Welcome to the MedHelp forum!
You will be surprised to know that stomach ulcers and severe acidity can result in hunger pangs. Even GERD presents with similar symptoms. At times the hunger pangs due to acidity wakes up a person in the wee hours of night. If you are on contraceptive depot shot then this can cause acidity and make you feel as though you are hungry due to lot of acid. The other possibility is diabetes, hyperthyroid states and worms in the gut. All can keep you hungry 24x7.
It is difficult to comment beyond this at this stage. Do consult your doctor.
Hope this helps. Take care!
What's "the shot"? If you are talking steroids or synthetic female hormones, you can gain weight. And it would be natural for you to gain weight if you are eating 24 hours a day. What are your TSH and blood sugar levels?