this guy would drink about eight 2-liters of pop a day

I'm surprised he's still alive. The average sugar content for most soft drinks is 120 grams/litre so he's at 1.920kg of sugar a day (just from the soft drink). The average person consumes about 1kg of sugar/week. One hundred years ago the average person would have consumed that in a year.

As for the caffeine content 1L of cola (cola's a good moderate ground) contains ~100mg of caffeine. So he's consuming 1.6 Grams a day. The deadly dose (as in you will die) for the average person is somewhere around 10 Grams. Consuming this on a regular basis will lead to all sorts of troubles from heart problems to severely decreased bone density (oops, I stood up, there go my legs).

Now 86.4% of stats are made up (including that one), and I'm not a doctor (or anything resembling one) and everything I've stated could be completely false, and I assume no responsibility for anything (especially that incident back in the 70's). I encourage anyone interested to research this further on their own.