[pjbster]

Just decide to do it. You'll work it out. You already know what you need to know - sugar is bad and if it comes in a package it's almost certainly unnatural.

Take a look at http://www.marksdailyapple.com/

If there's one thing you need to hang on to it's this: no matter how starving you feel, you're not going to die if you don't eat something! Your body can go for three weeks and more without you taking in anything more than a few glasses of water each day.

In other words, if you can't eat something natural, don't eat anything at all.

You. Do. Not. Need. That. Snack.

(Personal anecdote: I trained for an ultra endurance event a couple of years back and used to set off on 100-mile rides without eating breakfast first. Once your body adapts, you'll be amazed at how little you actually need to consume to really feel alive.)