A group of young atheists have taken up Lent without the religious context. They seem attracted to the idea of giving up a bad habit and replacing it with a good one. But they make it clear, they are observing the Christian practice, intended to spiritually prepare believers for Easter and a new beginning, because they want to, not because God told them to. Still, the story in the Christian social justice website Sojourners points out that the exercise has exposed "a divide in the nontheist community between older atheists who see religion as inherently evil and younger atheists who are more open to interactions with religious belief."
Read more about this group of atheists who are observing Lent in this article on Sojourners.com.