• Protein, how much to eat per meal? A systematic review in maximizing the muscle protein synthetic response in resistance-trained athletes

      Jawadwala, Rehana; Van Vliet, Stephan (University of Chester, 2011-10)
      It is common practice in strength sports to spread out nutrient intake, and more specifically protein, into small amounts during the day with the belief that this is not only optimal but absolutely necessary in order to render in optimal response in terms of protein utilization and growth. Moreover this notion mainly stems from the believe that only a limited amount of protein (20 – 30 g-1) can be utilized per meal. OBJECTIVE: To evaluate existing evidence into the amount of protein that might optimize the muscle protein synthetic response (MPS) in the post prandial period. DESIGN: Systematic review of randomized controlled trials (RTCs). SUBJECTS: ‘Healthy’ adult subjects (18 – 64 years of age) either after an acute bout of resistance training and/or systematic involvement in resistance training (minimum of 3 days/week). RESULTS: 56 studies were identified as primary research, of which 12 were assessed for eligibility. Of these 12 studies, 3 met the predetermined inclusion criteria. Synthesis of the evidence showed included studies varied considerably in terms of study design, quality and outcomes, yet showed no evidence that only a limited amount of protein can be utilized per meal. CONCLUSION: At this point there is no evidence that only 20 – 30 g-1 of protein per meal can be utilized per meal by resistance trained athletes while on the other hand there is, at best, very minor evidence that more than these amounts ( ~ 40 g-1) might stimulate MPS to a greater degree. Further studies should focus on comparing various amounts of protein using ‘realistic’ administration of nutrients as well as with the usage of ‘realistic’ training protocols.
    • What are the maximum protein requirements of strength athletes? A systematic review

      Fallows, Stephen; Foster, Brandon (University of Chester, 2008-09-30)
      Protein intakes above the recommended dietary allowance (RDA) for adult males have been suggested to be essential in accreting lean body mass, particularly in active individuals. Though, what is the maximum protein requirement of strength athletes in order to maximise their performance. A systematic review was conducted on all primary literature to establish the maximum protein requirements of strength athletes. A comprehensive search strategy involving searches of six electronic databases and ‘grey’ literature were conducted. The search was restricted to studies published after 1986 to the present day. All primary research literature that presented the effect of total dietary protein intake on lean body mass was included. Studies that met the inclusion criteria were assessed for methodological quality using the Downs and Black checklist. 4 studies were identified that met the inclusion criteria, although only 3 studies met the quality assessment criteria; two randomised trials and one non-randomised trial. Statistically non-significant trends (p>0.05) deriving from muscle mass measurements, determined that the maximum protein requirement for strength athletes to be a moderate quantity of 1.4g/kg Bw/day. Similar results were shown in all three studies. There is a sparsity of evidence and an inconsistency in the methodological designs between trials, regarding what the maximum protein requirement of strength athletes to be. Yet, it is likely to be a moderate protein intake, rather than a high protein intake.