i stopped eating meat for three months (it was supposed to be a permanent change) one summer and early fall. i was running 100+ mile weeks prior to that, but i was trying to keep up my training schedule while i was getting more and more fatigued every day. i eventually found out that i had an iron deficiency, but by then i had cut my mileage in half and experienced the most miserable three months of my life.

this could have easily been avoided if i had looked into what else i was giving up when i gave up meat (iron, protein) and shelled out some money for supplements. buying stuff like that seems sort of expensive at the time, but its nothing compared to the price of a burger times x number of meals. i'd imagine that being a vegatarian is a lot cheaper in the end. point is: you can get sick from what you don't eat (scurvy is another good case in point... you'd think that nobody gets that anymore, but i just met some kid who had it last year) but only if you aren't careful. if you're eating meat and leading a somewhat active lifestyle, you should probably look into what else you're giving up if you give up meat.