The stiff statues of their past had been inspired by Egyptian statues of gods and kings, but after experiencing their own victory against the Persians, Greek art started to take on its own style that glorified the individual human body. Classical period artists generally created images of young people in peak physical health — athletic ideals. They went from stiff images of God-strength to voluptuous statues that showed their strength and nobility with anatomically correct musculature, something that could inspire sexual desire from the viewer. There was definitely a shift toward showing fit buns. A great example is the Kritios Boy, who surpassed the Egyptian-inspired Kouros figures in male beauty. In the carved panel of Nike, you can see her beautiful, healthy body through the drapes of tunic. She brings the gods to earth by adjusting her sandal in an almost awkward pose.
In the case of buildings, temples were stately and rectangular feats of architectural math, but parts were purposely curved in the Classical period so that they seemed more alive. Buildings and bodies were judged by mathematical perfection, but needed to seem lifelike. The temples were built with a mind toward how they would be seen from a great distance away — to counteract visual illusions that would dampen their grandeur.
I realize that I’m supposed to answer that contemporary humans have a similar preoccupation with ideal proportions, and with young people in peak physical health, but I think we are actually moving away from it. There has been a range of beauty expectations in every generation of Western society – of which the most reasonable focused on advertising health, but now our focus on inclusivity seems to be leading to a trend in Rubenesque models with a dismissal of ideal proportion based on health.