Do you know how skinny your muffin is? How lean your mince is? Or what's in your low-fat yoghurt? As the public try to grapple with confusing messages about what's best to eat, Dispatches investigates how the food industry has reacted to our fear of fat. Through testing some of Britain's best-known food brands, reporter Antony Barnett reveals surprising evidence that suggests there are worrying inaccuracies in the labelling of fat content. With the help of the public, Dispatches also shows just how confused we are about the myriad of labels now used for low and reduced-fat foods. Analysing dozens of these products, Barnett reveals how some can contain huge amounts of sugar, calories and, in some cases, high amounts of fat. And one couple eat nothing but low-fat foods for seven days. What effect will this have on their intake of the ingredients we try so hard to avoid?