The Metabolic Effects of Consuming Carbohydrate With Different Protein Types

Overview

This study aims to find out how consuming different proteins with rice affect metabolism. Most meals the investigators eat predominantly consist of a carbohydrate and protein (i.e. rice, noodles, bread etc with meats or seafood). However, it is still unknown how consuming different proteins with commonly eaten carbohydrates affect metabolism. Previous studies have shown that proteins stimulate hormones such as insulin, glucagon and gut hormones. However, the extent of the response depends on protein type. The metabolic responses to carbohydrates have also been shown to be greatly affected when they are eaten with proteins. However, most of the previous studies have used glucose as the carbohydrate and it is still unknown how eating proteins with carbohydrate foods such as rice affect metabolism. Therefore, this study has been initiated to determine the metabolic effects of eating different protein types with rice. Using the most common carbohydrate eaten in Asia (rice) and four commonly eaten protein foods (egg, chicken, fish and beancurd), this study aims to observe the metabolic effects of co-ingesting proteins and carbohydrate. The resulting data will provide valuable insights into the metabolic effects of protein-carbohydrate meals and will be useful in the development of practical advice and dietary guidelines for those with chronic diseases (such as diabetes and obesity).

The study will recruit 20 healthy Chinese male subjects from the general public over a period of one year. The test foods will be rice, rice with egg, rice with fish, rice with chicken and rice with beancurd.Potential participants will have to come on one morning in an overnight fasted state for consenting and screening procedures. Only those fulfilling the inclusion and exclusion criteria will be admitted into the study. Each participant will be required to come on 5 non-consecutive days, with each session lasting approximately 4 hours. On each day, participants will arrive at the laboratory between 8-9 am following an overnight fast. An indwelling catheter will be inserted into a vein in their forearm or antecubital fossa and kept patent. Baseline blood samples will be obtained after which they will be given the test food to consume. Further blood samples will be taken at periodic intervals for the subsequent 3.5 hours. Blood samples will be taken every 15 minutes in the first 60 minutes and every 30 minutes for the remaining 150 minutes. At every time point blood samples will be extracted from a finger prick (for measuring glucose) and from the cannula (for measuring all other metabolites). At the same time points subjects will have to fill in visual analogue scales on feelings of hunger and satiety.