There's no doubt that you should eat if you're hungry. We all know the term "hangry" which is a very real affliction that has very real consequence (like you being a complete jerk). Pull out an apple or a protein bar and munch away. You'll feel better and the people around you will feel better. I think that's pretty good advice, but what I don't mean by that advice is to pull out your produce and start chopping it right there in the subway.
This woman is suffering from the condition of doing the wrong thing at the wrong time. She's got one of the smelliest foods in the world right there, which makes it even worse. Not only are onions smelly, but they can inflict actual physical pain. When I cut onions I cry harder than when I watch Marley and Me.