Health behavior theory has been championed as an important basis to understand the processes and mechanisms that underpin health behavior and an important guide to behavior change intervention. However, the sheer number of available theories and models, each with their associated constructs and mechanisms, presents considerable challenges to researchers and practitioners and researchers on which theory is likely to have ‘best fit’ with their research questions and to guide practice. Recent expert-consensus research identified 83 theories of behavior change. There has also been research identifying considerable redundancy in the constructs and content of these theories. This points to the need for more uniformity and consensus in the core constructs and related mechanisms of behavioral theory, which may help focus research and practice. Yet, such uniformity could stifle creativity, as researchers and practitioners may focus on established theories and be reluctant to explore other potentially fruitful avenues. In this session, leading researchers with contrasting perspectives will debate this key issue: that advancements in behavior change research and practice is being held back by the large number of available theoretical perspectives.