How good is chewing sugarless gum while I'm having food cravings?

Not useful. Food cravings in a person with healthy taste buds should be respected and satiated with small servings. Your body is telling you what nourishment it requires. Trouble is, most americans have taste buds tricked by food artificial flavorings so they can't be trusted. The middle of the grocery store with its additives in each package must be avoided to recover the taste buds to normal behavior.