It is natural to inquire what the connection between sweets and the somnolence may be. In my profession we make up stories to go with what seems to be happening before our eyes and so, knowing that I know nothing of this business, I offer a rationalization anyway.
In my reading about tumors I have learned that they need glucose to grow and those rich foods may supply glucose to Barbara's tumor in abundance. If the tumor swells, it will press on the surrounding blood vessels and so cut off the blood supply to (at least parts of) her brain.
This may not be sound medical theory but, taken with the advice of the physical therapist, it points to a suggestion that I hope that we may be guided by.
Happy new year to all,
ed