Zero-alcohol drinks are booming — but are they really harmless?

It wasn't long ago that zero-alcohol drinks were a niche product. Now they're everywhere, including on supermarket shelves, looking almost identical to the real thing.  New research warns these drinks — along with "low sugar", "low carb" and "low calorie" alcohol products — are blurring the line between drinking and healthy living.Is it time for tougher regulations?