Location Initiated Individualized Texts for Adolescent Health (LIITAH)

Project start and end date: April 2018-April 2020

Excess weight puts millions of adolescents in the US at risk for weight-related illnesses and premature death, and disproportionately impacts Black and Hispanic populations. Excess weight (Body Mass Index (BMI) >85th percentile for age and sex) is the most common chronic illness among adolescents in the US, with 31.5% (over 7.5 million) affected. Black and Hispanic adolescents have a disproportional high prevalence of excess weight (Black 40%, Hispanic 38%, White 31%) and often have poorer treatment outcomes than their White peers. This has serious health consequences in youth and increases the risk of premature death as an adult from illnesses such as cardiovascular disease and stroke. In addition, excess weight in adolescence increases healthcare costs over their life course. As adolescence is a time when many habits are formed, it is important to address obesity in youth.

Adolescents consume 35% of their daily calories from meals prepared outside of the home – typically from restaurants. Research suggests that consuming foods prepared outside of the home is associated with a higher BMI. Black and Hispanic youth are more likely to be exposed to communities with high densities of fast food restaurants. We need ways to help adolescents make healthy choices in obesogenic settings that are relevant to, and have been tested in, populations who are at the highest risk for obesity and its associated costs.


  • Aim 1: Expand the program technology to work on all mobile operating systems, develop a companion application for parents, link locations and menu data for food outlets nationwide, allow remote message personalization, and test integration of the program into the Fruit Street platform.
  • Aim 2: Augment the message library to include messages and meal recommendations tailored to Hispanic adolescents and to parents (building on the current library that is tailored to Black and White adolescents).
  • Aim 3: Demonstrate the impact of using LIITAH on the main outcome of calories purchased from restaurants by adolescents, and the secondary outcomes of their visits to restaurants, and their body mass index (BMI).
  • Approach: A 6-month trial will assess statistically significant differences between intervention and control groups for calories purchased from restaurants (from photos of purchases cross-referenced with online nutrition data), geo-location data of visits to restaurants, and measured pre-post BMI.

Research Topics & Methods:

  • The program will be optimized for a) greater individual tailoring (design, message timing and learning features that will incorporate previous choices) that will be relevant to a diverse population including Hispanic and White families, b) additional engagement features (goal setting, rewards/point system), and c) dyad features for parents and adolescents to use together.
  • Participant advisory board made up of parents and adolescents will test iterations of the app and provide input regarding app design and interpretation of findings.
  • Message database will be prepared for commercial use and expanded to incorporate cultural preferences of 1) Hispanic adolescents, 2) parents (White, Black, and Hispanic), and 3) menu options for additional restaurants.
  • Trial will be conducted to test the impact of the LIITAH app on decreasing calories purchased from restaurants by adolescents, along with the number of visits to restaurants and the impact on their BMI.

This product will improve weight management efforts by providing personally relevant cues to action when they can immediately impact intake of high calorie foods. Other behavior change interventions will be enhanced by incorporating personally relevant messaging delivered at key times based on the users’ location.

This project is funded through a National Institute on Minority Health and Health Disparities (NIMHD) STTR R42 grant.


  • MEI Research Ltd.
  • Ken Resnicow, Ph.D.
  • David Córdova, Ph.D.
  • Acham Gebremariam, MS
For more information, please contact:
Associate Professor, Department of Pediatrics
NCRC Building 16, G028W
2800 Plymouth Road
Ann Arbor, MI 48109-2800


Project Manager:
Theresa Kowalski-Dobson, MPH

300 North Ingalls, Rm 6C09
Ann Arbor, MI 48109-5456

Phone: 734-232-2455
Fax: 734-232-1400
Email: tkowals@med.umich.edu