Food ingestion in an upright sitting position increases postprandial amino acid availability when compared with food ingestion in a lying down position

• Published in: Applied physiology, nutrition, and metabolism Vol. 42; no. 7; pp. 738 - 743
• Main Authors: Holwerda, Andrew M, Lenaerts, Kaatje, Bierau, Jörgen, Wodzig, Will K.W.H, van Loon, Luc J.C
• Format: Journal Article
• Language: English
• Published: Canada NRC Research Press 01.07.2017; Canadian Science Publishing NRC Research Press
• Subjects: Acetaminophen - blood; acides aminés; Adult; Amino acids; Amino Acids - blood; Amino Acids - pharmacokinetics; Animals; Body Mass Index; body position; Carbon Isotopes - blood; Comparative analysis; Cross-Over Studies; Diet; Dietary protein; Dietary Proteins - administration & dosage; Dietary Proteins - blood; Digestion; Eating; Gastric Emptying; Health aspects; Humans; Ingestion; leucine; Leucine - blood; Male; Milk - chemistry; Muscle Proteins - metabolism; Phenylalanine - blood; position corporelle; postprandial; Postprandial Period; Posture; Posture - physiology; Prone Position - physiology; protein; Protein synthesis; protéines; vidange gastrique; leucine; postprandial; position corporelle; protéines; vidange gastrique; amino acids; protein; digestion; acides aminés; body position; gastric emptying
• ISSN: 1715-5312; 1715-5320
• DOI: 10.1139/apnm-2016-0522

Dietary protein digestion and absorption kinetics determine the postprandial increase in muscle protein synthesis. We recently demonstrated that body position during feeding can modulate the postprandial rise in plasma amino acid availability. Here we investigated whether protein ingestion in an upright sitting body position accelerates gastric emptying and improves dietary protein digestion and subsequent amino acid absorption compared with feeding in a supine lying body position. In a crossover design, 8 young males (age, 26 ± 1 years; body mass index, 24.0 ± 0.9 kg·m −2 ) ingested 20 g intrinsically l -[1- 13 C]-phenylalanine–labeled milk protein plus 1.5 g paracetamol while sitting in an upright position or lying down in a supine position. Blood samples were collected frequently during a 5-h postprandial period. Gastric emptying rates and dietary protein digestion and absorption were assessed using plasma paracetamol and amino acid concentrations as well as plasma l -[1- 13 C]-phenylalanine enrichments. Peak plasma leucine concentrations were higher when protein was ingested in an upright sitting versus lying position (213 ± 15 vs 193 ± 12 μmol·L −1 , P < 0.05), which was accompanied by a trend for a greater overall leucine response (13 989 ± 720 vs 11 875 ± 1073 AU, respectively; P = 0.05). Peak plasma paracetamol concentrations were higher in the sitting versus lying treatment (11.6 ± 0.5 vs 9.3 ± 0.6 mg·L −1 , P < 0.05). Protein ingestion in an upright sitting position accelerates gastric emptying and increases the postprandial rise in plasma amino acid availability by increasing protein digestion and amino acid absorption rates. Therefore, feeding in an upright body position as opposed to a lying position is an important prerequisite to allow proper postprandial muscle protein accretion.