I agree, especially about the need to eat properly beforehand.
Generally speaking (not referring to SF in particular) people often start fasts without any preparation or planning at all.
People fail to plan around social events, fail to plan their refeeding, fail to take time off work and relax, and haven't researched it properly beforehand.
I am sure that is why so many fasts go wrong, whereas Shelton's and others' went all right because they did things properly.