Seed has a wery interesting article now about meat and its effect on the global development. An interesting point there is that former largely vegeterian societies like China and India can now afford to become meat societies which is causing quite a strain on their grain production. They can't sustain their meat production and therefore have to import food for their livestock. This in conjunction with ethanol production for fuel puts huge strains on grain production over the whole world which is driving prices of food up which is especially bad for Africa (just saw the movie The Constand Gardener and am therefore a bit sad about Africa at the moment).
Another thing that is interesting, producing one kg of beef takes about 20 kg of grain, one kg of poultry takes about 4.5 kg, 1 kg of salmon takes about 1.4 kg of feed (what kind of feed do they need?). Why not buy fish instead of beef next time you go shop? At least eat more chicken then beef. I love beef, I love lasagne, beef with spaghetti and all kinds of beef dishes, but for the sake of our future we really do have to cut down our consumption of it. According to Seed then the average american consumes 100 kg of meat (I guess that is per year), that is 100/365 = 0.274 or 274 g of meat per day which is a good steak (I just ate a 300-400 g steak just two days ago).
Think about it.