Originally Posted by Longfemur

In addition to this, most people who go vegan do so without adequate knowledge about appropriate amounts and combinations of proteins, and so they end up protein malnourished... which means the body consumes its own muscle tissue in order to get the protein it thinks it needs. Result: significant loss of muscle mass. Muscle mass is not fat. You don't want to lose muscle mass, even though it would make you weigh less.