An acute, blinded, randomised cross-over design intervention to compare beef, lamb and a meat analogue on digestive, metabolic and nutritional outcomes

Background: Plant-based analogues and substitutes for animal meat are receiving considerable attention within academia and the popular press. Once a niche product aimed at vegetarians, they are increasingly promoted to omnivores and meat-moderating “flexitarians”. Proponents view these new foods as a means of reducing livestock production and improving the environment, whilst industry sees opportunity to repurpose traditional and novel crops into high-value ingredients. To date, most research on meat alternatives has focused on public perception, processing technologies, hedonics and the consumer acceptability issues that underpin product development. There have been surprisingly few investigations into the nutritional, health and well-being consequences of consuming meat analogues over the short- or long term. The aim of our current trial is to consider the digestion, absorption and utilisation of a meat-analogue meal in Millennial consumers and compare that to matched meals featuring pasture-raised or grain-finished beef. Methods: A cohort of healthy, young (20-34 yrs) male participants will consume a single meal on three occasions in a treatment-crossover, blinded investigation. Each instance will be followed by five hours of repeated venous blood collection to assess the digestive and metabolic effects of the meal. The three meals include a popular commercial meat analogue comprising pea, bean and rice extracts plus plant fats and cellulose, or a beef patty from pasture-raised cattle or grain-fed cattle. Samples of the participants’ blood plasma will be measured for changes in amino acid profile, neurotransmitter proteins, chylomicron fatty acid distribution and biomarkers of general health. Discussion: To our knowledge this is the first randomised controlled trial (RCT) comparing the acute nutritional effects of iso-caloric, blinded meals containing a plant-based meat analogue or pasture-fed- or grain-finished beef. The study provides proof of principle for only the effects of a single meal. Future work will translate these insights into longer-term, lifestyle interventions. Trial Registration This study, registered as Universal trial number: U1111-1244-9426. ClinicalTrials.gov: NCT04545398 will be carried out under the auspices of The University of Auckland. The trial has been granted ethical approval by the Ministry of Health, Health and Disability Ethics Committee (Ref: 19/STH/226). Date and version: 9/05/22, version 1