Wireless body area networks (WBANs) is a special designed sensor network to connect various medical sensors for health which emerges as the natural byproduct of existing sensor network technology and biomedical engineering. In this paper, the tradeoff between the total power consumption and the end-to-end rate in non-homogenous relay environment for WBANs has been investigated. We consider such scenario involved two communication links, implant to body surface and body surface to off body. WCE emits RF signal from inside of human GI tract, the external AP that is designed destination to collect the transmitted bits by an on-body relay node which is placed on the belt of the human body. The energy consumption to deliver one bit and the end-to-end rate for the whole relay network is formulated. The total energy and end-to-end rate tradeoff has been studied with bandwidth, propagation distance and data rate for each link. The minimum energies over all possible data rate is obtained for different conditions.