Lipids are a crucial factor affecting the quality of meat analogues (MAs). However, there have been no reports on the study of fatty acid (FA) chain length in MAs. Therefore, this study evaluated the effects of different chain length FAs (lauric acid, myristic acid, and stearic acid) on the quality and structure of soy protein isolate (SPI), hemp protein (HP), and wheat gluten (WG) extrudates through methods such as texture, LF-NMR, and SEM. Compared with the control group, as the FA chain length decreased, the hardness and chewiness gradually decreased, and the elasticity gradually increased, especially the lauric acid elasticity increased from 92.51 % to 96.87 %. Compared with the other two FAs, lauric acid enhanced the hydration ability of the extrudate and promoted the formation of intermolecular hydrogen bonds. Overall, the longer the FA chain length, the less it affects the texture and the greater its impact on the fiber structure.