Those are good questions.
However there is a few other studies that need consideration in regards to the 1g per pound recommendation.
Ingested protein dose response of muscle and albumin protein synthesis after resistance exercise in young men.
Abstract
BACKGROUND: The anabolic effect of resistance exercise is enhanced by the provision of dietary protein.
OBJECTIVES: We aimed to determine the ingested protein dose response of muscle (MPS) and albumin protein synthesis (APS) after resistance exercise. In addition, we measured the phosphorylation of candidate signaling proteins thought to regulate acute changes in MPS.
DESIGN: Six healthy young men reported to the laboratory on 5 separate occasions to perform an intense bout of leg-based resistance exercise. After exercise, participants consumed, in a randomized order, drinks containing 0, 5, 10, 20, or 40 g whole egg protein. Protein synthesis and whole-body leucine oxidation were measured over 4 h after exercise by a primed constant infusion of [1-(13)C]leucine.
RESULTS: MPS displayed a dose response to dietary protein ingestion and was maximally stimulated at 20 g. The phosphorylation of ribosomal protein S6 kinase (Thr(389)), ribosomal protein S6 (Ser(240/244)), and the epsilon-subunit of eukaryotic initiation factor 2B (Ser(539)) were unaffected by protein ingestion. APS increased in a dose-dependent manner and also reached a plateau at 20 g ingested protein. Leucine oxidation was significantly increased after 20 and 40 g protein were ingested.
CONCLUSIONS:
Ingestion of 20 g intact protein is sufficient to maximally stimulate MPS and APS after resistance exercise. Phosphorylation of candidate signaling proteins was not enhanced with any dose of protein ingested, which suggested that the stimulation of MPS after resistance exercise may be related to amino acid availability. Finally, dietary protein consumed after exercise in excess of the rate at which it can be incorporated into tissue protein stimulates irreversible oxidation.
and
A moderate serving of high-quality protein maximally stimulates skeletal muscle protein synthesis in young and elderly subjects.
Abstract
Ingestion of sufficient dietary protein is a fundamental prerequisite for muscle protein synthesis and maintenance of muscle mass and function. Elderly people are often at increased risk for protein-energy malnutrition, sarcopenia, and a diminished quality of life. This study sought to compare changes in muscle protein synthesis and anabolic efficiency in response to a single moderate serving (113 g; 220 kcal; 30 g protein) or large serving (340 g; 660 kcal; 90 g protein) of 90% lean beef. Venous blood and vastus lateralis muscle biopsy samples were obtained during a primed, constant infusion (0.08 mumol/kg/min) of L-[ring-(13)C(6)] phenylalanine in healthy young (n=17; 34+/-3 years) and elderly (n=17; 68+/-2 years) individuals. Mixed muscle fractional synthesis rate was calculated during a 3-hour postabsorptive period and for 5 hours after meal ingestion. Data were analyzed using a two-way repeated measures analysis of variance with Tukey's pairwise comparisons. A 113-g serving of lean beef increased muscle protein synthesis by approximately 50% in both young and older volunteers. Despite a threefold increase in protein and energy content, there was no further increase in protein synthesis after ingestion of 340 g lean beef in either age group.
Ingestion of more than 30 g protein in a single meal does not further enhance the stimulation of muscle protein synthesis in young and elderly.basically they both show that 20-30g of protein maximally stimulates protein synthesis, and that any more than this is burned off as energy. Also from other studies done on constant infusion of bcaa, we know there is a refractory period involved that limits the frequency of meals.
so in theory - the most efficient intake of protein in terms of maximal synthesis and absorbsion is 20g of whey every 2 hours. so over the course of the day this amounts to around 140g a day. that's assuming you are awake for 14 hours a day. if you want to waken up throughout the night and drink shakes all night as well its 240g.
i don't think its practical for most, but interesting none the less.
regarding your question of maximal fat loss - protein sparring modified fasts have been scientifically proven to reduced fat the fastest. they are not easy however. i have tried it. i lost just over 50lbs i think over 4 months last year using this method, and i even included pig out weekends where i would eat anything i wanted ( which i did). i wasn't working out during this time, i did however do pushups and bodyweight squats a few times a week. This was also while i was working a physically tiring job and on my feet all day.
i was tired a lot, but not as bad as you would think, but the weight rebound was very fast though
in regard to muscle gain - once your protein requirements are met, any extra calories from fat or carbs will produce muscle gain ( assuming your exercise is up to par).
Effects of high-calorie supplements on body composition and muscular strength following resistance training.
Abstract
BACKGROUND: Seventy-three healthy, male subjects randomly divided into 3 groups participated in a study to determine the effects of 2 high-calorie nutritional supplements on body composition, body segment circumferences, and muscular strength following a resistance-training (RT) program.
METHODS: In addition to their normal diets group 1 (CHO/PRO; n=26) consumed a 8.4 Mj x day(-1) (2010 kcal) high calorie, high protein supplement containing 356 g carbohydrate and 106 g protein. Group 2 (CHO; n=25) consumed a carbohydrate supplement that was isocaloric with CHO/PRO. Group 3 (CTRL; n=22) received no supplement and served as a control. All subjects were placed on a 4-day x week(-1) RT program for 8 weeks.
RESULTS: Dietary analysis revealed no significant differences in total energy consumption or nutrients at any time in the non-supplemented diets of the 3 groups. Significant (p= or <0.05) increases in body mass (BM) and fat-free mass (FFM) were observed in CHO/PRO and CHO compared to CTRL. Mean (+/- SD) increases in BM were 3.1+/-3.1 kg and 3.1+/-2.2 kg, respectively.
Fat-free mass significantly (p= or <0.05) increased 2.9+/-3.4 kg in CHO/PRO and 3.4+/-2.5 kg in CHO. Muscular strength, as measured by a one-repetition maximum in the bench press, leg press, and lat-pull down increased significantly (p= or <0.05) in all groups. No significant differences in strength measures were observed among groups following training.
CONCLUSIONS: Results indicate that high-calorie supplements are effective in increasing BM and FFM when combined with RT.
However, once individual protein requirements are met, energy content of the diet has the largest effect on body composition. extra carbs and or fats may be better than more protein due to their ability to provide efficient energy. Carbs also has the advantage to stimulate excess insulin with has an effect on reducing protein breakdown rates.
regarding calories - small increases in calories are advisable rather than pig out/ bulking type diets. this works both for fat loss/muscle retention and muscle gain/minimum fat gain. 500cals extra a day until your strength stalls and or the scales do not change, then increase again, etc etc
hopefully this has helped you.
