I feel like the obvious thing to point out in this whole discussion is that this practice isn’t inherently religious at all. You can reap 100% of the benefits of fasting without the religion.
I've been thinking about something like this recently. I was raised Catholic but have since become atheist. I've connected the health benefits of fasting and eating less red meat to some of the practices in Catholicism during lent. Personally, I find it hard to remember to try and do a fast or really build a long-term avoidance of red meat. So lately I've been thinking that while I may not believe in any gods, becoming "culturally Catholic" and re-adopting some of those practices could give me the structure I need to make some of those beneficial changes.
Many religious practices are borrowed from other religions or have some secular origin/reasoning. This is especially true for many of the food restrictions. Prior to germ theory, you ate something unclean and now God must be punishing you for it, etc.
"I think atheists actually empathize with the poor even more"
I think both this statement and the one you are responding to are getting to general/stereotypical. Fasting can be some meaningless ego/status religious thing. Just as some atheists might be more empathetic.
In my limited experience, the religious fasters seem mostly to be doing it because their community (church) does it and they want to belong, not for the exercise in self control or empathy. Although i msure both exist. It's also been my experience that atheists aren't any more empathetic towards the poor than the average person, religious or not.
I would disagree. As a Christian who practices fasting, one of the purposes (probably the major one, in my opinion) of fasting is to focus oneself more on a relationship with God. I can see how there can be secular benefits to fasting, but I fail to see how athiests would reap this particular benefit.