According to a recent study, obesity increases the risk of dying of Covid-19 by nearly 50%. Governments around the world are now hoping to encourage their citizens to lose weight. But with so much complex and often contradictory dietary advice, as well as endless fads, it can be hard to know what healthy eating actually looks like. How many pieces of fruit and vegetables should you eat a day? Will cutting out carbs help you lose weight? Is breakfast really the most important meal of the day? Speaking to Tim Spector, a professor of genetic epidemiology at King’s College London about his new book, Spoon-Fed, Madeleine Finlay asks why we’re still getting food science wrong, and explores the current scientific evidence on snacking, calorie labels and ultra-processed foods. Help support our independent journalism at theguardian.com/sciencepod