If you are truly devoted to your health, logic dictates that you will be sitting at the dinner table with an empty plate - and certainly a frown on your face.

frown 是名词，意思是"皱眉"，指眉毛向下收紧、额头出现皱纹的面部表情，通常表示不满、困惑或思考。这个词也可以作动词用，表示"皱眉"的动作。