What is a good way to gain weight and to not be called anorexic?

What's happening?: In this world, people will call you many things, true or not. The fact that you want to gain tells me you do not have anorexia nervosa. If you appear ill and are very thin despite eating what seems to be a healthy diet, you may have malabsorption (celiac disease, whipple's) or maldigestion (pancreatitis, adult cf); get a workup. If you're merely well-defined, athletic and slim, it's sour grapes.