No. However, employees who do have food allergies or restrictions would likely appreciate it if you made sure that they also get to partake of the free food. You can manage this by asking employees about food preferences or prohibitions ahead of time, ordering a variety of items so that everyone has at least one option, and listing the ingredients of the items that are brought in. Most restaurants should be able to accommodate a request for ingredient lists.
We would caution against asking specifically about food allergies since this could potentially rise to the level of a disability inquiry under the Americans with Disabilities Act, which could be unlawful in this instance. By asking generally about food preferences and prohibitions, you can accommodate not only employees who may have food allergies and sensitivities, but also employees who are vegetarian, vegan, or have religious restrictions on what they can eat.
This Q&A does not constitute legal advice and does not address state or local law.