I don't think I could or would ever completely give up drinking Coca-Cola, but I could probably cut down on how much of it I drink. (This would also apply to Vault Soda, which I used to drink more of than Coke, until Coke rudely and with no respect for my feelings took it off the market.)
One of the trainers at the gym I go to, in order to help motivate me to do so, gave me a flier that talks about what happens to my body when I drink Coke.
I haven't fact-checked this, so take it with a grain of salt. But for what it's worth, here's what it says happens:
In the first 10 minutes, 10 teaspoons of sugar (100% of my recommended daily intake) hits my system.
Within 20 minutes, blood sugar spikes and causes an insulin burst. My liver responds by turning any sugar I can get my hands on into fat.
Within 40 minutes, caffeine absorption is complete and adrenosine receptors in my brain prevent drowsiness. My pupils dilate, my blood pressure rises, as a response my liver dumps more sugar into my bloodstream.
Within 45 minutes, dopamine production is increased, stimulating pleasure centers in my brain. This sounds cool. It's also how heroin works.
Within an hour, phoshpric acid binds calcium, magnesium and zinc in my lower intestine, which provides a further boost in metabolism, compounded by high doses of sugar and artificial sweeteners, which make me pee and evacuate the calcium, magnesium and zinc instead of using them.
Then the sugar crash begins, making me irritable and sluggish, pissing away all the water in the Coke as well as the nutrients.
OK, OK, when you put it that way...I'll try to cut down.