The doctor is showing the app of gee

The challenge in this project was to find an innovative solution to overcome the overweight. Colombia (the magnificent place I was born) has serious problems, where more than half of adults (56%) are overweight. There are many solutions for this disease in different fields of expertise like nutrition, physical activity, mental health, and medicine. Unfortunately, current treatments provide little connection between those areas and the result doesn’t have a holistic approach. 

Gee app connects a multidisciplinary professional team with an overweight person to improve his physical and emotional state through a personalized treatment based on behavioral change strategies.

In this project, I conducted initial behavioral change research, user analysis, defined key personas, developed all the visual design, created all the interaction, and evaluated my design through usability tests with health experts.

Master Thesis Degree

Interaction design for behavioral changing focus on overweight treatment of young adults in Colombia​

My role

User Researcher, User Experience Designer, User Interface, Usability test​


2019 - 2020

Tools Used

Adobe XD, Adobe Illustrator, Photoshop, Adobe Indesign​

User Research And Competitive Analysis

Generally speaking, research on the influence of products in behavioral change is still in its early stages. However, as a UX designer, I strongly believe that understanding the customer decision-making process is a key factor to provide a solution that creates effective and positive experiences. I began researching behavioral design change methods and strategies and then integrated those concepts into the current interaction design process.

The next graphic shows the final result of the interaction and behavioral design process (the words in bold are the concepts taken from the behavioral change methods).

Subsequently, I evaluated 37 case studies, including projects and apps with a behavioral design change approach, and have good rates by its users in domains like transportation & logistics, smart environment,  social & personal, and healthcare.
As I was focused on healthcare I subdivided this domain into four subcategories: exercise, eat well, exercise & eat well, and mental health.

I analyzed each case study from different factors: motivators, rewards, and triggers.


The main problem address in this project is the overweight in Colombia, where one in three adults suffer from this issue, and the number has increased 5.2 % from 2010 to 2015.

I conducted interviews with 10 experts in different fields including nutritionists, physical trainers, psychologists, and sports doctors to understand how should be the treatment for a person with overweight. I realized that my assumption “users need to work only in the nutritional and physical area” was dead wrong. Sometimes a person can’t achieve his goal of losing weight because he doesn’t feel good with himself or has another sickness. Our wellness is a whole system that shouldn’t be treated by different components. 

Consequently, I developed an online survey based on the information collected from the experts with 200 young adults to develop a rich understanding of their eating, sleeping, activity habits, and problems.

The persona created was based on the results of the survey. I developed a journey map of my persona‘s normal day, identified key tasks, and found opportunities to develop the app wireframes to support her path of losing weight during the day.


The solution I provided to my persona’s requirements is an interactive and digital mobile app with personalized content that allows connecting a multidisciplinary overweight expert team such as a psychologist, nutritionist, physical trainer, and doctor with the person who wants to improve his physical, and emotional state

Additionally, behavioral change is encouraged through social status, points, and discount incentives.

From Findings To Features​​

The following wireframes are the final result of gee app after being evaluated by the health experts.


Left menu

Personal growth area

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Home: As a behavioral change strategy, social recognition is evidenced here where every person can share his achievements or ideas and prop others gee users.

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Left menu: All the elements of the different areas (nutritional, medical, phycological, and physical) are integrated to provide holistic treatment.

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Personal growth area: This is an example of an exercise for enhancing self-esteem. Sometimes it is hard to find positive things in ourselves, but with the help of our family, and close friends, you can discover it.

Feedback light

Photo feedback

Gee points

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Feedback light: Gee helps its users to understand how to make the right choices in their meals through a system light that classified the quality of calories in different colors.

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Feedback from a photo: To avoid the obsession of counting calories, the color system and the gee team guide the user with some recommendations based on what he is currently eating.

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Gee points: When a specific activity is completed the person earns points to motivate him and to reinforce that behavior. The points earned can be redeemed as discounts in some restaurants, supermarkets, and physical activities.


Gee is the result of exhaustive research and finding the connection between behavioral science, systemic design, and interaction design. This app provides expert guidance to support the treatment of an overweight patient and is focused on rewarding new healthy behaviors.

I developed this project alone, I learned new concepts, methods, skills, and I look forward to applying them to the next projects I will be working on.

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