Also, don't reward her whining. It would be the same thing with a child. If you gave them what they want every time they whined, they'd never stop.
I agree with the above posters that the dog would benefit with more activity. Teach the dog, however, how to behave when she wants something. If you want her to sit at the door when she wants to go outside, teach her and reward that behavior.
Make her sit, give her a treat or a favorite toy, and let her out with plenty of praise. If she wants to go for a walk, teach her to lay by her leash and do the same thing. As for food, put her on a strict schedule and don't react when she whines. Teach her to sit patiently when you do feed her. (Also, always have water available, she should never have to ask for that).
Remember, it's not about stopping the behavior, it's about redirecting their behavior toward what you want them to do.