Discussion This review supports our protein spread and change theories

[11] as possible explanations for LY333531 datasheet discrepancies in SB202190 cell line the protein and resistance training literature. In our previous review, we demonstrated that spread and change in study protein intakes may be important factors predicting potential to benefit from increased protein during a weight management intervention. In studies from the present review that showed greater muscular benefits of higher protein, there was a greater % spread between the g/kg/day intake of the higher protein group and control. Additionally, that the higher protein group’s during study g/kg/day protein intake is substantially different than baseline is important. With minimal spreads and changes from habitual intake there are little additional muscular benefits from higher protein interventions. Evidence weighs heavily toward muscular benefits from increased protein [1–10]. Those studies that did not support additional benefits of greater protein still showed that higher protein was as good as an alternative diet [18–20, 22–25]. Protein spread theory Protein type influences the acute anabolic response to see more resistance training [26] and cannot be overlooked as a possible influence on protein spread theory

results. Trained participants in a 10 wk study by Kerksick et al. reached ~2.2 g/kg/day protein from whey/casein protein or whey/amino acid supplementation. Controls consumed 1.56 g/kg/day. Only the whey/casein group gained significantly greater (1.9 kg) lean mass than controls [9]. Hartman et al. had untrained participants supplement with soy protein or milk to achieve a protein intake of 1.65 and 1.8 g/kg/day. Controls consumed 1.65 g/kg/day. The milk group achieved significantly greater increases in type II and I muscle fiber cross-sectional area than controls; soy gains were only significantly greater than controls for type I [6]. These results [6, 9] make more sense in the context of protein spread

theory. That is, Kerksick et al.’s whey/casein group achieved a 12.8% g/kg/day greater spread from controls than did the whey/amino group [9]. Exoribonuclease Hartman et al.’s milk group achieved a 9.1% g/kg/day spread versus controls; the soy group consumed the same as controls [6]. Protein type, whey or soy, did not affect lean mass and strength gains in a study by Candow et al. [2] where there was no spread in protein intake between supplementation groups. Similar to the Kerksick et al. study, lean mass gains, strength gains, and fat loss in participants supplementing with casein protein from Demling et al. were significantly greater than in the whey protein group [5], however the spreads and changes were essentially identical for the casein and whey groups [5]. These authors suggested that perhaps the slow digestion of the casein protein enhanced nitrogen retention as shown previously [27] and this nitrogen retention led to greater muscular gains over time. This explanation was also presented by Kerksick et al. [9].