Online food delivery applications have gained widespread adoption, offering users convenience and a diverse range of choices. However, many food delivery apps' current interfaces and feature sets do not sufficiently address concerns related to food wastage and nutritional transparency. This research focuses on evaluating and improving the user experience of food delivery applications using the User Experience Questionnaire (UEQ) and User Centered Design (UCD). Specifically, it aims to introduce customizable and standard portion size options and nutritional value information to mitigate food wastage and encourage healthier dietary practices. Additionally, the study proposes integrating a recommendation algorithm that employs collaborative filtering and machine learning to dynamically suggest portion sizes based on user behavior and preferences. Based on initial user interviews and subsequent surveys conducted with approximately 70 participants, key areas for improvement were identified and a prototype with enhanced features was developed. The User Experience Questionnaire (UEQ) results indicate an overall increase in user satisfaction, demonstrating the effectiveness of the proposed design. This study provides valuable insights for enhancing food delivery applications using Swiggy as a case study to more effectively address user requirements and contribute to sustainability goals. Furthermore, the study also proposes a filter feature enabling users to display only restaurants offering customizable portion sizes, further improving accessibility and promoting sustainability.