Evaluating function availability and user satisfaction with nutrition apps: user-generated content analysis and text mining study

Nutrition apps are increasingly used to support dietary self-management and health promotion. However, how app functions align with nutrition-related tasks and user satisfaction with these apps remain unclear. Evidence from cross-country comparisons is limited. This study aimed to compare function availability and user satisfaction of nutrition apps in China and the US and to examine key factors associated with nutrition app satisfaction in different market contexts. A large-scale review-based analysis was conducted using nutrition app data from major app stores in China and the US. Task–Technology Fit, Latent Dirichlet Allocation, the Two-Factor Theory, the KANO model, DeepSeek-R1, and the Analytic Hierarchy Process were combined to assess function coverage and satisfaction patterns. A total of 269,300 reviews from China and 455,245 reviews from the US were included. Chinese nutrition apps showed broader coverage in target monitoring (n = 111, 84.73%) and nutrition education (n = 101, 77.10%), while US apps focused more on dietary behavior intervention (n = 364, 89.66%). Both countries showed clear gaps in personalized nutrition services. KANO analysis showed that all identified factors in China were classified as charm attributes, whereas in the US both charm and essential attributes were identified. AHP-based results indicated that overall user satisfaction was higher in China (0.8901/1) than in the US (0.8372/1). In the US market, dissatisfaction was primarily associated with issues related to the food database (0.7217/1) and fee (0.6795/1), whereas Chinese users more frequently reported concerns regarding reliability (0.7725/1). User satisfaction with nutrition apps differs between China and the US in functional focus and expectation structures. Improving system reliability in China and optimizing core functions and pricing in the US, alongside strengthening personalized services in both contexts, are key to enhancing user satisfaction and intervention effectiveness.