We spend a staggering four and a half billion pounds on diet drinks a year. They now make up almost half of the fizzy drinks market, but do diet drinks deliver on their promise? Do they help us keep the weight off? In this episode, Prof Alice Roberts finds out about the latest research which suggests that drinking artificially sweetened drinks can encourage us to eat more than we might expect. Chef Tom Kerridge is on a mission to help with another kitchen fail. This time he's in Glasgow to sort out a viewer's yorkshire puddings and help them cook perfect yorkies every time. The supermarkets offer own-brand products across a range stretching from basic standard to premium. But is it worth paying for a premium product or is a money-saving basic as good for our health and our taste buds? To find out, our consumer journalist Sean Fletcher is dissecting a store cupboard favourite - baked beans.