Plasma Amino Acid Appearance and Status of Appetite Following a Single Meal of Red Meat or a Plant-Based Meat Analog: A Randomized Crossover Clinical Trial

Abstract

Background: Red meat is a nutrient-dense food and a dietary staple. A new generation of plant-based meat analogs (PBMAs) have been designed to mimic the experience of eating meat, but there is limited evidence about their digestive efficacy and nutritional quality. Objectives: We compared the postprandial digestive response of a single meal containing meat commercially raised in New Zealand, including lamb, on-farm pasture-raised beef (Pasture), or grain-finished beef (Grain) with a PBMA (Beyond Burger; Beyond Meat) sold through consumer retail. The primary outcome was the appearance of amino acids in plasma. Secondary outcomes included glucose and insulin, appetite assessment, and anthropometry. Methods: Thirty healthy men (20-34 y) participated in a double-blinded randomized crossover trial. Each consumed 1 of the 4 test meals on 4 occasions separated by a washout period of at least 1 wk, following an overnight fast. The meal was a burrito-style wrap containing meat or PBMAs, vegetables, salsa, and seasonings in a flour tortilla. The amount of Pasture, Grain, Lamb, or BB was 220 g raw (∼160 g cooked). Venous blood samples were collected over 4 h. Appetite and hunger status was scored with visual analog scales. Results: Pre-meal amino acid concentrations in plasma did not differ by group (P > 0.9), although several nonessential amino acids differed strongly according to participant BMI. Postprandial amino acids peaked at 2-3 h in all groups. The BB meal produced significantly lower plasma concentrations of total, essential, branched-chain, and non-proteogenic amino acids than the Lamb, Pasture, or Grain meals, based on AUC. There were no significant differences between meal groups in scores for hunger, fullness, or cravings. Conclusions: Red meat meals exhibited greater bioavailability of amino acids compared with the PBMA (BB). Pasture versus Grain origins of the beef had little influence on participants' responses.