Zest
Designing an app for easy product comparison by price, sustainability and nutrition

Role
End-to-End Designer
Tools Used
Figma
Figjam
Google Forms
Skills & Responsibilities
User Research
Concept Ideation
Interaction Design
Prototyping
User Testing
Timeline
2024 (Sep - Nov)
Designing a Sustainable Future
As part of my Interface Design, I created Zest, an app aimed at empowering users to make environmentally conscious food choices. The app’s goal is to make sustainable living accessible, exciting and empowering. The name Zest reflects the energy and enthusiasm the app brings to food sustainability.
The Problem📌
The global food system is broken. It’s causing massive environmental damage through greenhouse gas emissions, deforestation and water pollution, all driven by the production of meat and dairy.
At the same time, food insecurity affects millions, while others overindulge in unhealthy foods. This imbalance is harming the planet and creating a food system that’s neither sustainable nor equitable.
Double Diamond Approach

Research Questions
To better understand and address the challenges of food sustainability, I focused my research on the following questions:
Understanding User Perspectives
As part of my research, I conducted a survey and interviews to better understand the challenges individuals face in making sustainable food choices. The survey collected 62 international responses to get further analysis or exploration of individuals attitudes and behaviors towards sustainable food. In addition, I conducted 5 interviews with individuals based in Australia to capture more personal and localized perspectives.


Organizing the notes, quotes, and data from my research through affinity mapping.
Research Findings
Through a detailed analysis of both survey responses and interviews, I uncovered some powerful insights that highlight the key challenges individuals face when choosing sustainable food. These findings expose pain points and provide clear directions for designing solutions that empower users to make more sustainable food choices.
Nearly Half
85.5%
of respondents consider price as the biggest barrier
1 in 3
people emphasize the need for clearer labeling on sustainable food products
of respondents emphasized the need for better tools to help make more informed and sustainable food choices
The Goal
How might we make sustainable food options more accessible and appealing to a broader range of users by addressing price concerns, improving the visibility, enhancing trust of sustainability claims, offering comparative tools, and integrating engaging features to encourage informed choices?
From Idea to Concept: Wireframing the Foundation
After identifying the core challenges of the project, I began translating my ideas into early wireframes for Zest. These low-fidelity helped me establish the basic layout and functionality of the app, with a focus on the product comparison tool. This feature allows users to compare up to 3 products based on their features and sustainability attributes, providing an intuitive way to analyze products and make informed decisions.

I then refined these wireframes into mid-fidelity prototypes. The mid-fidelity version built upon the initial structure, offering greater clarity and interactivity. The stage was about fine-tuning the design elements, ensuring the app’s usability, and ensuring the key features, like the comparison tool and product selection, functioned smoothly.

Competitor Analysis: Finding Opportunity
While analysing existing grocery apps like Coles, I identified two key gaps:
Limited Sustainability Info: Coles provides basic sustainability labels but doesn’t offer comprehensive details on the environmental impact of products.
No product Comparison Feature: Users cannot directly compare multiple products based on sustainability attributes, which can make it more difficult to assess the best choice.
In contrast, Zest takes a more comprehensive approach by offering:
Advanced sustainability tools: In-depth environmental impact data of products.
A product comparison feature: Enabling users to easily compare sustainability attributes.
Interactive visualizations: Engaging ways to present sustainability data, helping users make informed choices.

Testing the Experience: Usability Insights
To ensure the app was user-friendly, I conducted 3 think-aloud sessions where participants verbalized their thoughts while completing key tasks such as selecting delivery methods, comparing products, adding items to the cart and finalizing checkout. This real-time feedback uncovered areas where users hesitated or faced challenges. I followed up with post-experience interviews to gather deeper insights and used the System Usability Scale (SUS) to quantify overall usability. Their feedback highlighted key areas for improvement, leading to refinements in navigation, product visibility and sustainability labels.
System Usability Scale Results


Identified Inconsistencies
Usability & Complexity
66.7% of users detected some inconsistencies within the system
100% of users found the system intuitive, though a few considered it somewhat complicated

After incorporating these changes, I ran a second round of testing with a heuristic evaluation from 4 diverse participants to ensure a broader range of perspectives. Their insights helped further optimize the app’s visual hierarchy, interactivity and user flow which results in a more intuitive and engaging experience for users.

Product Feature
Product Comparison
An interactive side-by-side comparison simplifies decision-making by allowing users to evaluate products based on price, reviews, sustainability attributes, product details, nutrition and packaging waste.
Flexible Shopping Options
Seamlessly choose in-store, delivery or pickup shopping from the homepage and select a preferred location, making grocery shopping more convenient and adaptable to their needs.
Search & Product Details
A search bar helps users quickly find the product they want and selecting a product provides detailed information for better decision-making.
Streamlined Checkout Process
Users can review their selected items before entering payment details, ensuring a smooth and informed checkout experience.
Design System

Future Learnings & Takeaways
The experience of working on Zest has been fulfilling and has improved my comprehension of UX/UI design principles:
User-Centered Design and Iterative Process: Through surveys and interviews, I gained a deeper understanding of users’ challenges with sustainable food choices. This reinforced the need to design based on user pain points. I was able to improve the product comparison tool’s usability and intuitiveness through usability testing and prototyping.
Spacing and Layout: One important takeaway was the need to carefully consider spacing to avoid clutter and enhance readability. By adjusting margins and padding, I improved the app’s layout, making it more user-friendly and visually appealing.
Typography and Hierarchy: I learned the importance of adjusting font weights and sizes to create a clearer hierarchy between headings and body text. This improvement helped make the content more scannable and improved overall readability.
WHAT'S NEXT?
As I reflect on the progress of Zest, I’m excited to explore:
How can I introduce personalized features to support users in achieving their specific sustainability goals?
What additional engagement strategies can I incorporate to keep users motivated to make more sustainable food choices?