If someone needs to supplement with more than 50mg zinc, there is a serious digestive issue.
Sure maybe he needs more magnesium, but MOST people wouldn't need that much. MAybe the OP does. There is little problem with taking more (besides loose stools), so by all means try more and see if that helps. Taking too much zinc for extended periods WILL have side effects.
What kind of magnesium are you taking? MORE IMPORTANTLY what magnesium rich foods do you currently consume?
How much would you suggest? How could you possibly know the nutrient needs of the OP without lab results? What expert or athlete do u know that places 50 mg as a dose nearer the lower end of their spectrum? 50 mg is not a dangerous dose (but borders on the range that could potentially cause side effects) and I didn't say that he absolutely didn't need to SUPPLEMENT with that much. I simply said he "may" not need that much because the OP (or anyone) must factor in total nutrient intake from all sources. An athlete may perform best at around 50 mg from all sources, but how crappy would the diet have to be in order not to contribute to that total?And how could you make such a comment without any regard to the nutrients which will likely be thrown out of whack from a dose of zinc like that (i.e. copper and others)?
Yeah, stop drinking soda. Find your source of motivation that will lead you away from it and just do it.