From releasing hormones to regulating our temperature, fat has myriad roles in the body. Here's why chasing extreme fat-loss goals is so unhealthy. Fat has been somewhat demonised for years. Diet culture tells us to burn it, some food companies market low-fat products at us, and weightlifting forums share tips on how to reach as little body fat as possible. You only need to spend a moment scrolling through social media and you'll soon find advice on how to "get shredded". This sinewy physique is defined by extremely well-defined muscles. (BBC News)