I'm not sure what exactly you mean when you say you can't eat according to your hunger. Do you mean that you get hungry but find yourself becoming nauseous when you actually start to eat? Do you experience some kind of pain or discomfort when you eat, which prevents you from eating as much as you would like? When you eat, do you experience a feeling of being physically full much before your hunger has been satisfied? Or do you simply mean that your schedule prevents you from eating when you're hungry, and as a result your health is suffering? Without knowing exactly what the nature of the problem is, it is difficult for us to provide you with a specific solution. As you can see, each of these problems mentioned is quite unique and will have rather different causes from the others.
If you experience pain or discomfort when eating, then the source of the problem should be quite easy to identify. However, you will need to visit a doctor for a proper diagnosis and for treatment. Depending upon where exactly the pain or discomfort is, there could be a problem with swallowing or with your digestion, in other words, the problem could be in or around your esophagus, or it could be in your digestive system. Your doctor will prescribe appropriate medicines, and advise you on any other measures that you need to take to solve the problem.
Nausea is a symptom that is a little more difficult to diagnose - often nausea has nothing to do with the digestive system. Excessive use of alcohol and even medically supervised use of certain prescription drugs can cause nausea. Stress, depression, and lack of sleep are other problems that can lead to nausea. Diseases like diabetes and serious problems like brain tumors are also capable of causing nausea on a regular basis. As you probably already know, pregnancy also often causes nausea that is commonly known as morning sickness, although it can occur at any time of the day. You have not provided any background information, so it is difficult to say what the cause could be. If nausea is what is stopping you from eating, you need to consult your doctor.
Finally, if the problem is simply that you have a hectic schedule, and then you will simply need to find a way around it. There is no substitute for eating your meals on time, and regularly ignoring your body's hunger can cause serious problems after a while.
answered by G M