title: Comparison of daily diets containing 400 kcal (1.67 MJ) of either protein or glucose, and their effects on the response to subsequent total fasting in obese subjects.
abstract: Eleven obese subjects (body mass index, 41.3 kg/m2) were examined to determine their metabolic and acid-base responses during two hypoenergetic diets, and the diets' influence on subsequent responses to prolonged total fasting. Subjects were first treated for 2 wk with 400-kcal/d (1.67-MJ/d) diets of either protein (13.2 g nitrogen, 23 mmol potassium) or glucose with 16 mmol potassium chloride and a multivitamin supplement. Mild acidosis developed during the protein diet as well as greater excretions of urinary ammonium and urea N, a greater degree of ketosis, and significantly better N balance (-42.7 vs -80.4 g, p less than 0.05) than during the glucose diet. The subsequent fast was associated with greater negative N balance after protein (-129 vs 83 g), mainly as urea N, but despite similar ketosis there was a greater acidosis after glucose and greater ammonium N excretion and cumulative K losses. These data support the concept of a labile N pool, depleted during a glucose diet and resulting in a decreased loss with the subsequent fast. We suggest a role for K depletion in augmenting fasting ammonium excretion.
authors: McGill Nutrition and Food Science Centre, Royal Victoria Hospital, Montreal, Quebec, Canada.
authors: R
authors: R
authors: Gougeon-Reyburn
authors: L A
authors: LA
authors: Leiter
authors: J F
authors: JF
authors: Yale
authors: E B
authors: EB
authors: Marliss
mesh_terms: D000136:Acid-Base Equilibrium; D000138:Acidosis / Q000378:metabolism; D000328:Adult; D000596:Amino Acids / Q000378:metabolism; D001786:Blood Glucose / Q000032:analysis; D004040:Dietary Carbohydrates / Q000008:administration & dosage* / Q000494:pharmacology; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000494:pharmacology; D004573:Electrolytes / Q000378:metabolism; D002149:Energy Intake; D005215:Fasting; D005260:Female; D005947:Glucose / Q000008:administration & dosage* / Q000494:pharmacology; D006801:Humans; D007662:Ketosis / Q000378:metabolism; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D009584:Nitrogen / Q000378:metabolism; D009765:Obesity / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism
chemical_list: D000596:Amino Acids; D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004044:Dietary Proteins; D004573:Electrolytes; D005947:Glucose; D009584:Nitrogen; D011188:Potassium