Acute Meat and Alternative Intake (PRotEin DIet SatisfacTION Trial 3)
Acute Meat and Alternative Intake (PRotEin DIet SatisfacTION Trial 3)
Introduction: Protein rich foods that are alternatives to farm-grown meat have received
 considerable consumer attention. Whilst meat alternatives were once niche food products aimed
 at vegetarians, they are increasingly marketed to omnivores and "flexitarians", thus
 contributing to a trend for reductions in red meat intakes [1]. Studies to date have
 addressed the environmental benefit, plus consumer perceptions and acceptability of meat
 alternatives [2, 3, 4], yet there is surprisingly a paucity of data compared the nutritional
 and digestive differences to meat. The aim of this trial is to compare the digestive
 consequences of pasture-fed and grain-finished, beef versus a plant-based meat analogue
 blinded meal.

 Methods and analyses: Healthy, young (20-34 y) participants will be asked to consume three
 separate meals in a crossover, blinded investigation followed by five hours of blood testing
 and questionnaires to assess the digestive consequences of meat and a plant-based meat
 analogue. The three meals will include either pasture-fed, or grain-finished, or laboratory
 based protein alternative as a mixed meal, in random order, separated by one week minimum.
 Plasma samples will be assessed amino acid content, neurotransmitter proteins, chylomicron
 fatty acid distribution and general health indices.

 Ethics and dissemination: The trial has been granted ethical approval by the Ministry of
 Health, Health and Disability Ethics Committee (Ref: 19/STH/226). All results originating
 from this study will be submitted for publication in scientific journals and presented at
 meetings.
Introduction: Red meat consumption contributes important nutrients to the diet, including
 essential amino acids, long chain and complex lipids, vitamins (including B12) and minerals
 (including iron and zinc) [5]. While supplying these important nutrients, red meat may
 contain components which may negate optimal health such as the saturated fat content and
 nitrates, that are added during processing [5]. The degree to which red meat affects health
 is likely related to its inherent nutritional profile, the quantity consumed and any
 processing (e.g. nitrates or cooking techniques). Regardless, the simple notion of a complex
 whole-food containing single nutrients which are 'good' or 'bad' for health is now considered
 overly simplistic [6]. For example, to reduce heart disease, nutritional guidelines now
 suggest an increase in polyunsaturated fats at the expense of saturated fat, rather than a
 complete reduction of all fats [6].

 Alongside the controversy over the health consequences of red meat, recent attention has
 focused on the possibility of using "plant-based" proteins as an alternative to red meat
 consumption. The search for meat alternatives has resulted in a sharp increase in the
 production of novel "plant-based" meat analogues that have been designed to replicate the
 taste and eating experience of red-meat. To date there are very few studies addressing the
 nutritional differences between traditional red meat and plant-based meat analogues, and the
 nutritional differences that arise due to different production systems. Given the nutritional
 composition of red meat is likely to be influenced by the farming and feeding practices of
 the animals, production procedures and end-user cooking techniques [7], these differences
 need to be accounted for in the research design and application.

 Aims: To investigate the digestive responses to an acute intake of pasture-fed beef,
 grain-finished beef, lamb and a plant based meat-analogue consumed as a component of a mixed
 meal. This study is part of a larger programme to understand the nutritional implications of
 consuming New Zealand, pasture-fed red meat as part of a balanced diet.

 Study Design and Setting: The study is designed as randomised cross-over trial to capture
 biological difference in postprandial nutrient dynamics. Research subjects will act as their
 own controls and will consume each meal (pasture raised, grain-fed beef, lamb and a meat
 alternative meal) on a separate occasion in random order. The study compares exemplars of
 pasture-fed New Zealand beef, grain-finished New Zealand beef, lamb and a meat analogue. The
 plant-based meat analogue has been selected on the basis of its macronutrient profile
 (protein and fat) and appearance in order to that best matches that of meat.

 The digestion and metabolism of key nutrients in beef will be measured immediately after the
 ingestion of a single meal. This experimental setting will also be used to examine some
 subjective qualities of the meal experience, such as satisfaction score (i.e., liking,
 satisfaction, enjoyment, satiety, appetite) and gastrointestinal score (i.e., comfort,
 fullness, bloating, rumbling, flatulence, faecal urgency, diarrhoea).
Inclusion Criteria:

 -  All participants will be required to be omnivores willing to consume both red meat and
 plant-base alternatives for the purposes of the trial.

 Exclusion Criteria:

 -  Those with chronic health conditions, hyperlipidaemia, obesity (BMI ≥ 30), use of
 medications (except occasional use of NSAIDs and antihistamines), history of anosmia
 and ageusia (issues with taste and smell), current dieting or disordered eating
 pattern and smoking tobacco or recreational drugs will be excluded from participating.

 -  Participants will be asked to complete an on-line screening which will include the
 Three-factor Eating Questionnaire-R18 (TFEQ) and a health survey. Participants with a
 TFEQ score greater than 75% will be excluded from participating on the basis their
 perception of food is potentially influenced by underlying psychological issues