BBC documentary series The Men Who Made Us Fat is a fascinating mix of health, marketing history and the law of unintended consequences that has affected the modern diet. One phrase struck me as being a quite interesting. Expandables was a term to use a category of food products that would be part of multi-pack or buy-one, get-one-free deals. The products couldn’t be economic substitutes for instance discounting one type of meat would have it substituted over another meat-type.
In the case of food products it is usually items that people graze on.
Zoe Harcombe’s blog has a complete summary of the TV episode to put expandables in context.