weight loss maintenance

A trial determines if a mobile app can induce behavioral changes and increase vegetable consumption in overweight individuals to help weight loss maintenance.

A diet rich in fruits and vegetables is known to lower the risk of developing cancer, cardiovascular disease, and stroke and lower overall mortality. However, only 43.9% of Canadians over 12 years of age reported consuming five or more servings of vegetables per day.1 In fact, most Americans consume a dismal 1.7 servings of vegetables per day.  Health interventions that can induce behavioral changes to promote weight loss or help in weight loss maintenance are difficult to scale to entire populations. However, mobile apps can be used to encourage the adoption of healthy behaviors on a mass scale. Although a number of health-promoting mobile apps are available, these have not been tested rigorously in clinical trials.

Recently, a group of researchers from Stanford University carried out a pilot study in which 17 overweight adults aged 42 years were randomly divided into the two groups, and the intervention group was asked to use an automated mobile app called Vegethon, which monitored vegetable consumption, set goals, provided feedback, and enabled social comparisons.2 The study found that the app was highly effective in increasing vegetable intake, with the mean difference in vegetable consumption between the control and the intervention groups at the end of 12 weeks being 7.4 servings. However, the sample size was small, and therefore, a study with a larger number of participants was necessary to attest the veracity of their findings.

The same group of researchers together with collaborators from the University of Cambridge undertook a study with a larger group of overweight individuals. Their findings were recently published in the International Journal of Behavioral Nutrition and Physical Activity.3 The study involved 135 overweight adults aged 18-50 years who were recruited from an ongoing weight loss trial and randomly assigned to either the Vegethon app group or the control group. The Vegethon app allowed for goal setting and goal monitoring of vegetable consumption and encouraged behavioral changes by introducing elements of competition, fun, surprise, choice, and control. Participants in the intervention group were asked to use the app for at least 1-2 minutes per day.

Eligible participants had a BMI of 28-40 kg/m2, did not have cancer, liver, kidney, or heart disease, were non-diabetic and non-hypertensive, and had either an iPhone or an Android phone. Information on daily vegetable intake was collected using a questionnaire at eight weeks. Information on daily vegetable intake was also collected using a 24-hour dietary recall questionnaire at five weeks.

They found that the use of the Vegethon app increased daily vegetable consumption significantly. Based on the data collected at eight weeks, those using the app consumed an average of two more servings per day compared to the control group. Based on the data gathered from the 24-hour dietary recall at 5 weeks, those using the app consumed an average of one more serving per day compared to the control group. No differences in consumption were observed for food groups not targeted by the app. Notably, those who consumed more vegetables at baseline also consumed more vegetables with app usage.

This study is the first to rigorously test the efficacy of a health app in promoting vegetable consumption. The results of the study demonstrate that a health app that can be personalized, engages with the user daily, and offers timely feedback can effectively encourage healthy behaviors, helping to promote weight loss and weight loss maintenance. Importantly, the efficacy of the app was demonstrated in a group of participants who were part of a weight loss trial and already motivated to adopt healthy eating behaviors. Further testing of the app is required to demonstrate its efficacy in the general population.

Written by Usha B. Nair, Ph.D.


1) Statistics Canada. Fruit and vegetable consumption. http://www.statcan.gc.ca/pub/82-229-x/2009001/deter/fvc-eng.htm. Updated: September 28, 2016. Accessed: September 24, 2017.

2) Mummah SA, Mathur M, King AC, Gardner CD, Sutton S. Mobile Technology for Vegetable Consumption: A Randomized Controlled Pilot Study in Overweight Adults. JMIR Mhealth Uhealth. 2016 May 18;4(2):e51. doi: 10.2196/mhealth.5146. PubMed PMID: 27193036; PubMed Central PMCID: PMC4889871.

3) Mummah S, Robinson TN, Mathur M, Farzinkhou S, Sutton S, Gardner CD. Effect of a mobile app intervention on vegetable consumption in overweight adults: a randomized controlled trial. Int J Behav Nutr Phys Act. 2017 Sep 15;14(1):125. doi: 10.1186/s12966-017-0563-2. PubMed PMID: 28915825; PubMed Central PMCID: PMC5603006.

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