I've only recently got back into weight loss after a 1 year period of maintaining a 60lb loss. This has been mainly through higher activity, a higher muscle mass and living away from home so less binging, though I still ate an unreasonable amount. Unfortunately though i noticed the numbers were slowly moving up and i realized i should get back on track with my weightloss.
So, I started out like i have in the past, keeping a food diary, eating the lowest calorie options available, not snacking etc. Now what's bothering me now (which never did in the past) was how little i've ended up eating. i'm barely eating 1000 kcals a day and some days not even. This would not have bothered me before 'cos i never cared about losing muscle mass, I never had any before, but after reading about "starvation mode" it's got me worried.
I've always aimed for losing weight as fast as possible and Very Low calorie diets have been my norm and i find them very easy, it's keeping it in-between and at a slow loss rate that drives me crazy - But i don't want to lose my hard earned muscle.

Has anyone else been in this boat? any tips on keeping my muscle mass but still maintaining a good loss per week? (2lbs or more)

My work schedule is 8 days on (out in the field, hard labour, camping and group cooking) and 6 days off. Now on my work days i do eat up to 2000kcals, i need it. But is it enough to counteract the low low counts on my 6 days off. Is 6 days too long to go at such a low count.

any thoughts appreciated