The cravings that come with pregnancy may not be of the same dynamic as the cravings that come up with food addiction. Food addiction cravings can range from the most common triggers, sugar and starches, and then can become quite specific to the individual. In some cases, cravings can even be for large volumes of food, regardless of what that food is. I think it would be best to ask the obstetrician how to curb cravings, as these may be hormonal based.
If you think your cravings have more to do with the desire to eat for comfort or to moderate your mood, and are not related to the hormonal changes that the pregnancy has brought on (and this is something you should first discuss with your obstetrician) then the best solution is to abstain from the food that you most crave ie the chips and other ‘junk food’. There is no medication or nutritional supplement that can stop these if you are still eating the chips, though there are some supplements that may help i.e. magnesium for chocolate cravings, once you have stopped the trigger foods. It is best to consult a nutritionist for more information of supplements.
Cravings may take a week to two weeks to settle, but if you do not eat the food (and hence start of the craving cycle) then the cravings start to fade and eventually subside. They start up again the moment you pick up the chips or the cookies – this will reactivate the addiction circuitry to bring the cravings back as strong as ever.