We are pre programmed to be able to detect calorific foods by flavors. This is because we are designed to seek out calorie dense foods to preserve for periods of starvation. It's easy to get hooked on those foods when we are programmed this way. We don't need that survival technique though because clearly we live in the age of excess. When you don't eat those foods you don't have the taste for them and will instead crave healthier foods. You have to change your own programming.  MSG is a flavor enhancer and is addictive for the above reasons. Another issue is that it prevents the hormone responsible for telling you that you're full from passing through the blood-brain barrier, so you keep eating. That's why people can sit there and eat a whole box of cheezits without thinking about it.