If there were no more to your brain than primal instincts, you would not be capable of typing things at your computer.
Here's the difference: what you're saying is rather like declaring that you're going to love licorice, since it's a sugary candy, and humans have an instinct to gobble sugary foods--without ever having tried licorice.
You are not the first to think this. Life is remarkably complicated, and things tend to turn up or happen in real life with astonishing frequency that you never would have anticipated. No human, me or anyone else, is actually clever enough to figure everything out without the need to experiment and experience things.
I disagree with your first statement. As I said before, you can attribute almost any form of human behaviour to survival instincts.
As for the fact that you think I'm going to suffer as a result of my decisions, well, I can't see why you would be so concerned about me.
About your metaphore...well, following these instincs will guarantee me satisfaction- since in the survival/instinctual perspective, it would always benefit my genes (at least in the past...and the evolutionary hangover, well, I cannot help it). Consuming too much sugars (energy) is not always a good thing. Yes, Energy is positive to us which is why you are drawn to sugary food. But up to a certain point.
And besides, as I said before, I can't help it. In the same way that you cannot help dating a person who is completely unattractive to you. Not consuming certain foods because of their bad reputation...i think I can tolerate that.