Dietary carbohydrate-to-fat ratio: influence on whole-body nitrogen retention, substrate utilization, and hormone response in healthy male subjects.
The effect of a high-carbohydrate and a high-fat diet on nitrogen retention, substrate utilization, and serum hormone concentrations was assessed in six healthy male subjects. Both diets were fed at a level estimated to provide maintenance and 75% maintenance energy requirements. Urine and feces were collected and analyzed for N and energy content. Anthropometric measurements; fasting and postprandial oxygen consumption; and serum levels of glucose, triglycerides, and metabolic hormones were measured. The high-fat diet increased N retention at both energy levels with significance reached at maintenance energy intakes (p less than 0.05). The high-fat diet resulted in less weight loss (p less than 0.05) at low energy and a consistently lower respiratory quotient (p less than 0.05), indicative of increased fat oxidation. The N sparing effect of the high-fat diet did not appear to be explained by hormone levels observed but may be substrate mediated.
McCargar
L J
LJ
Nutrition and Metabolism Research Group, University of Alberta, Edmonton, Canada.
Clandinin
M T
MT
Belcastro
A N
AN
Walker
K
K
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight; D002151:Calorimetry; D004040:Dietary Carbohydrates / Q000008:administration & dosage*; D004041:Dietary Fats / Q000008:administration & dosage*; D002149:Energy Intake; D004734:Energy Metabolism; D005243:Feces / Q000032:analysis; D013006:Growth Hormone / Q000097:blood; D006728:Hormones / Q000097:blood*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood; D007328:Insulin / Q000097:blood; D008297:Male; D009584:Nitrogen / Q000378:metabolism* / Q000652:urine; D010101:Oxygen Consumption; D014280:Triglycerides / Q000097:blood; D014284:Triiodothyronine / Q000097:blood
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D006728:Hormones; D007328:Insulin; D014280:Triglycerides; D014284:Triiodothyronine; D013006:Growth Hormone; D009584:Nitrogen; D006854:Hydrocortisone