The rapid expansion of smartphone‐based diet applications has been driven by the growing prevalence of mobile technology among consumers and their diverse lifestyle preferences. This study seeks to analyze the factors influencing the use of these applications. The conceptual framework combines three models: the unified theory of acceptance and use of technology (UTAUT2), the DeLone and McLean information system (IS) (D&M IS) success model, and the protection motivation model. Conducted in Saudi Arabia, the research employed a quantitative methodology with a survey questionnaire administered to 572 customers. The study, validated through partial least squares (PLS) structural equation modeling (PLS‐SEM), identified several significant predictors for the intention to use smartphone diet applications. These include performance expectancy (PE), effort expectancy (EE), social influence (SI), price value (PV), IS, and service quality (SEQ), as well as perceived vulnerability and perceived severity. Contrary to expectations, factors like facilitating conditions (FCs) and hedonic motivation (HM) did not significantly impact behavioral intention. This pioneering study sheds light on the adoption of smartphone diet applications in an emerging economy, offering valuable insights for scholars, developers, and health professionals.