smelly food, poop etc. what's a good brand?

I am new to this. I did some googling and I know that grains are bad? and so are by products. Right? Is there a list or something of good brands that don't cost an arm and a leg? I don't mind paying a little extra for something healthy that is going to be worth it in terms of health/smell.

I am feeding him Purina Naturals right now. He likes it fine. But it smells up the room and then his poop smells bad too. So if I get a better brand will the smell be less? The litter box is CLEAN. I've cleaned it 3 x today already. No smell there. But the room just emanates of "cat smell" and its' not him or his poop. Pretty sure it's the food.

I don't know what food to get. It's a bit overwhelming to be honest.

Yes it is confusing honestly dont know if bad poop smell is a bad thing. But it isnt always the food. But the food not agreeing with the cat. Cats dont need grains, or at least the majority of their diet should be meat. Look for foods with meat as the first ingredient not grains.

Some brands put an ingredient in the food to keep odors down. But not everyone likes that they do.
There are so many brands. But you need to see what your pet will eat. I have cats who will eat most anything, andvsome that only like a few brands.

Do you have pet stores near you?

There is a Petsmart near us. Also Tractor Supply and Rural king as well as big box stores. My mom feeds Iams, I think. She always said it was good. But then I read that it's not really the best anymore.

In general the better quality foods will cause less smell, but as @momof3b1g has indicated, it is not always the food.

Iams USED to be good, but we are talking a loooong time ago.

In general, you want a high protein/low carb wet food,  grain free. This article talks about choosing a good cat food for you:

http://www.thecatsite.com/a/choosing-the-right-food-for-your-cat

Be forewarned that all commercial cat food will have its strong and weak points. You just have to find one with the weak points you can live with.