I'm leaning towards @Deemar007's response.
It will be more beneficial for you now and in the long run to take on the weight loss journey yourself, vs. relying on others to adjust their habits to accommodate your chosen lifestyle. If you can succeed without the need for others to change, your successes will be in YOUR control, and theoretically be longer lasting.
I know this is easier said than done. Especially since you are only 3 days post op. The first week or so is the hardest. If you can, take the time and make the effort to sustain lasting change, you WILL NOT regret it.
P.S. Though I do also agree with the other poster that it wouldn't hurt to ask him not to bring sandwiches to bed. He can chose to decline your request, but I would think it's a fair request...I mean, even just from a hygiene and bug potentiality perspective...
Good Luck!