In my opinion, a craving is your body telling you that it requires something its missing.
When low on energy, you'll most likely crave something with sugar. If you've been doing lots of sweating etc. you may or may not crave salty potatoe chips. A pregnant woman, ice cream to help with low calcium etc.
With me, getting sober, my body required alcohol because it had gotten so used to it, so I craved it, but just because my body says it needs it doesn't make it a good thing.
Being able to decide whether to give in, as in pregnancy, or deny, as in alcoholism is what counts.