You can get Very High Calorie Carnation instant breakfast I know through prescription and also online. Also, I think Walgreens carries it. It kept me from losing too much weight. My jaw was partially removed and I was not allowed to even swallow water for over a month. The chocolate is the best flavor I thought.
Try one and see.
Good luck to you,
Debbie

Partial mandibulectomy and neck dissection 2/3/07. T2NOMO.
Had 14 hour operation which included reconstruction of jaw.
Reconstruction failed. Some radiation, no chemo.