leaving the body. High protein diets cause a strong positive protein status and when this increased protein availability is coupled with an exercise program that increases the body's anabolic efficiency, the growth process may be accelerated.
Increased Provision of Auxiliary Nutrients — Although the benefits mentioned above have related specifically to protein and amino acids, it's important to recognize that we don't just eat protein and amino acids — we eat food. Therefore, high protein diets often provide auxiliary nutrients that could enhance performance and/or muscle growth. These nutrients include creatine, branched chain amino acids, conjugated linoleic acids, and/or additional nutrients that are important but remain to be discovered. This illustrates the need to get most of your protein from food, rather than supplements alone.
That article relates specifically to whether or not amino acid supplementation increases growth hormone production, finding no results. I'd say that's an argument against amino acid supplementation.
This article is a meta-analysis, and concludes that protein supplementation does not have enough evidence to support an increase in lean mass with strength training.
This article examines L-carnitine supplementation, and finds that while there is an increase in serum carnitine increased (duh, you're supplementing it...), there was no change in performance.
fooliam wrote:In Exercise Physiology by Brooks, Fahey, & Baldwin (I refer to it as my big black physiology brick), the conclusion is that increased protein supplementation, even up to 2.0 g/kg/day can still leave an athlete in negative nitrogen balance if total energy balance is negative.
fooliam wrote:It is also stated that 1.0 - 1.5 g/kg (IE RDA or just slightly above) is sufficient to maintain nitrogen balance provided that a net zero or positive total energy balance is achieved. In other words, it would seem that so long as you are eating enough food in a well-balanced diet, you'll be getting enough protein to increase lean body mass (IE muscle mass).
This article finds that bodybuilders (IE people with a lot of lean mass to maintain) require only slightly more protein than a sedentary person of the same weight, while endurance athletes required significantly more.
NeilFann wrote:I'm interested in proper research by people without a product/book to sell.
Solt wrote:NeilFann wrote:I'm interested in proper research by people without a product/book to sell.
This is just anecdotal and thus slightly off topic but I'd like to say that my personal experience with protein supplementation has been highly positive. I started weight training as a skinny teenager after reading "Weight Training for Dummies" to minimal results. I made some gains in what I could lift but hit a wall of fatigue fairly soon and gained no weight. I now realize my diet was terrible in that what I thought was sufficient (1, maybe 2 really big meals a day) wasn't nearly so. I gave up but a few summers later tried everything again but this time I read and believed all the hype on a body building website regarding protein powders and decided to just try. Same equipment, same reference book, same diet and routines just with the protein supplements added? I gained 15 pounds that summer IIRC. A few years later I tried again and gained another 15 though I changed up everything else that time. Still, I would be no where without protein supplements, I am convinced of that.
NeilFann wrote:Anyway, I'm begining to suspect that the best designed and most academic studies I've read come down against the efficacy of protein suppliments BUT there are significant reasons to believe the opposite too.
fooliam wrote:Anecdotally, I weighed 145 pounds the end of my senior year of highschool...by the end of my freshman year of college I weighed around 170 with little change in diet or exercise habits. I just started "filling out" so to speak.
Solt wrote:fooliam wrote:Anecdotally, I weighed 145 pounds the end of my senior year of highschool...by the end of my freshman year of college I weighed around 170 with little change in diet or exercise habits. I just started "filling out" so to speak.
That's a big lifestyle change to undergo without any changes in diet and exercise.
Comparison of protein intakes on strength, body composition and hormonal changes were examined in 23 experienced collegiate strength/power athletes participating in a 12-week resistance training program. Subjects were stratified into three groups depending upon their daily consumption of protein; below recommended levels (BL; 1.0 – 1.4 g·kg-1·day-1; n = , recommended levels (RL; 1.6 – 1.8 g·kg-1·day-1; n = 7) and above recommended levels (AL; > 2.0 g·kg-1·day-1; n = . Subjects were assessed for strength [one-repetition maximum (1-RM) bench press and squat] and body composition. Resting blood samples were analyzed for total testosterone, cortisol, growth hormone, and insulin-like growth factor. No differences were seen in energy intake (3,171 ± 577 kcal) between the groups, and the energy intake for all groups were also below the recommended levels for strength/power athletes. No significant changes were seen in body mass, lean body mass or fat mass in any group. Significant improvements in 1-RM bench press and 1-RM squat were seen in all three groups, however no differences between the groups were observed. Subjects in AL experienced a 22% and 42% greater change in Δ 1-RM squat and Δ 1-RM bench press than subjects in RL, however these differences were not significant. No significant changes were seen in any of the resting hormonal concentrations. The results of this study do not provide support for protein intakes greater than recommended levels in collegiate strength/power athletes for body composition improvements, or alterations in resting hormonal concentrations.
nightbird wrote:EVERYBODY who's interested in sports nutrition should read Brad Pilon's works, IMHO.
nightbird wrote:For building an appreciable ammount of body mass, overall calories are far more important - people seem to forget that
Victoria Maddison wrote:nightbird wrote:EVERYBODY who's interested in sports nutrition should read Brad Pilon's works, IMHO.
Pilon's book is a poor survey of the scientific literature with badly drawn conclusions. I'd advise against it.
nightbird wrote:Could you elaborate on that?
Sports nutrition research suggests that endurance athletes need 1.2 - 1.4g protein/kg body mass/day and strength-trained athletes may require up to 1.7g protein/kg/day, although this is far above the RDA for protein of .8g/kg body mass/day.
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