What about potatoes, good or bad?
Potatoes have had a mixed reaction in diet books. The book Potatoes not Prozac, by Kathleen DesMaisons, shows how the natural serotonin in potatoes makes us feel good. Michel Montignac points to the high glycaemic index of potatoes and advises us not to go near them.
The advice in this book is that the whole potato is OK (i.e. a jacket potato in its skin), as it is not processed, but the processed versions of potatoes are not OK – oven chips, crisps etc.