Apparently a cat's smell is good enough to do a molecular breakdown of chemicals up to 30 feet away and from this can decide if a food is toxic or not.

...of course substances that have chemicals that do not release an odor can confuse kitty (like Antifreeze which is masked by a "sweet" smell that attracts them)

...and of course the kitty itself may decide not to listen to its taste-buds

...and again, if kitty's human owners are enjoying something then it MUST be offerred to kitty, at which point they'll turn their noses up at it with that "what are you trying to offer me that muck for!?" expression

Bless them all.

PS. Yogurt is very good for cats.