My pregnant sister is craving for really bad stuff (i.e. junk food). How did you combat your cravings?

I craved for the bad stuff too. Juicy fat burgers were always my request and there came a time that my partner and argued with it because I'm really hard-headed. I ended up having preeclampsia at the latter part of my pregnancy (34 weeks). After that, I was on a very strict diet but I would sometimes cry for not eating to my heart's content. My advice: keep insisting on self-control. If I could turn back time, I wish I didn't eat a lot. I got lots of stretchmarks after. I got confined prior to giving birth. There are times I said to myself, I wish I listened to my partner and my OB. Haha!