#1 Chocolate
Even if your furry friend is curious about what you are eating, chocolate (and other types of sweets, for that matter) should never even cross their path! Sure, you can let them sniff it, since we know just how curious cats are, but you should make sure they never ever ingest chocolate.
This is because chocolate contains methylxanthines. They are specific substances that occur naturally in chocolate that can cause your kitty to end up having severe adverse reactions including diarrhea, seizures, tremors, vomiting, and, if a high quantity has been eaten, even cause death!
Since all chocolates contain methylxanthines in different concentrations depending on the type, you cannot stay calm no matter what the cat has eaten. But if we were to rank them, white chocolate has the least problems, while cocoa powder is the most dangerous!