Amino Acid Profile and Muscle Protein Synthetic Response to Consuming Meat or Plant-based Alternatives
Condition: Healthy
Study type: Interventional

Summary: 
      The purpose of the study is to quantify and compare the serum amino acid profile, and muscle
      protein synthesis rates, in response to consuming isonitrogenous amounts of ground meat (beef
      and pork) or plant-based alternatives -(soy and pea protein-based patties).

      Specific aim 1: Describe the post-prandial amino acid profile in serum in the 3 hours
      following consumption of the following four burger patties, in quantities calculated to
      deliver 20 grams of protein: ground beef, ground pork, Beyond Meat® burger, and tofu burger.

      Specific aim 2: Compare the ability of these four different foods to activate mTORC1 and
      protein synthesis in muscle.
    

Detailed description: 
      Study design:

      The first visit will be a brief meeting conducted over Zoom with one of the investigators
      (Karine Schaal), who will go over the study details with the volunteer, answer their
      questions, and obtain informed consent. Subjects will sign the informed consent
      electronically, using DocuSign. Subjects will be given a copy of their signed informed
      consent form. A paper copy of the consent form will be kept in a locked file cabinet in the
      office of the principal investigator.

      Study volunteers will come to the CTSC Clinical Research Center (CCRC) on four separate
      occasions. The CCRC is located in the Cypress Building adjacent to the UC Davis Medical
      Center (2221 Stockton Blvd, Suite D, Sacramento CA 95817).

      The four study visits will be test visits scheduled over a two week period (i.e. twice per
      week for 2 weeks), at the same time in the morning following and overnight (> 12 hour) fast.
      They will be asked to refrain from vigorous exercise, caffeine, nicotine and alcohol for 24
      hours prior to each visit. Female volunteers will be asked to schedule their study visits
      within the first two weeks of their menstrual cycle (starting on the first day of menstrual
      bleeding), in order to control for ovarian hormone fluctuations which may impact digestion
      and metabolism.

      Upon arrival to the CCRC on the first test visit, each volunteer's height and weight will be
      measured.

      I. Baseline blood draw. Subjects will then be placed in individual testing rooms, equipped
      with a reclining phlebotomy armchair. A registered nurse or nurse practitioner will insert a
      22G catheter in a forearm vein and an initial 3.5 mL baseline blood sample will be collected.

      II. Test meal.

      After the baseline blood sample is collected, subjects will consume one of the following four
      burgers in isonitrogenous amounts to deliver 20 g of protein:

        -  106g ground beef patty (85% lean + 15% fat)

        -  118g ground pork (72.5% lean + 27.5% fat)

        -  113g Beyond Meat® patty

        -  113g tofu patty

      Each food will be weighed before cooking. The beef, pork and Beyond® burgers will be grilled
      on an indoor electric grill until internal temperature reaches 165°F to comply with the USDA
      Recommendations for Food Safety (beef and pork, minimum 160°F) and manufacturer instructions
      (Beyond Meat®). Tofu burgers are pre-cooked and will be warmed by grilling for 2 minutes, per
      manufacturer recommendations. The internal temperature of the burgers will be monitored using
      a meat thermometer. The burgers will be served to the volunteers as soon as they are finished
      cooking.

      Subjects will be asked to consume each patty without buns or condiments within a 10 minute
      period, and instructed to chew thoroughly. They will also be asked to drink a 6 ounce glass
      of water with the meal.

      III. Postprandial blood draws.

      Following consumption of the test meal, the participants will remain at the research site, in
      their individual testing room, for another 3 hours, sitting quietly - they may bring books or
      electronic devices to pass the time. Five more blood samples of 3.5 mL each will be obtained
      at 30, 60, 90, 120 and 180 minutes after the test meal, totaling six blood draws of 3.5mL per
      visit (21mL per visit), and 84 mL of blood drawn in total for each subject completing the
      entire study.

      Blood will be collected in 3.5 mL serum separating tubes. Approximately 50 microliters of
      whole-blood will be used to measure blood glucose within 5 minutes of the draw. The rest will
      be allowed to clot for 1hr before centrifugation at 1000 x g for 10 minutes.The serum will be
      frozen and kept at -80°C until processed. 100 microliters of each serum sample will be used
      for determining amino acid concentrations by high performance liquid chromatography (HPLC) at
      the UC Davis Proteomics Core. Another 100 microliters will be used to measure insulin
      concentrations via enzyme-linked immunoassay. The rest of the serum will be used for
      developing the mTORC1 bioassay.

      The order in which subjects receive each test meal will be randomized to avoid any order
      effect, and at least a two-day washout period will be given between visits.
    

Intervention name(s): Ground beef; Ground pork; Tofu; Beyond Meat
Intervention type(s): Other; Other; Other; Other
Intervention description(s): Subjects will consume a 106g patty of cooked ground beef.; Subjects will consume a 118g patty of cooked ground pork; Subjects will consume a 113g patty of cooked tofu; Subjects will consume a 113g BeyondMeat patty.
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Basic Science
Keywords: Meat protein; Plant protein; Muscle protein synthesis