Tubuh manusia tidak butuh protein dari hewani karena dalam mata rantai asam aminonya mengandung sulfur yang metabolisme dalam tubuh menghasilkan asam sulfurik, prekusor asam. Penyebab osteoporosis dan batu ginjal. lebih lanjut baca:Sulfur-containing …amino acids in protein-containing foods are metabolized to sulfuric acid. Animal foods provide predominantly acid precursors; dietary animal protein intake is highly correlated with renal net acid excretion (r = 0.84, P < 0.0005) (9). In contrast, vegetables and fruit contain not only amino acids but also substantial amounts of base precursors

http://www.ajcn.org/cgi/content/full/ajcn;73/1/118

Credit : IVS