As far as I can tell, they're actually fine, but people who drink them tend to make unhealthy lifestyle choices. The majority of the really scary claims (like

As far as I can tell, they're actually fine, but people who drink them tend to make unhealthy lifestyle choices. The majority of the really scary claims (like this video) are total bullshit about pH levels and aspartame conspiracy, but it seems like the literature is conflicted on if people who drink them do end up fatter for some reason.