Ack. TOM can be a killer.
Nothing you can really do about water retention except drink lots of water and watch your salt intake.
For the cravings, I think it depends on what you're craving. I will often have some good quality dark chocolate if I'm craving ... or will indulge in a *small* bag of Sunchips for the saltiness, and then count them into my calories.
If you're just feeling the urge to eat - go for something like celery or an apple. Something crunchy that will fill you up for very few calories.
And keep EXERCISING. Exercise will help with cramps and help curb hunger and cravings.
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