People often misunderstand Asimov's laws, the entire point of the laws and the stories they're set in was that you can't just throw a simple "Don't hurt people" clause at a black box like AI and expect good results. You first have to define "Don't", then you have to define "hurt" and perhaps the hardest of all is you have to define "people". And I mean really define it, to the smallest most minute detail of what exactly all those words mean. Otherwise you very quickly run into funny, tragic and even contradictory situations, and those situations are endlessly unique.
Is feeding grossly unhealthy food to a starving person harm? Perhaps not, you can argue it's better to eat something unhealthy than to starve. What about feeding someone on the brink of a cardiac arrest that same meal? Now what about all the other gray areas involved here, you have to define every single possible situation in which an unhealthy meal might affect someone.
It's kinda funny, because it really is almost prophetic considering it's a story written quite a long time before we were even close to it being a reality...