I think Bryan and Elayne are saying the same thing, but I don't want to put words in their mouths and would like to read their comments. I do have a comment on the practical detail of Bryan's post however.
Full physical contentment is naturally and frequently achieved when we have the natural and necessary accommodations of food and shelter.
Yet full mental contentment can be achieved just as naturally and frequently as full bodily contentment -- by the very realization of the simple ease of obtaining bodily contentment and then fostering gratitude and a full appreciation for your success in doing so.
To me, these quotes are overly simplified (maybe intentionally?). I presume (correct me if I'm wrong) that most of us reading this have adequate food and shelter yet many of us have physical/medical issues that prevent full physical pleasure. And mental pleasures and pains have a major influence on physical well-being which may be either positive or negative. As a material body and soul, each individual has intricately intertwined mental and physical needs, desires, fears and pleasures which contribute to full contentment. The classic example is, of course, Epicurus feeling the fullness of pleasure while dying from strangury. But I think it's far more common for a person's mental distress to cause pain in the body despite adequate food and shelter.
Gratitude is a powerful tool, but a person must also apply the Canon and reason to their mental distress(es). Epicurus's extant writings show how this is done for the fears of the gods and death. I suspect that many other issues were dealt with through the use of frank speech in ancient Epicurean communities, although I'm not aware of any extant documentation.