Are store-bought dehydrated meals odor proof as far as bears are concerned?

Yes.

Even a chipmunk can smell them – and will rip them open for you.

Definitely not all of them are odor proof…i have a plastic container where i store my REI bought dehydrated meal packets and the smell is strong enough that i have to keep it away from the other camping gear….cheers

That was a good question, and good to know they aren't odor proof. The one thing I've noticed about them is after re-hydrating them, the odor of their contents seems to permeate my clothing despite taking great care to get nothing on me. It's like the vapor just clings to the fibers of my clothes, and I feel like I smell like dinner to the bears after eating one of those.

It is amazing how odors can get through most odor proof bags.
Humans may not be able to smell the food, but bears, dogs, … can sure smell it.

One good thing is that it is a very faint smell and so usually isn't strong enough to attract animals from a long distance.

I have heard that a bear can smell when you open a can of tuna from miles away.

So don't pack tuna(or any fish) in bear country:-)

I have also heard that bears have a very good nose for fat of any kind, including vegetable oils that humans have a hard time smelling.

Absolutely not! Last winter we had mice infest our house. They had a heyday getting into the food in my gear room. Got into freeze dried food bags, energy bars, and energy drink mixes. All were in original packaging.

Put ALL food in that bear canister!

Jim