Regulatory focus (Higgins, 1997) and self-determination (Deci & Ryan, 2000) are two motivation theories widely applied in health-intervention research but never conjointly, despite sharing a number of theoretical similarities. In three studies (N = 578), we investigated how university students' self-determination motives to act upon their nutrition interact with induced regulatory focus and regulatory-message framing to predict their behaviors or intentions to improve their eating habits. Results revealed a fit between extrinsic motives and prevention focus: Intention increased with extrinsic motives in a prevention but not a promotion focus. The effect of intrinsic motives, however, was independent of the focus, which suggests that these motives drive intention and behavior independently of external cues. Hence, the results advocate for simultaneously taking into consideration self-determination and regulatory focus when planning a health intervention relying on motivation. (PsycINFO Database Record (c) 2019 APA, all rights reserved).