Effect of a high protein meat diet on muscle and cognitive functions: A randomised controlled dietary intervention trial in healthy men

• Published in: Clinical nutrition (Edinburgh, Scotland) Vol. 30; no. 3; pp. 303 - 311
• Main Authors: Jakobsen, Lene H., Kondrup, Jens, Zellner, Maria, Tetens, Inge, Roth, Erich
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.06.2011; Elsevier
• Subjects: Adolescent; Adult; adverse effects; Amino Acids, Branched-Chain; Amino Acids, Branched-Chain - blood; beverages; Biological and medical sciences; blood; blood sampling; branched chain amino acids; Cognition; Cognitive function; Denmark; Diet; Dietary Proteins; Dietary Proteins - adverse effects; Dietary Proteins - therapeutic use; Feeding. Feeding behavior; food intake; Fundamental and applied biological sciences. Psychology; Gastroenterology and Hepatology; high protein diet; Humans; Male; males; Meat; Meat - adverse effects; men; Muscle function; Muscle, Skeletal; Muscle, Skeletal - physiology; muscles; Nutritional Requirements; phenylalanine; Phenylalanine - blood; physiology; Plasma amino acids; Protein; protein metabolism; protein requirement; proteins; quality of life; Reaction Time; Single-Blind Method; therapeutic use; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Young Adult; Denmark; Muscle function; Cognitive function; Plasma amino acids; Protein; Human; Randomization; Diet; Clinical trial; Metabolic diseases; Cognition; Muscle; Feeding; Meat
• ISSN: 0261-5614; 1532-1983; 1532-1983
• DOI: 10.1016/j.clnu.2010.12.010

Recommendations to use other criteria than N-balance for defining protein requirements have been proposed. However, little evidence to support other measures such as physiological functions is available. To investigate the effects of a usual (UP) versus a high protein (HP) diet on muscle function, cognitive function, quality of life and biochemical regulators of protein metabolism. A randomised intervention study was conducted with 23 healthy males (aged 19–31 yrs). All subjects consumed a Usual Protein (UP) diet (1.5 g protein/kg BW) for a 1-wk run-in period before the intervention period where they were assigned to either a UP or a High Protein (HP) diet (3.0 g protein/kg BW) for 3-wks with controlled intake of food and beverages. Blood and urine samples were taken along with measurements of physiological functions at baseline and at the end of the intervention period. The HP group improved their reaction time significantly compared with the UP group. Branched chain amino acids and phenylalanine in plasma were significantly increased following the HP diet, which may explain the improved reaction time. Healthy young males fed a HP diet improved reaction time. No adverse effects of the HP diet were observed. This trial was registered at www.clinicaltrials.govas NCT00621231.