The antonyms for the phrase "more skin and bones" can be a variety of words that indicate a healthy, robust bodily appearance. These could include phrases such as "well-fed," "muscular," "sturdy," "ample," and "plush." Each of these antonyms implies a physical appearance that is the opposite of "more skin and bones," indicating that the person or animal in question is well-nourished and healthy. Whether described as "well-rounded" or "thickset," these antonyms celebrate a physical form that is indicative of strength, vitality, and good health.