Two decades ago in response to colleagues' worry that I was drinking too much caffeine I quit for a year. All sources of caffeine; espressos, energy drinks, diet cokes.

I didn't suffer any withdrawals.

However I greatly missed my coffee, so after the year I resumed (sans the energy drinks) and will be having my coffee until the day I die.

Quit alcohol nearly two years ago; that's a habit that can stay gone. Definitely feeling the benefits of ditching even what was a relatively modest consumption.

In a way, diet cokes (Coca Cola No Sugar) are my naughty drinks now - so I can see from this study I should probably limit it somewhat day in-out, and as long as I do it should be ok.

I primarily drink filtered water and filtered Sodastream water for my fluids.