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Despite considerable evidence to support efficacious and effective intervention for single health behaviors, relatively little is known about simultaneous multiple health behavior change. This research analyzed multiple health behavior change for three very different health risk behaviors. The sample (N=9,461) was predominantly White (93.8%), middle-aged (X= 43.9 years-old, SD=10.74) adults who met criteria for smoking, unhealthy diet, and unprotected sun exposure. Specifically, when sun protection and diet, smoking and diet, and smoking and sun protection were analyzed as three sets of behavior pairs from baseline to 24-month follow-up, results consistently demonstrated that simultaneous intervention on multiple health behavior risks increased the likelihood that participants moved to criteria on both behaviors. More specifically, across all the behavior pair analyses and treatment conditions, 70 out of the 71 odds ratios revealed that participants were more likely to meet criteria on both behaviors compared to participants who only met criteria on the second behavior. Overall, results provide empirical support for the advantages of simultaneous intervention for multiple health behavior change as paired action, co-progression, and reduction on severity was observed across treatment conditions. Finally, results provide empirical support for shifting the fundamental unit of analysis from separate behaviors at outcome to behavior pairs at outcome and to use dynamic variables to help elucidate the science of behavior change.