A gas turbine including a fan platform positioned between adjacent fan blades of a fan of the gas turbine engine is provided. The fan platform defines an outer surface that at least partially defines an inner flowpath boundary of the fan. Additionally, the fan platform includes at least two components attached to one another. At least one of the components of the fan platform defines an enclosed void. An insert is positioned within the enclosed void formed of a material defining a relatively low Young's modulus. The insert may prevent resin from filling the enclosed void during assembly/manufacture of the fan platform, while also reducing a weight of the fan platform and an amount of stress on the fan platform.