Ask your "friends" if they know that they kill male baby chicks right after they are hatched since they feel that they have no financial value. Ask them if they know that older chickens are killed when they no longer product the number of eggs per day that they expect. Their attitude about eating only "free range" eggs and "humanely" raised animals is like saying that I only kill bad humans and it is even more OK because I do it humanely. Remember killing humans helps sustain life on planet Earth.
Your friend that wants to be a nutritionist said one of the dumbist thing I have heard for a very only time. It takes over seven times as much grains and veggies to feed a flesh eater than it takes to feed a vegan. An animal has to eat the grains and use part of it in order to live. More parts of the grains go into bowel and urine. Finally the last part goes into flesh of the animal. So it takes far less grains, veggies, and fruits to feed a vegan than a flesh eater.
As far as links please go to Vegan2050.org. VEGAN Resource Library has many good cyber pamphlets.
Yes, veganism is weird. Thanks goodness! The average person in this world has very little compassion. Vegans generally have a lot of compassion. This makes us weird.