“If you take that [extra weight] and now lie flat… in bed the way all the doctors have been saying is best for this, which is to lie on your belly — we call it proning — most of the lung tissue is then pointing upward away from the ground, which makes it actually easier to move air in and get the fluid in the more dependent, smaller parts of the lung that are now face down,” Dr. Kass explains. "But if you’re pushing against your 80-, 100-pound abdomen with all that adipose tissue, that’s going to push up against your diaphragm, and it’s also going to make it hard to breathe. So, that’s the physics [aspect of this].”