Limited fruit juice, especially if it's still lumpy, isn't a bad thing, there's at least some added nutritional benefit. You can't say that for cola which is effectively coloured sugar solution with a bit of flavouring. And if you're drinking it with other food, like a bowl of porridge, you're effectively taking the sting out of that glycaemic punch. The other problem with sugary soft drinks is that they tend to drunk solo, sloshed into an empty stomach. It may be extreme for the UK, but it's not out-of-the-ordinary in the US to see people chugging away on big gulp size sodas. That's 30-odd spoons of sugar going direct into their bloodstream. Unless you're doing some pretty extreme exercise and have depleted glycogen reserves that's going to fat.
Of course, it all rolls up into the general excess of sugar that has found its way into our diet. Even fruit and veg has got sweeter. The big con is processed diet foods. Sugar was always known to be bad, the but sugar industry in US lobbied hard (that's why you never see percentage of daily amount for sugars on a nutritional label) for the focus to be retained on fat (which was only part of the recommended nutritional advice). This conveniently levered open an entire new diet food market for the big food processors. Of course, taking the fat out of food makes it taste like crud, so they bulked up with sugar and salt. The salt fell out of favour. So we have sugar. I cook tomato sauce by throwing a few tomatoes in a pan of garlicky oil, some herbs, and a splash of balsamic vinegar for sweetness, depending on how tart the toms are. A while back, I grabbed some supermarket tomato pasta sauce. It was so sweet I couldn't eat it. Custard isn't that sweet. I think sugar was the third ingredient.
