Yes—if the client offers, accepting a meal is generally considered professional and is common at events, especially weddings. Many photographers even address meals in their contracts, either as a requirement for longer bookings or as an option.

The key is that eating should never interfere with your work. If you accept, do it quickly, stay unobtrusive, and make sure you don’t miss important moments. For shorter 4–5 hour events, some photographers may simply bring snacks and water and only eat if explicitly invited, but accepting an offered meal is not unprofessional.

It also depends on the event circumstances. If the location is remote or you’re expected to stay for a long period, it’s even more reasonable for the client to provide food (and sometimes other logistics). In general: if the client says it’s okay, it’s okay—just handle it in a way that keeps your service professional.