thin, emaciated, cadaverous, pinched, haggard, lean, wasted, bony, skeletal, raw-boned, more...

plump, chubby, corpulent, rotund, well-fed

skeletal, emaciated, haggard, gaunt-faced, gaunt-cheeked, more...

old, little, tall, aged, few, great, same, young, own, poor, red

very thin,   extremely thin,   thin and bony,   too thin,   sickly thin,   haunted look,   extremely skinny,   thin face,   thin and pale,   most thin