Energy consumption in mobile ad hoc networks (MANETs) remains a critical concern due to the inherent limitations of battery-powered nodes. To address this challenge, researchers have turned to innovative approaches, such as the application of fitness functions to optimize energy consumption within the context of ad hoc on-demand multipath distance vector (AOMDV) routing protocols. The protocol proposed for this study is a modified version of AOMDV, known as fitness function AOMDV (FF-AOMDV). The fitness function serves as a guiding metric to determine the most efficient path from a source node to a destination node. This protocol aims to select paths that are not only reliable and timely but also energy-efficient. By incorporating the fitness function, the protocol can intelligently evaluate potential routes based on their energy consumption implications. The evaluation criteria encompass several key metrics, including energy consumption, packet delivery ratio, end-to-end delay, and network throughput. By quantitatively comparing these metrics, researchers can discern the advantages and disadvantages of each protocol in terms of energy efficiency and overall network performance. In summary, this research delves into the realm of energy-efficient routing in MANETs by introducing the FF-AOMDV protocol and the empirical evaluation carried out using NS-3.