Sustained Meat and Alternative Intake (PRotEin DIet SatisfacTION Trial 4) (PREDITION)
Condition: Well-being
Study type: Interventional

Summary: 
      Introduction The trend of flexitarian eating patterns is on the rise, with young adults
      amongst the biggest adopters claiming health and environmental reasons to reduce red meat
      intake. Nutrient dense meat and animal products are often the lynchpin of these diets, even
      when consumed only occasionally and in moderate amounts. Red meat provides forms and
      concentrations of essential proteins, lipids, and micronutrients that are scarce in
      exclusively vegetarian regimens. The aim of this investigation is to consider the effects of
      moderate consumption of lean red meat as part of an otherwise vegetarian balanced diet and
      its impact on biomarkers of sustained health and wellbeing.

      Methods and analyses A cohort of healthy, young (20-34 years) male and female participants
      will take part in two-arm parallel, randomised-controlled trial for a duration of 12 weeks,
      with a 3-month post follow-up. The trial will commence with a two-week assessment period
      followed by allocation to the intervention arms. The intervention will include the
      consumption of red meat or meat-alternatives three times per week for 10 weeks. Blood samples
      of the participants will be measured for changes in erythrocyte fatty acid distribution,
      circulating amino acids, neurotransmitters, markers of mineral status and inflammatory
      markers. Questionnaires to assess wellbeing and mental health will be undertaken every two
      weeks. Body composition, physical function test, blood measurements will be assessed at
      allocation (t0), week five into the intervention (t5) and post intervention (t10).

      Discussion To our knowledge this is the first randomised controlled trial (RCT) investigating
      the overarching health consequences of consuming NZ pasture fed red meat or no meat, as part
      of a healthy diet.

      Ethics and dissemination The trial was approved by the New Zealand Ministry of Health's
      Health and Disability Ethics Committees (20/STH/157).
    

Detailed description: 
      Study Design and Setting The study is a parallel RCT comprising a 2-week pre-intervention
      assessment, a 10-week intervention period and a 22-week post follow up. Participants will all
      eat a balanced plant-based basal diet and be randomised to also consume either red meat
      ('Flexitarian' arm) or a meat substitute ('Vegetarian' arm). The meat will be pasture-raised
      beef and lamb butchered and packaged to our specifications in New Zealand, while the meat
      substitute will be commercially available plant-based products.

      Recognising that there are many interpretations of the terms vegetarian and flexitarian, in
      this study we define vegetarian as ovo-lacto vegetarian and flexitarian as 'a vegetarian diet
      with moderate amounts of red meat'. Both arms can consume eggs and dairy products, but no
      chicken, pork or fish, and no red meat other than that supplied by the researchers.

      The study is designed around pairs of young adult consumers who share meals and are therefore
      likely to engage over the values and challenges of developing a healthy lifestyle. Each
      couple/household unit (see Recruitment) will receive a weekly delivery of a vegetarian meal
      kit containing complete ingredients for cooking 3-4 evening meals. Depending on their
      allocation, the couple will also receive an allotment of frozen red meat or meat-analogue to
      use for preparing 3 additional evening meals. To facilitate cooking and keep the behaviours
      of the arms aligned, we will provide recipe cards, shopping guidance and video instructions.
      All other meals during the week are self-catered and must adhere to study guidelines.

      The quantity of meat will be sufficient to provide 350-500 g cooked weight per person per
      week. This conforms to the latest international recommendations for maximum intake 7 and the
      reported typical frequencies of red meat consumption. The meat alternative will be similar in
      quantity, form and function. It is vegetarian-friendly and serves to balance the total
      protein and fat intake of the arms.

      Changes in objective and self-assessed subjective health variables over time and between arms
      will be investigated. These include physical function, body composition, metabolic health
      biomarkers and psychological wellbeing.
    

Intervention name(s): Non-red meat
Intervention type(s): Other
Intervention description(s): Red meat analogues and alternatives
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Other
Keywords: nutrition; meat; mental health