Clinical Trial: Effects of Dietary Proteins on Hepatic Lipid Metabolism
Study Status: Completed
Recruit Status: Completed
Study Type: Observational
Official Title: Effects of Dietary Proteins on Hepatic Lipid Metabolism
Brief Summary:
Individuals submitted to a high-fat or a high-fructose/sucrose diet develop, over a 6 day-period, several features of the metabolic syndrome, including increased plasma triglycerides, increased intrahepatic lipids, and decreased hepatic insulin sensitivity. It has been recently observed that the increase in intrahepatic lipids observed after a high fat diet is largely prevented when protein intake is concomitantly increased. This suggests that dietary protein protects the liver against some of the deleterious effects of a high fat diet. Mechanisms underlying this effect of protein may include an increased hepatic fat oxidation.
The aims of this study are:
- to evaluate the effects of dietary protein on several major pathways involved in hepatic lipid metabolism ( ketogenesis, lipid oxidation, de novo lipogenesis, VLDL-triglyceride secretion
- to determine whether the decrease in intra-hepatic lipids observed when dietary protein intake is increased are to be attributed to acute or long-term effects of proteins
Detailed Summary:
This research project include three sub-studies of healthy, normal weight, young males.
Sub-study A1: The effects of acute and chronic increase in protein intake on whole body and hepatic lipid metabolism will be studied in healthy males. Two groups of 7 subjects will be recruited.
One group will be studied on three occasions, during which their metabolism will be evaluated in basal, post-absorptive conditions and over 6 hours after ingestion of mixed meal containing carbohydrate, fat (including medium chain triglycerides (MCT) labeled with 13C3 tri-octanoate), and protein.
- control: on one occasion subjects will have received an isocaloric diet (55% carbohydrate, 30% fat, 15% protein) during 4 days. On the morning of the 5th day, they will be studied for 2 hours in basal, postabsorptive conditions and over 6 hours following ingestion of a meal providing ca 10 kcal /kg body weight and containing 55% carbohydrate, 35% fat (of which 15% medium chain triglycerides (MCT) labeled with 13C3 trioctanoate, and 10% protein.
- acute increase in protein intake: on the second occasion, they will have received an isocaloric diet (55% carbohydrate, 30% fat, 15% protein) during 4 days. On the morning of the 5th day, they will be studied for 2 hours in basal, post absorptive conditions and over 6 hours following ingestion of a meal providing ca 12.5 kcal /kg body weight and containing 45% carbohydrate, 30% fat (of which 13% medium chain triglycerides (MCT) labeled with 13C3 trioctanoate, and 25% protein.
- chronic high protein intake: on the third occasion, they will have received an hypercaloric diet ( 130% energy requirement, providing 42% carbohydrate, 23% fat, 35% protein; this corresponds
Sponsor: University of Lausanne
Current Primary Outcome: Whole body lipid oxidation Medium chain triglyceride oxidation Long chain triglyceride oxidation VLDL-triglyceride kinetics Hepatic de novo lipogenesis whole body glucose and glycerol turnover [ Time Frame: acute effects of dietary proteins and after 4 days on a high protein day ]
Original Primary Outcome: Same as current
Current Secondary Outcome: Energy expenditure Glucagon/insulin ratio Plasma growth hormone concentrations gene expression in subcutaneous adipose tissue Plasma ketone bodies concentrations [ Time Frame: acute effects of dietary proteins and after 4 days on a high protein day ]
Original Secondary Outcome: Energy expenditure Glucagon/insulin ratio Plasma growth hormone concentrations Plasma ketone bodies concentrations [ Time Frame: acute effects of dietary proteins and after 4 days on a high protein day ]
Information By: University of Lausanne
Dates:
Date Received: November 14, 2007
Date Started: January 2009
Date Completion:
Last Updated: February 9, 2012
Last Verified: November 2009
