 My name is Professor David Cameron Smith. I'm a Chair of Nutrition at the University of Auckland. Very interested in how nutrition impacts on lifelong health. Our population is getting older so we need to do more to improve the health of those people. Once you're over 65 you tend to see the extremes in terms of ill health. On the one hand you've got rising rates of obesity and obesity drives heart disease and diabetes. But at the same time we get people with symptoms of malnutrition and symptoms of undernutrition. Undernutrition includes osteoporosis as well as sarcopenia which is the loss of muscle. So it's a very complex age. As you age you get lots of changes in your taste, your desire to eat and your ability to eat. So our research is looking at new ways in which we can increase the amount of food that people eat, the quality of that food but also the way in which we can incorporate the best ingredients to deliver the best biological function. So we're looking at protein supplements that can be used in hospitals, that can be prescribed by doctors and also used in nursing home environments. In our study we're looking at middle-aged men and we're imposing upon them an accelerated aging program. We're immobilizing one of their legs. When you immobilize someone's legs they lose up to five six percent of their muscle mass in a very short space of time. Now that's what happens to old people. When they're sick, when they fall, when they're injured, when they're hospitalized they lose a lot of muscle because they're in a bed. So what we're doing is we're looking at what happens to these individuals but more importantly we're trialing different types of therapeutic proteins to understand how we can maintain muscle mass and how we can accelerate that repair after an injury or illness. This study is carefully controlled so one group gets a placebo and another group gets an active protein powder. We control their diet so we can precisely measure the benefit of the treatment versus the placebo group. Our specialization is molecular nutrition so we need to get right inside the tissue to understand how amino acids are working at a cellular level. The way we do our research is by taking a muscle biopsy. That's a small little piece of muscle that we take from the individual so we can understand exactly how the amino acids are working inside that tissue. Whole body protein metabolism involves scanning the body and that's what a dexa machine is. It can help us get to three things, bones, muscles and fat and we do all three at the same time. We also use other technologies that allow us to take a high-resolution image that helps us look deeply into the tissue and to try to understand how it changes both in response to immobilization but more importantly what happens when you change types of proteins in your diet. Muscles are all about function so in addition to looking at the way in which the muscle changes we also have to look at people's function. So we run a range of tests to accurately measure the functional changes. It's everything from balance to power to maximal aerobic performance. We use a test known as a cycle ergometer to maximally exercise just one leg. Using this technique we can measure how much oxygen they consume but importantly how much power they can generate. Nutrition is vital for both the quality and quantity of life. Our aim is to understand how nutrition works so we can provide the optimal nutrition advice that's going to have the best impact on the health and well-being of this population.