Food and Environmental Security

I researched why food and environmental security weren't mentioned in the declaration but I couldn't really find that much about it. I think that maybe it's not in there because both issues are extremely important and kind of really complicated? Food security isn't something that can be completely protected by a few statements and neither is environmental. Also when it was written (I'm really just guessing here) maybe world hunger and environmental problems weren't such a big deal as they are now. I mean obviously they were around but maybe not all countries were aware of food and environmental problems so they didn't feel the need to have to protect it in the declaration.