Parts of a Meta-Study

This post continues consideration of the scientific literature surveyed by then-Ph.D. candidate Janna Stephens about eight years ago. The work includes a discussion of a meta-study (described in Stephens’s footnote #14) that was published by the International Journal of Behavioral Nutrition and Physical Activity.

The 10 authors looked at 41 studies that focused on the weights, physical activity, and nutrition of college students between the years 1970 and 2014. Sadly, only nine of the sources mentioned the use of online technology, and none made use of smartphones. Still, some helpful information could be gleaned.

In several studies, regular, basic phone texting had been part of the intervention methodology. The frequency of messaging ranged between five times a day and once a month. Some tried morning as the appropriate message time, while others tried evening. Some were automated, one-way communications, while others involved personal conversations with a mentor.

In a study where the mean age of the participants was 23, the people who received reminder messages about their goals lost significantly more weight, over a month, than the control group. In another study involving women between 18 and 30 years of age, automated daily messages did not make a significant difference in their improvement as compared to the control group.

In general

On the whole, it seemed clear that in the development of interventions that employ technology, the measurement of results should focus on weight, Body Mass Index, and waist circumference. (On the other hand, there is of course an entire school of thought which demotes the BMI from its former prominence.)

As an intervention, text messages alone, whether one per day or many, were not making much of an impression. Still, overall, the potential effectiveness of the tool appeared generally promising, if incorporated into a program that included other methods like education or group sessions.

Even back in 2015, when Stephens’s dissertation was published, there were around 17,000 health-related apps (not all having to do with obesity, of course). She noted that the new resources available to young people included “activity tracking capabilities and realtime feedback mechanisms.” Fortunately, by that time, a lot of healthcare professionals were up to speed on the new technologies, too.

In that era of experimental interventions, the idea of letting the subjects send messages was not popular. Stephens found only two studies where messaging was participant-driven, meaning that the subject could send a message and receive an immediate response. Only those two achieved “statistically significant results in at least one outcome.” People don’t want to just be told things; they want to be heard.

The Discussion section of Stephens’s paper went like this:

This systematic review revealed that text-messaging or smartphone applications are well accepted by participants and may provide beneficial effects on weight reduction, decreasing waist circumference, decreasing body mass index, decreasing fat mass, increasing physical activity, decreasing sugar-sweetened beverage intake, decreasing screen time, and encouraging healthier eating patterns.

Your responses and feedback are welcome!

Source: “Smartphone Technology and Text Messaging to Promote Weight Loss in Young Adults,”, July 2015
Image by Micah Drushal/CC BY 2.0

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About Dr. Robert A. Pretlow

Dr. Robert A. Pretlow is a pediatrician and childhood obesity specialist. He has been researching and spreading awareness on the childhood obesity epidemic in the US for more than a decade.
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Dr. Pretlow’s invited presentation at the American Society of Animal Science 2020 Conference
What’s Causing Obesity in Companion Animals and What Can We Do About It

Dr. Pretlow’s invited presentation at the World Obesity Federation 2019 Conference:
Food/Eating Addiction and the Displacement Mechanism

Dr. Pretlow’s Multi-Center Clinical Trial Kick-off Speech 2018:
Obesity: Tackling the Root Cause

Dr. Pretlow’s 2017 Workshop on
Treatment of Obesity Using the Addiction Model

Dr. Pretlow’s invited presentation for
TEC and UNC 2016

Dr. Pretlow’s invited presentation at the 2015 Obesity Summit in London, UK.

Dr. Pretlow’s invited keynote at the 2014 European Childhood Obesity Group Congress in Salzburg, Austria.

Dr. Pretlow’s presentation at the 2013 European Congress on Obesity in Liverpool, UK.

Dr. Pretlow’s presentation at the 2011 International Conference on Childhood Obesity in Lisbon, Portugal.

Dr. Pretlow’s presentation at the 2010 Uniting Against Childhood Obesity Conference in Houston, TX.

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