Maintaining security in wireless systems has been a challenge due to the broadcast nature of wireless communication channels. Many methods have been proposed as countermeasures to eavesdropping attacks, which stand as one of the most important secrecy attack types that use the vulnerabilities of wireless channels. The majority of these methods come with the cost of additional power consumption for maintaining secrecy. In order to provide a framework that can enable a tradeoff between energy efficiency and secrecy, we provide a flexible adaptive physical layer security approach that enables tunable security levels for distinct bit streams of a single user. Our main motivation stems from the fact that not all data bits within a single bit steam require the same amount of security. The proposed adaptive power optimization framework allows the assignment of different secrecy rate constraints for distinct data streams. Via simulations, we show that the proposed approach can increase the power efficiency compared to the non-adaptive physical layer security solution, while satisfying the required secrecy constraints.