"Ounce-equivalents" in the Protein Foods Group: Benefits of Quality
Condition: Protein Metabolism
Study type: Interventional

Summary: 
      The investigators will examine the effects of a given amount of a protein food source such as
      pork, mixed nuts, and tofu on anabolic response at the whole body and muscle levels in young,
      healthy adults.
    

Detailed description: 
      Over the past 35 years the United States Department of Agriculture (USDA) Dietary Guidelines
      for Americans (DGAs) has sought to translate recommendations on nutrient requirements (i.e.,
      Recommended Dietary Allowances) from the Food and Nutrition Board of the Institute of
      Medicine (IOM) into practical nutritional advice for the American public. Although the DGAs
      are intended to incorporate additional scientific evidence, the lack of appropriate focus on
      protein nutrition is a major shortcoming of the DGAs. Not only is the amount of protein not a
      major focus, absolutely no mention is made of protein quality. In general, animal proteins
      have much higher the Digestible Indispensable Amino Acid Scores (DIAASs) than plant proteins,
      often by as much as two fold. Account has not been taken of DIAAS, or even the general
      concept of the importance of the amount and profile of essential amino acids in individual
      proteins, in formulation of MyPlate or the scientific report of the DGAs Committee. This is
      because a classification does not apply to most plant proteins, despite the fact that in the
      IOM report stating the Recommended Dietary Allowance for protein it is specified that this
      refers to "high quality protein. To help the consumer meet protein needs while achieving the
      goal of varied protein food sources, the DGAs Committee published "ounce equivalents" in the
      protein foods group. It is stated among other equivalents cited, that 1 ounce (oz.) of meat
      is equivalent to 1 tablespoon (Tbsp.) of peanut butter and 1/4 cup (0.5 ounces) of cooked
      kidney beans. But are they really equivalent? This indicates that the "ounce equivalents" of
      protein foods in MyPlate are not equivalent in any parameter that might be used to assess
      nutritional benefit, and demonstrates that the bias against animal proteins is in the Dietary
      Guidelines. The misrepresentation of the equivalencies of various food sources of protein in
      MyPlate raises the question of the process by which this occurred, and how can the process be
      influenced to more accurately reflect that high quality of animal proteins? Therefore,
      developing convincing data to correct the MyPlate "ounce equivalents" of protein foods is an
      achievable goal. In general, dietary protein intake serves many physiological roles, but the
      most prominent is the maintenance or gain of body protein. This is accomplished by
      stimulation of protein synthesis, the inhibition of protein breakdown, or a combination.
      Thus, the functional response to consumption of a given amount of a protein food source is
      best assessed by quantifying the rates of protein synthesis and breakdown at the whole body
      level as well as at the muscle level in order to calculate the anabolic response. The
      investigators propose to make these measurements in response to intake of "equivalent
      "(according to MyPlate) amounts of pork, mixed nuts and tofu. Moreover, the functional
      responses to these varied sources of protein we will examine coincide with the predictions
      from the USDA nutrient data base, and calculation of the DIAAS will provide needed support to
      redefine "ounce equivalents" of protein food sources according to those data bases for all
      animal and plant sources of protein.
    

Intervention name(s): Pork intake; Mixed nuts intake; Tofu intake
Intervention type(s): Dietary Supplement; Dietary Supplement; Dietary Supplement
Intervention description(s): Each participant will consume 2 ounces of cooked lean pork.; Each participant will consume 1 ounce of mixed nuts.; Each participant will consume 2 ounces of tofu.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Basic Science