Dietary carbohydrate and metabolism of ingested protein.
Six normal people were fed a lean beef meal while on a normal diet and after seven days on a very low carbohydrate (greater than 25 g/day) 2000 kcal/day diet. After carbohydrate restriction, the protein-induced rise in branched chain aminoacids was 40-50% greater than the rise after the control diet. Intravenous leucine also produced a 40% greater rise in plasma-leucine after carbohydrate restriction. Three days of fasting exaggerated protein-induced increases in plasma branched-chain aminoacids by 55-77%. Hypocaloric, pure carbohydrate refeeding restored the branched-chain aminoacid responses to normal. Severe carbohydrate restriction thus leads to increased accumulation of plasma branched-chain aminoacids after protein feeding which is at least in part due to reduced utilisation of these aminoacids.
D000328:Adult; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D002417:Cattle; D004032:Diet; D004038:Diet, Reducing; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000378:metabolism*; D005215:Fasting; D005260:Female; D005934:Glucagon / Q000097:blood; D006801:Humans; D007263:Infusions, Parenteral; D007328:Insulin / Q000097:blood; D007532:Isoleucine / Q000097:blood; D007930:Leucine / Q000097:blood / Q000494:pharmacology; D008297:Male; D008460:Meat; D013997:Time Factors; D014633:Valine / Q000097:blood
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D007328:Insulin; D007532:Isoleucine; D005934:Glucagon; D007930:Leucine; D014633:Valine