Consider depictions of the human body during the Middle Ages (476 AD -1350 AD). Discuss a reason how and why they are so different from the Greco-Roman period.

During the Middle Ages (476 AD-1350 AD), the focus on Christianity changed the way in which the human body was depicted. In contrast with the Greco-Roman period, which had many nudes, this period of art produced very few nudes. Religious figures (except for Adam and Eve) during the Middle Ages were rarely shown nude, and other exhibitions of nudity that were common during the period of paganism (such as nude bathing or nude athletics), were not in favor.
A piece of art that shows this transition is the Sarcophagus of Junius Bassius, completed in Late Antiquity in 359 AD. This sarcophagus shows nudity as something about which to be embarrassed, as Adam and Eve are depicted as trying to shield or cover up their naked bodies. Art in the Middle Ages often featured religious figures; an example is the stained glass windows of Chartres Cathedral constructed around 1200, which feature religious figures in stories from the Bible. The human body in this era is simplified and even a little grotesque, as the artists showed little interest in the human form and instead concentrated on the spiritual. 
https://www.metmuseum.org/toah/hd/numr/hd_numr.htm