A mobile phone app has shown what, where and when people consume.
Credit: Artwork: Jamie Simon, Salk Institute; Data: Shubhroz Gill and Satchidananda Panda
Scientists used a mobile phone application to collect data about daily food and drink intake from over 150 participants over a 3-week period, with fascinating results.
Satchidananda Panda, senior author of the current study and associate professor at Salk Institute, specializes in investigating the links between people's circadian rhythm (or body clock) and health. His work focuses on how the body's genes, molecules and cells "keep the whole body on the same circadian clock."
The stated aim of the project was to pilot a way to objectively study the effects of timing food intake in humans, and then to assess whether reducing the daily duration would affect health. However, the medium of data collection allowed more than this to be revealed.
Panda and first author Shubhroz Gill, a postdoctoral associate in Panda's group, hypothesized that a timed feeding schedule could prevent "metabolic jet lag," when the body's circadian rhythms become distorted due to irregular eating times, or changes in habits - for example, between weekdays and weekends.
They decided to use the app for research after noting a lack of published research regarding eating times.
Panda's lab had previously found that changing eating duration in mice could help prevent obesity and disease.
An app to record people's eating habits
Gill and Panda designed an app to collect, analyze and interpret people's food intake patterns. People would send pictures of anything they ate or drank, from a whole bottle of water to a few bites of a cookie, for analysis. The app also captured metadata, such as where the food was eaten, and a timestamp. Reminders were sent daily to participants.
Volunteers ages 21-55 were invited to register for the study through online and print advertisements in the San Diego area. Having visited the lab to sign a consent form, they were given access to a free mobile research app, through which they were to take and submit photos of everything they ate over a period of 3 weeks. The participants should not have been on any food management or weight loss program for the previous 6 months.
Data collected via the app showed that most people eat over a period of 15 hours or longer each day, consume less than 25% of their calories before midday and more than 33% of their calories after 6 pm.
Finding that most people consume food for 15 hours or longer in a day took the researchers back to their original question: might the app help some people to be healthier by encouraging a time-restricted feeding period, in other words, for fewer and more consistent hours each day?
To test this, they selected eight overweight individuals who used to eat for more than 14 hours a day to eat for a 10-11 hour period instead, without any recommendations for changing their normal diet. They also had access to a "feedogram," which provided information about their intake.
After 16 weeks, they had lost an average of 3.5% of their excess body weight and all reported "feeling more energetic and having slept better."
This suggests that eating over a shorter period could help improve wellbeing, at least for some people.
Novel medium adds new dimensions to data
The researchers were encouraged by the participants' enthusiasm with this novel method of research and the added dimensions of metadata gathered.
Information about the locations of food consumption was revealed through backgrounds of the images. People consumed food in a range of places, from gas stations to sitting in bed. This kind of incidental data would not have been collected if mobile technology had not been used.
Similarly, a cultural dimension was revealed through the mobile app medium. The data showed that Americans prefer milk or coffee in the morning, tea during the day and alcohol in the evening. Yogurt was mostly eaten in the morning, whereas sandwiches or burgers were favored at lunchtime. Vegetables and ice cream were more likely to be consumed in the evening. Chocolate and candy was recorded from 10 am onward.
A further role for the app, suggests Gill, could be in the implementation of personalized medicine strategies. It was noted that 2 out of 3 participants were taking supplements, but at different times of day. Use of both supplements and medications could be tracked in this way for analysis.
Overall, Panda says:
"The study is about developing methods and offers some preliminary insight into what and when people eat. One should not take away the message that changing the eating duration is the only method to improve health. This may also be risky for individuals with undiagnosed fasting hypoglycemia."
The researchers suggest that larger studies, reflecting the differences in habits between shift workers or people from different socioeconomic groups would be useful to discover more variations. Panda also hopes to test the benefits of time-restricted feeding under different conditions of sleep, activity and disease.
The smartphone app is available for anyone willing to contribute his/her data to a Salk Institute IRB-approved study. Visit myCircadianClock.org and download the app "myCircadianClock" from the iOS App Store or Google Play. The app will help record intake of food, water, beverages and supplements and, after 2 weeks, reveal the user's own "feedogram."
In September 2014, Medical News Today reported on research showing that infant eating habits may predict eating habits later in life.