title: Food ingestion in an upright sitting position increases postprandial amino acid availability when compared with food ingestion in a lying down position.
abstract: 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-[1-13C]-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-[1-13C]-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.
authors.affiliation: a Department of Human Biology and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center+, P.O. Box 616, 6200 MD Maastricht, the Netherlands.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Holwerda
authors.affiliation: b Department of Surgery, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center+, P.O. Box 616, 6200 MD Maastricht, the Netherlands.
authors.forename: Kaatje
authors.initials: K
authors.lastname: Lenaerts
authors.affiliation: c Department of Clinical Genetics, Maastricht University Medical Centre+, P.O. Box 5800, 6202 AZ Maastricht, the Netherlands.
authors.forename: Jörgen
authors.initials: J
authors.lastname: Bierau
authors.affiliation: d Central Diagnostic Laboratory, Maastricht University Medical Centre+, P.O. Box 5800, 6202 AZ Maastricht, the Netherlands.
authors.forename: Will K W H
authors.initials: WKWH
authors.lastname: Wodzig
authors.affiliation: a Department of Human Biology and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Center+, P.O. Box 616, 6200 MD Maastricht, the Netherlands.
authors.forename: Luc J C
authors.initials: LJC
authors.lastname: van Loon
mesh_terms: D000082:Acetaminophen / Q000097:blood; D000328:Adult; D000596:Amino Acids / Q000097:blood* / Q000493:pharmacokinetics; D000818:Animals; D015992:Body Mass Index; D002247:Carbon Isotopes / Q000097:blood; D018592:Cross-Over Studies; D004044:Dietary Proteins / Q000008:administration & dosage / Q000097:blood; D004063:Digestion; D004435:Eating; D005746:Gastric Emptying; D006801:Humans; D007930:Leucine / Q000097:blood; D008297:Male; D008892:Milk / Q000737:chemistry; D009124:Muscle Proteins / Q000378:metabolism; D010649:Phenylalanine / Q000097:blood; D019518:Postprandial Period; D011187:Posture / Q000502:physiology*; D016684:Prone Position / Q000502:physiology*
chemical_list: D000596:Amino Acids; D002247:Carbon Isotopes; D004044:Dietary Proteins; D009124:Muscle Proteins; D000082:Acetaminophen; D010649:Phenylalanine; D007930:Leucine
keywords: acides aminés; amino acids; body position; digestion; gastric emptying; leucine; position corporelle; postprandial; protein; protéines; vidange gastrique