Why do I feel hungry?

Are you hungry? How often do you stop to think about why that is and what sort of foods you are hungry for? In this programme Ruth Alexander explores the science of appetite – what causes us to feel hungry and full and why our appetites differ from one person to the next. Geneticist Professor Giles Yeo at the University of Cambridge in the UK explains how much of our appetite is informed by our genes and how much by our environment. Registered public health nutritionist Federica Amati, author of 'The Appetite Reset', explains what happens in our gut to help us feel full, not just immediately but for hours after eating. Amber Alhadeff, neuroscientist at the Monell Chemical Senses Center in Philadelphia, US says that GLP-1 weight-loss medications are changing what we know about appetite. And Ruth meets Darren Ratcliffe at his home in Manchester, UK. Darren shares how GLP-1 medications affected his appetite, and what happened when he stopped taking them. If you'd like to contact the programme you can email thefoodchain@bbc.co.uk. Produced by Beatrice Pickup and Lexy O'Connor. Sound engineer: Andrew Mills (Image: Darren Ratcliffe is standing in his kitchen. He is wearing a green t-shirt and holding a plate of food that contains a baked potato with tuna and sweetcorn and a salad. Credit: BBC).