The reason why a soda and calcium loss relation was theorized (but never proven) has nothing to do with the structure of the soda itself, it’s because people who drink soda are not drinking milk, whereas in the past one would drink milk occasionally or regularly.
The primary reason why soda is not healthy is because it’s sugar water, and our bodies have a much harder time gauging and limiting liquid calories versus solid calories. Soda is essentially empty calories, sugar and salt and a bit of other minerals they throw in to make their nutrition label look better. It doesn’t do your body very good.
Compare this to a glass of water, which has pretty much nothing in it, no calories, a clean taste. Water is what our bodies want when they tell us we are thirsty. If you become thirsty and turn to a soda, you will consume a lot of sugar and salt, which will only make your body more thirsty in the grand scheme of things. So you drink another soda… you see where this goes.
Diet soda is not much better (I’m not 100% comfortable with high amounts of aspartame), and honestly, if you’re looking for a good diet drink you can’t beat water (in fact, go with ice water for a completely negligible boost in energy burning). Try some tea for taste if you find water too bland. I honestly can’t see why anyone would drink a diet drink in lieu of water or tea… filling yourself up with all those chemicals when your body really just wants wonderful hydrating water.
I agree that HFCS is no more worse than regular sugar, our bodies process both pretty much identically. The real culprit is the fact that HFCS is EVERYWHERE, in pretty much every single processed “food”.