Essential Amino Acids and Protein Kinetics During Caloric Deprivation
Condition: Muscle Protein Synthesis; Whole-body Protein Balance
Study type: Interventional

Summary: 
      The amount of essential amino acids (EAA) necessary to maximally stimulate muscle protein
      synthesis and optimize whole-body net protein balance during caloric deprivation has not been
      determined. This study will address that gap in knowledge by examining the resting and
      post-exercise muscle and whole-body protein kinetic responses to ingesting varying amounts of
      EAA after a 5 day period of negative energy balance. This study will provide the initial
      evidence to support the development of a recovery-based food product for military combat
      rations.
    

Detailed description: 
      Short-term negative energy balance downregulates muscle protein synthesis and upregulates
      whole-body proteolysis and amino acid (AA) oxidation, thereby increasing nitrogen excretion
      and exacerbating whole-body and skeletal muscle protein loss. Consumption of quality proteins
      high in essential amino acid (EAA) content may attenuate protein loss during energy deficit
      by restoring whole-body and skeletal muscle anabolic potential to that observed in a
      eucaloric state. During energy balance, muscle protein synthesis appears to be maximally
      stimulated after consuming 15 g of EAA at rest and after conventional resistance-type
      exercise. In response to a short-term energy deficit that downregulated basal muscle protein
      synthesis by as much as 27%, consuming 15 g (~7.5 g EAA) and 30 g (~15 g EAA) of whey protein
      after a bout of resistance exercise restored muscle protein synthesis rates to resting,
      fasted rates observed in the eucaloric state in a dose dependent manner. The effect of EAA
      intakes above 15 g on resting and post-exercise muscle protein synthesis and the whole-body
      protein anabolic response during acute energy deficit has not been determined. This study
      will assess resting and post-resistance exercise whole-body and skeletal muscle protein
      synthesis responses to across a spectrum of EAA intakes following a well-controlled,
      short-term (5-d) energy deficit (30% energy deficit). Using a randomized, double-blind,
      cross-over design, 20 resistance trained (≥ 2 d/wk for the past 6 mo) adults will undergo
      two, non-consecutive 5-d energy deficit periods, separated by a 14-d washout period. Resting
      and post-resistance exercise (single leg exercise model) whole-body protein turnover and
      skeletal muscle protein synthesis responses to two different doses of EAA (standard, 0.10
      g/kg vs high, 0.30 g/kg) will be determined the morning after completing the 5-d energy
      deficit. This design will test the hypothesis that higher absolute doses of EAA are required
      to maintain resting and post-exercise anabolic responses during energy deficit.
    

Intervention name(s): Standard EAA; High EAA
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): EAA provided relative to body mass at a standard dose (0.10 g/kg) during energy deprivation; EAA provided relative to body mass at a high dose (0.30 g/kg) during energy deprivation
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Randomized, double-blind, cross-over controlled trial
Masking: Double (Participant, Investigator)
Primary purpose: Basic Science