The ego's purpose for the body is only to serve itself. Some egos demand incomprehensible dedication to transform the body into a maximally attractive temple to itself.
The purpose behind the endless hours of painful workouts and dieting is not so much to attract lovers or enjoy sex--for that would demand opennes and intimacy, which the ego cannot do. The purpose; rather, is only to prove superiority by being the most physically attractive.
The ego loves attention and lustful stares, only because each is seen as a testiment to its grandiosity and a boost to its ugly need for pride.
Sometimes, particularly for men, the lustful or jeoulous stares don't come even if you are physically attractive. Now, to get that boost of pride, seduction is required. Here come the one night stands. Bodies must be conquered, false promises made, cruel games played, the more the better; not exactly for the joy of sex (though sex always feels good), rather, to win and prove superiority.
Most egos don't win at this game. There can only be one fittest body in any room. It then tries to adorn the body with more attractive clothes, it may buy expensive cars, possessions, and use countless other strategies to appear more attractive. But, at some point, we all lose at this game.
Some people give up early in life, some in marriage when the game is no longer allowed, others later on in old age. Now the defeated, victim ego uses the body to numb its pain. Now comes the food binges, the addictions, the total destruction and neglect of a body that has failed to serve its delusional purposes.
The ego is no friend to the body; rather, an exploiter that looks upon it and uses it lovelessly and in disgust. This is the root of sickness and disease.
An awakened person, one who has made the decision to escape the ego, truly loves the body, accepts it as it is, nurtures it, enjoys it, and offers the same loving attention and care to the bodies of loved ones. This person sees no competition, only beauty where it lies. This person is never ill, and looks very good even into old age. This is self-love.