Nibble: Food Logging Mobile App

A user research and UX design project for my final year dissertation.


For the first half of my final year project, I researched on a new concept for a mobile food logging app. My process started from user research and ideation, and ended with the creation of a prototype that was tested with a qualitative user study.

Aug 2015 - Nov 2015 (3 months, ongoing)
Individual Project supervised by Dr Brian Lim and Dr Zhao Shengdong
Persuasive Design, User Research, Prototyping, User Testing, Development
Pen and Paper, Photoshop, Invision, HTML/CSS/JS
The Problem

Death and disability from nutrition-related diseases is a very real problem we face. At some point in our lives, most of us have struggled with our diet.

We want to maintain a balanced diet, but there are many things we don’t know - what’s in our food? How much should we eat? How can we improve?

The Solution

I designed Nibble, a food diary and diet companion that guides people to work towards their health goals.

Key features of Nibble include:

Goal Setting

Nibble guides you on how much and what you need to eat, helping you set a daily goal.

Automatic Photo Logging

To ease the burden of manual logging, Nibble lets you log food by snapping a photo.

Personalized Insights

Nibble breaks down what you need to know about your meals.

Actionable Feedback

Timely suggestions on how you can improve your diet.
The Process

Research on users

To properly design Nibble, I first needed to understand the motivations and behaviors behind someone who would be using it. How will Nibble help them with their diet? What difficulties did they face? What do they need to know?

I read several papers on food logging and conducted an online survey to learn more about my potential users’ diet habits and previous experiences with food logging apps.

A survey on Google Forms I created for user research.

Defining user needs

From my analysis, I found that food loggers...
Find current food logging methods too tedious and time consuming.
Often forget to log their food, which leads to inaccurate insights and abandonment.
Feel guilty and discouraged when they cannot reach their goal.

So I decided that Nibble needed to address these issues.
Firstly, the food logging process needed to be efficient and streamlined.
Secondly, Nibble should remind the user to log, and account for forgetfulness when generating insights.
Most importantly, Nibble should never make the user feel bad for not reaching a goal, instead, it should be their motivational companion.

Literature review on persuasive design

Next, I read up on various models on effective goal setting and persuasive design to help me conceptualize features. For example, Fogg’s Behavioural Model (FBM) gave me insights on how I could motivate and help the user to take active steps to improve their diet.

FBM introduces several ways in which ability and motivation can be increased.
Photo credit: Kristen Sunde

Research on health and diet

I have to admit that I knew little about diet and nutrition - so I equipped myself with knowledge about food, diets and weight loss by reading papers on nutrition.

I read a Dietitian Manual to understand how professional dietitians help their patients and familiarized myself with the strategies they use to motivate them.

Competitive Analysis

After downloading 23 Android and iOS food logging apps, I went through their onboarding and logging processes. I created a table of their features, taking note of their ratings and downloads. I highlighted parts of the apps that were done well and where they were lacking.

Competitive Analysis Table

Feature Ideation

This involved translating all my existing research into functional features.

I brainstormed over 20 feature ideas, and listed pros & cons of each feature. Weighing them carefully, I picked the strongest features to implement.

Feature summary diagram of the main screens and functions

Lo-fi Wireframing

Next, I sketched the layout, flow and interactions on pen and paper. I laid them out on a Google Drawing, which allowed me to gather feedback quickly through comments.

View all my wireframes here - they're organized by feature!

Hi-fidelity Prototyping

Once I finalised the wireframes, it was time to materialize them in a high fidelity prototype. You can try it at The Outcome. For this, I used Photoshop to create hi-fidelity mockups and animated them with Invision.

Making an interactive prototype on Invision

Efficiency Analysis

I wanted to determine how fast the logging process was in Nibble. So, I used Cogtool, a predictive performance modeling tool, to help me predict the time taken to go through the screens and complete the task.

I tested it against MyFitnessPal’s logging process, and Nibble was 5 seconds or 33% faster! The logging process on Nibble was more efficient than MyFitnessPal’s, the most widely used logging app with over 50 million users.

Speeds of the logging processes - 14s (MyFitnessPal), 9s (Nibble). Nibble is much more efficient.

Pilot User Study

With the high fidelity prototype, I conducted a qualitative think-aloud study with follow-up interviews. 5 participants were involved. The experiment set out to test Nibble’s motivational qualities, usability and usefulness.

Preparation - I came up with a hypothesis for each feature and constructed user tasks and interview questions that would help me test these hypotheses.
Think-Aloud Process - Next, I asked my participants to carry out these tasks, encouraging them to say whatever went through their heads. I wrote down my observations and interviewed them afterwards.
Base of Comparison - I also wanted to compare Nibble with the most popular food logging app, MyFitnessPal, so my participants logged food on both MFP and Nibble, giving their thoughts on both.

Results and Data Analysis

I carried out a thematic analysis on the user responses, by coding each theme with a color. I sorted them according to 1) Findings 2) Usability Issues and 3) Thoughts and Feelings


Once again, I was reminded of the importance of user testing, because of these interesting (and some surprising) findings.
Participants felt that actionable and specific suggestions that told them exactly what they should do were particularly useful.
They also preferred more immediate suggestions, like something telling them what they should eat immediately after logging a meal.
Participants’ existing health motivations affected their willingness to commit.
Parcipants disliked seeing their unhealthy meals, citing guilt as the main reason.

These findings will help me shape my next iteration, and that's why it was critical to test with users.

Usability issues

I detailed usability issues and assigned a severity rating to each one (using Nielsen’s guidelines). I wrote down ways in which I could solve these issues.

Above is part of the Usability Assessment Report I did.

Thoughts and Feelings

All participants felt
Nibble would be useful for their diet
The interface was easy to use and understand
Motivated when they used the prototype
They highly preferred Nibble's food logging interface to MyFitnessPal’s.


The first half of the project is finally finished! I feel that the biggest challenge was to complete the research, design and testing in 3 months, while taking other college courses concurrently. Preparing for project reports, presentations and ethical research reviews took up a third of this time.

I started with little knowledge on health, diet and persuasive design; it was a race against time right from the start.

However, I am immensely pleased with the outcome of my efforts, especially after hearing good feedback on my prototype! The research knowledge I gained is definitely a notch on my belt :)

The Outcome

Try out the hi-fidelity prototype! These are the Onboarding Process and Food Diary respectively.

What's next?

I was given the green light by my evaluators to further develop Nibble. So, I will be spending the next few months developing a fully functional hybrid mobile application, and evaluating it once again with more users. This project is only halfway done. Do stay tuned for more updates!