Talk to Dietitian/Nutritionist on Food Cravings

weight 47 mother of three I eat proper meals according to my hunger but after two hours I feel to begin hungry I have food cravings but when I try to overcome these cravings sonetimes I'm unable to digest food I feel heavy head and like my food is not digested I want to know the reason behind untimely cravings what sort of food I need to take do I have any deficiency which causes these cravings hopefully u get my problem.