There are ways to battle poverty and its stigma. Here is one reported by Salon.com.
Right now, the Community Eligibility Provision is limited in its scope. Schools with a lot of poor kids will be able to implement universal free lunch, but not any others. Yet, it is those other schools with far fewer poor kids where the stigma is probably most severe. The only way to tackle this anti-poor stigma everywhere is to implement a full-blown universal free lunch program, like countries such as Finland and Sweden have done.
Every kid needs to go to school and every kid needs to eat while at the school. We publicly fund the school and we should publicly fund the school meals. In addition to the stigma-reducing benefits mentioned above, such a move would just generally provide relief to parents of all sorts and signal a communal commitment toward ensuring no child goes hungry.