As I mentioned elsewhere, this is also better for who this book is aimed at - poorer people. They generally have less disposable time on top of lack of money, s

As I mentioned elsewhere, this is also better for who this book is aimed at - poorer people. They generally have less disposable time on top of lack of money, so will prefer less time consuming, but more expensive meals (such as fast food, ready meals). If instead they could prepare a load of (say) stew that would last for a weeks worth of lunches and dinners, it would be much easier for them spend less money on food.