1. How mobile phones can promote
vegetable consumption
Stephanie Carter and Neema Moraveji
“Tomatoes are NOT veggies!”
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

2. Executive summary
10 people (moderate to healthy eaters age 25-35) tracked their veggie-eating habits
by taking photos of their meals with their phones. There were two conditions:
– Individual (take photo, get feedback)
– Team (Two 3-person teams that competed within the team as well as against
the other team)
Other variables were also varied as an experiment:
– Image-based feedback about consumption status once vs. twice a day
– Showing daily score of one team to the other
– Phrases on feedback images encouraging them to eat more, etc.
Results
People over-predict the number of veggies they eat. The reality is that people only
ate about 2 veggie servings per day.
Social feedback, as compared to individual conditions, led to:
– improved engagement
– larger predictions about vegetable consumption habits
Counting portions, rather than calories, is a promising direction.
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

3. The Interface
Your lunch: 3 veggie portions! Nice!
Today: 3 veggie portions, 80% of rec. 3rd place today.
Concept 1 Concept 2
Different food groups, amount consumed, single Veggie-only, portions, social vs. individual.
iconic representation of food group
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

4. How it
worked
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

5. Taking photos of food? Really?
Taking a photo of your meal (a growing practice) has been shown to improve
eating habits in a recent university study.
Using human-based computation, data can be extracted from photos. This has
been done with google image labeler but hasn’t been applied readily to food
data.
VeggieMagic participants said that photographing food was not difficult or
socially awkward.
Photos can be sent/recvd over MMS or Email.
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

6. Recruiting and instructing participants
http://www.youtube.com/watch?v=7lUpRnWIR-c
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

7. Communicating with participants
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

8. Consumption behavior data
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

9. Consumption
behavior
visuals
(of one
participant)
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

10. Results
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

11. Results
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

12. Survey feedback by phone and email gave
insight into user behavior and reactions
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

13. How did you feel when
a veggie you had eaten
was not accounted for?
I felt like I had been slighted! I felt like
something was wrong with the
"system" and I felt like I wasn't being
rewarded. It made me trust the
system less but I also noticed that I
How did you feel when really wanted to get the "credit."
you discovered certain
foods were not counted
as veggies? I felt like Homer Simpson. I thought
I knew what my veggies were.
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

14. Findings: User interface
People anthropomorphize the service very quickly.
Getting ‘human’ feedback (e.g. “Nice job! 3 veggies in one meal!”) was motivating.
Not always clear what veggie-icon mapped to what portion of the user’s photo.
Nice that it didn’t require any app installation.
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

15. Findings: Social interaction
It isn’t as socially awkward to take photos of your food as was predicted. It’s common, actually.
How would teams form? We put 3 friends together for one team and another team with 1
almost-stranger and a boyfriend/girlfriend couple in it.
When you don’t know your team members, social feedback wasn’t as impactful. When you
know them, it was very impactful.
Seeing the status of the other team was motivating.
“Didn’t want to let the team down.”
“I have a competitive side.”
Accountability: to your group, to your self. But accountable to yourself is less strong unless
there were longer term goals and some progress is shown over time.
Nobody asked for calories, fat, etc.
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

16. Findings: Consumption behavior
All participants predicted they would eat more veggies than they actually ate.
On average, participants ate just over half as many veggies as they were asked to eat (asked for 4,
they ate 2). Over the course of a week, people only eat about 15 portions of a veggies.
Diversity in vegetable-eating seemed to increase over time.
Disproving our hypothesis, there is no “significant” difference between veggie consumption in lunch
and dinner. We hypothesized dinner would have more because feel they have to ‘catch up’.
The ‘social’ condition (6 team users) predicted and ate more than the individual group.
Smart adults don’t know what foods are vegetables vs. fruits, grains, or berries (avocados, tomatoes,
corn and olives are confusing). VeggieMagic helps them understand.
The average number of veggies eaten per meal overall: 2.51
For individuals: 2.33
For team members: 2.72
data The avg number of veggies predicted eaten per day, overall: 3.5
summaries for For individuals: 3.25
For team members: 3.8
11 participants
Lunch average: 1.3
Dinner average: 1.2
Lunch total: 72
Dinner total: 66
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

17. Findings: System
Doing this by hand is not scalable.
It works equally well with Blackberry or iPhone.
After an interview with a nutritionist, she seemed to think it would be feasible to have nutritionists label
veggies in the images.
Tracking strange (non-foods) is hard - this aspect needs refinement.
Only tracking veggies may be limited in the long term - perhaps in the future we should expand to
track all food groups?
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

