Expression: sagged back

[Haihao]

Hi,

Could you please help me make out the meaning of the following sentences?

Yossarian gorged himself in the mess hall until he thought he would explode and then sagged back in a contented stupor, his mouth filmy with a succulent residue. None of the officers in the squadron had ever eaten so well as they ate regularly in Milo’s mess hall, and Yossarian wondered awhile if it wasn’t perhaps all worth it.

1. Does ‘sagged back’ imply the subject sat himself back in a chair or something?

2. Does the 2nd underlined part mean: The officers in the squadron only ate so well regularly in Milo’s mess hall?

3. Does the 3rd portion mean: Yossarian thought for a while that it was perhaps all worth it? If so, does ‘it’ refer to enjoying good food?

Thank you!

Haihao

[Mister_Micawber]

.
1-- Yes
2-- Sort of; the past perfect suggests that they never before did so.
3-- Yes. I suppose the first ‘it’ is ‘enjoying good food’, but that leaves us with the 2nd ‘it’.-- some trouble or hanky-panky assembling the meals? Or maybe Yossarian is talking about some greater truth, like serving in the military.
.

[Haihao]

Good morning, Mr Micawber. Your comment ‘Or maybe Yossarian is talking about some greater truth, like serving in the military’ made me completely wake up too!

Thank you again!

Haihao