If you are in the UK and you didn't watch them I suggest you look for them on iPlayer, BBC4. For everyone else they are already available on YouTube which is earlier than usual I think
rigb.org/christmas-lectures....
They are all about food this season - and the third lecture is a real eye-opener about UPFs and how, actually, they can be made without ever seeing any real food. And the tricks they use to make us want more, and more ...
I'm a scientist and I love them - if you aren't versed in science, they make it accessible to everyone. Do have a look and I hope you enjoy them.