system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5:What prevents our bodies to get rid of excess food/calories that are not necessary, and instead turns it into fat?
gpt
Through most of human history and that of our evolutionary ancestry, storing energy was beneficial to survival since food was more difficult to come by. As a result, we evolved to store excess calories for future energy. But now we live in a society of abundance where it is not as useful.