Tim Spector and Kandi Ejio reveal the science behind why biscuits are so moreish and find out how many chemicals are lurking in a simple slice of ultra-processed ham. They also help Nick and Sarah from Cambridgeshire to ditch their sausage rolls and boxed wine in favour of fermented foods, and they demonstrate how to use natural ingredients to make cookies.

Professor Tim Spector and GP Dr Kandi Ejiofor help viewers to navigate the world of ultra-processed foods (UPFs), that are thought to contribute to the UK's rising obesity rates. They begin by revealing how some of the nation's favourite ultra-processed foods are made, starting with strawberry milkshake, and investigating exactly what ultra-processed foods do to the body. Tim and Kandi also help Vicki and Rob from Scarborough tackle their instant-noodle addiction and show how making simple swaps and cooking easy recipes can benefit a person's health.