Metabolic Availability of Methionine and Lysine From Rice, Wheat, Chickpea and Lentil in Adult Men

Overview

The research study is being done so we can determine the quality of the protein present in Rice, Wheat, Chickpeas and Lentils. Amino acids are the building blocks of protein and protein quality is determined by the amount of amino acids present and by their bioavailability (their absorption and use by the body). Some amino acids are essential which means they must be obtained from the diet. If any one of the essential amino acids is missing in the diet, the body cannot make proteins that are used to repair tissue build bone, teeth, etc… Rice, Wheat, Chickpeas and Lentils as a food source contain low amounts of the essential amino acid methionine (Chickpeas and Lentils) and lysine (Rice and Wheat) which makes its protein incomplete. The amino acids in Rice, Wheat, Chickpeas and Lentils are also affected by cooking. Our objective is to determine the amount of methionine in Rice and Wheat and the amount of lysine in Chickpeas and Lentils that the body can use. This research is being done in order to bridge the gap between knowledge of protein requirement and the amount of food needed to meet that requirement. Results from this study will be important for recommendations guiding food choices of Rice, Wheat, Chickpeas and Lentils as a major protein source in the diet. Previously the quality of dietary protein for human consumption was studied in animals. This study is being done in humans because studies in animals are not always directly applicable to humans. Plant protein sources like rice, wheat, chickpeas and lentils are important protein sources shown to "enhance ecosystem resilience, and improve human health.

If you agree to take part in this study, you will participate in 7 different experiments for each food. For each food you will receive 3 different amounts of Rice, Wheat, Chickpeas or Lentils which will contain different amounts of the essential amino acid methionine (Rice or Wheat) or lysine (Chickpeas or Lentils). The quality of the protein in the Rice, Wheat, Chickpeas or Lentils will be compared to the quality of a reference protein (egg protein) by giving you 4 reference diets containing amino acids made up like the amino acids in egg protein. The amount of Rice, Wheat, Chickpeas or Lentils you receive will be provided in a random order. Each experiments will be conduced over 3 days- 2 adaptation days where you will receive the diets at home, provided by the investigators and 1 study day. On the 3rd day (study day) you will visit the Clinical Research Center (CRC) at the Hospital for Sick Children where you will receive 9 hourly meals. Breath samples will be collected after the 4th meal in 15 min intervals for 1 hour. Breath collection will resume again two and a half hours after the 5th meal every 15 minutes until 30 minutes after the last meal. A total of 52 breath samples will be collected during each of the 3rd study day. Before the study begins, you will visit the CRC at the Hospital for Sick Children for a baseline study assessment. At that time your body composition (fat and fat-free mass) will be measured and your resting energy expenditure will be measured. This will tell us the amount of calories your body need so we can prepare the diets for you for each experiment. This baseline assessment takes about 2 hours.