[crazygringo]

Coke Zero is literally 99+% water.

Some people like flavored/bubbly water over plain flat water. Some people do Perrier, some do LaCroix, some do Coke Zero. All of these are essentially nutritionally identical.

Really just a question of whether you think the artificial sweetener has an adverse effect on your health, which in these quantities it doesn't seem to. And if you want caffeine -- the caffeine in a liter of Coke Zero is the same as a single cup of coffee, so this is the same as a fairly normal 2 cups of coffee per day.

[lagniappe]

that much dark stuff going through your kidneys to become clear can't be good.

[ed25519FUUU]

Don’t many people drink 2 or even 3 cups of coffee a day?

[crazygringo]

That's not how the body works. And it's just caramel color.

[copperx]

Not just caramel color. Phosporic acid, which is found in cola drinks and not sparkling water, creates kidney stones.

[crazygringo]

But the effect is mainly in sugary drinks, not diet. In fact, a study found that diet cola decreased kidney stones, although not meaningfully, so it's probably zero effect at all [1]:

> "There was a 23% higher risk of developing kidney stones in the highest category of consumption of sugar-sweetened cola compared with the lowest category"

> "Artificially sweetened sodas were marginally associated with kidney stones, with an inverse relation for colas and a direct relation for noncolas."

So no worries about your Coke Zero giving you kidney stones. The culprit seems to be the fructose, rather, which Coke Zero doesn't contain:

> "Higher consumption of sugar-sweetened soda was associated with a higher incidence of kidney stones, which may be because of the fructose content. Fructose has been shown to increase the urinary excretion of calcium, oxalate, and uric acid, thus increasing the risk of stones."

[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3731916/