18. What’s next?
We are planning a design-based research project over the summer to study:
1) photo-based data collection
2) social presence
3) portion-based measurement... how can it be used to improve dietary habits?
We are recruiting a tech lead to build out the system.
Our goal: run 100 people in August to answer our “open questions” [see appendix]
Submit to ACM IUI 2011 (Sept. 2010 deadline).
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

19. Appendix
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

20. Open questions
Do we have to be more direct? Will self awareness of veggie consumption ultimately drive
behavior change? Does this hope fall into the trap of believing that ‘information should drive
behavior change’? Do we need more specificity? i.e. [text--> “eat a pepper right now”] or
[Carrot Mondays- carry a carrot around with you all day. Eat it if you wish.]
Do we need to display a direct mapping between meal and detected veggies? Do we
need to show people exactly how many veggies came from each meal? Do we need to have
a specific icon for “spinach” or can all “green leafy veggies” be represented by a single icon?
• Is this sustainable? Would it have the same impact over time or would you get sick of it? Is the goal
to continue using it?
• How should social work? Should we do collaborative or competitive social feedback? (between- or
within-teams) How will teams be formed?
• How to deal with data-collection problems? How should the photo-taking work? Can you clarify an
image with optional text? What if you forget to photograph and you ate your meal? How does error-
correction work? How do send data if photo is impossible?
How should triggers work? A trigger twice a day might get annoying/invisible. Do we make
“smart triggers” that remind you when you haven’t send photos recently?
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

21. Theoretical Justifications
Motivation
• acceptance, fear- awareness of what i eat, how i compare to friends, and
how my eats compare to recommended eats
• hope - my consumption is not just about numbers- I am what I eat is visually
represented and gives me a picture of how i could improve my wellness.
• pleasure - It is funny, and approachable information, acting on which might
lead me to feel better
Trigger
• spark - request for input of daily photo of dinner or lunch
• facilitator - receipt of daily visuals of self and friends
• facilitator--> signal - cumulative visualization of my monthly consumption,
on my fridge, or on my computer desktop.
High Ability - The simplicity factors are:
• brain cycles are reduced (no calorie counting)
• time is reduced (only quick input needed from user, not time to analyze)
• physical effort is reduced (use one hand to take quick photo of meal)
• socially acceptable (people think you’re just texting when you take photo of
food. also, your friends are your teammates, so it’s fun)
• routine (smart phoning- texting, checking email- is already a common
complement to mealtime)
• money (information is free)
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

22. Initial user feedback that guided roll-out
ACTIONABLE:
I want it compared to what a healthy diet is.
see progress over time- competing against self
What about a sandwich?
What about snacks?
Individual or social? Trusted friend circle only?
FULL LIST:
“[if] i have to send my girlfriend this info, maybe i’ll get a salad instead.”
“I might not like results but think it could be interesting. would depend on how it was displayed. i wouldn’t want it to just be abstract,
like here’s what you ate, or here are calories. i want it compared to what a healthy diet is. want to know where i’m off and where ok.
eg: fine on carbs and veggies but bad on saturated fat. i need a benchmark.
“i want to be able to see progress over time- competing against self.
“It would be cool is if you could link up the data to restaurants in my area. You need to eat more of x, and here’s some places where
you could get x within your budget.
“What about a sandwich? How do you know what veggies are in there?”
“I snack a lot. Each time?”
“The link to friends puts me off a bit. it’s good in theory but i don’t think i’d use it. maybe if i was more proud in my eating habits i might
like it, but i find it invasive and don’t think i would want that. i prefer seeing my own progress. i already know friends eat more than
me. I don’t think my friend will keep me accountable but someone you’ll live with might, like girlfriend. but still ultimately prefer to do it
alone. if it’s just internal, it might be easier too.
“I already self-monitor myself by looking and thinking about my garbage. I’d love to see a visualization of all my garbage. I like the
idea of showing that concept with food and veggies.”
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu

23. Related work
Photographing meals 'could help weight loss'
Taking a photograph of your meal before you eat it can encourage weight loss, a new study suggests.
Slimmers began to eat healthier food when they were asked to take a picture of what they were eating, scientists found.
http://www.telegraph.co.uk/health/2674514/Photographing-meals-could-help-weight-loss.html
http://www.daviddeal.info/research/photodiaries.shtml
http://shareurmeal.com/
Stanford University, Spring 2010
CS377v - Creating Health Habits
habits.stanford.edu