To facilitate the development of more effective promotional pathways for the "Year of Weight Management," this study adopted a 2 (information presentation format: video vs. text) × 2 (information delivery format: narrative vs. non-narrative) between-subjects experimental design, with 503 participants. Using a pre-posttest experimental approach, it explored the role of narrative transportation in influencing individuals' perceived social norms and behavioral intentions regarding low-sugar dietary behaviors. The results revealed a significant main effect of narrative transportation （F(1,499)=32.63，p<0.001）, along with a significant interaction between information delivery format and information presentation format. Mediation analysis showed that identification played a partial mediating role in the effects of both narrative videos and narrative texts on behavioral intentions. These findings suggest that narrative-based videos or articles can enhance individuals' sense of identification, strengthen their perceived social norms, and thereby increase their behavioral intentions.