The cravings are just a symptom of low blood sugar, and your body telling you to eat. Eating as little as 10 grams of fast carbs (a single piece of candy) will "ruin your appetite" and hold you over until you can eat a balanced meal of slow carbs, fast carbs (important post workout), protein and poly and mono saturated fats.
If these cravings are bad, post workouts, it's indicative that you are under eating. Eat more food throughout the day, and particularly pre-workout, to keep your blood sugar a bit higher. Pre workout, we'll often bring our glucose level over 200, especially on leg day, where just three sets of squats can drop blood sugar to 130. Cravings are the natural way of your body telling you don't have adequate nutrition. Post workout, your glycogen uptake can be extreme and it's real important to get carbed back up and get some protein in that golden hour after resistance training, or any training, for that matter.
You can get a blood glucose meter anywhere.
If your blood sugar is below 80, you'll really start to notice a variety of effects. Hypo glcyemia always bothers me, and at about 82, or lower (some folks don't get bothered in the 80's, and can get down in the 60s before they have problems) I'll start having trouble.
Understand this is all sports science, and applied properly, you can have much greater success.
Repeating: when you have cravings, it's because your body is telling you that your nutrition is not right. Low blood sugar, or low overall calories, or both.
Understand this is EXACTLY why fat folks fail in diets that lack carbs, and when they eat in an upside down way, they go off and binge, because their brain is saying feed me (they are undernourished).
Take this to bed with you:
Breakfast like a king.
Dinner like a prince.
Supper like a pauper.
It will serve you well.