You're right. When you're young you can get away with all kinds of crap, because you have tremendous inner strength and endurance. Most of us don't begin getting digestive problems, for example, until the 40's, 50's, or even later. But then it takes a much longer time to return to any kind of depleted health.
You're lucky you've become aware of these problems at an early age. You can be in really peak health.
"When the search for truth is confused with political advocacy, the pursuit of knowledge is reduced to the quest for power." - Alston Chase