Project Summary

This research project is in progress. PCORI will post the research findings on this page within 90 days after the results are final.

What is the research about?

Health literacy refers to patients’ ability to understand basic health information to make health decisions. Parents with low health literacy may have trouble learning steps to promote healthy weight gain in their babies and prevent childhood obesity. For example, parents may not know the benefits of breastfeeding, how to mix formula correctly, or how to interpret food labels. They may not know that gaining too much weight quickly as a baby can cause health problems later in life.

In this study, the research team is comparing two ways to promote healthy weight gain and help prevent obesity. The first way is a program called Greenlight. Greenlight targets parents with low health literacy but is designed to help families of all literacy levels. At regular office check-ups, doctors trained in the program review health education booklets with parents. The booklets focus on breastfeeding, diet, physical activity, and parenting. Doctors help parents set goals around these behaviors.

The second way is called Greenlight Plus. In Greenlight Plus, parents receive the Greenlight program plus information to reinforce healthy behaviors between doctor visits. For example, parents get access to the Greenlight website and regular text messages on setting and reaching behavior goals that promote healthy weight gain for babies.

Who can this research help?

Results may help clinics when considering ways to help parents raise healthy children.

What is the research team doing?

The research team is recruiting 900 English- and Spanish-speaking parent-infant pairs from six primary care clinics. The team is assigning the pairs by chance to receive either Greenlight or Greenlight Plus for two years. At the start of the study and throughout the child’s first two years of life, the team is interviewing families and reviewing medical records to see how each baby is growing. The team wants to know how Greenlight and Greenlight Plus compare in promoting healthy weight gain for different groups based on language, race, ethnicity, and health literacy.

Families, clinicians, and experts in health communication helped design the Greenlight program. They are also helping to plan and conduct the study.

Research methods at a glance

Design Element Description
Design Randomized controlled trial
Population 900 parent-infant dyads 
  • Greenlight
  • Greenlight Plus

Primary: weight-for-length trajectory

Secondary: body mass index z-score trajectory, weight-for-length z-score trajectory, overweight and/or obesity, family-reported beliefs and behaviors, family satisfaction with care, perception of health communication quality

Timeframe Timeframe Length of follow-up for collecting data on primary outcomes. View Glossary 2-year follow-up for primary outcome 

Conflict of Interest Disclosures

Project Information

William J. Heerman, MD, MPH^
Vanderbilt University Medical Center
Greenlight Plus Study: A Randomized Study of Approaches to Early Childhood Obesity Prevention

Key Dates

December 2018
March 2025

Study Registration Information

^Russell Rothman, MD, MPA was the original Principal Investigator on the project.


Has Results
Health Conditions Health Conditions These are the broad terms we use to categorize our funded research studies; specific diseases or conditions are included within the appropriate larger category. Note: not all of our funded projects focus on a single disease or condition; some touch on multiple diseases or conditions, research methods, or broader health system interventions. Such projects won’t be listed by a primary disease/condition and so won’t appear if you use this filter tool to find them. View Glossary
Populations Populations PCORI is interested in research that seeks to better understand how different clinical and health system options work for different people. These populations are frequently studied in our portfolio or identified as being of interest by our stakeholders. View Glossary
Intervention Strategy Intervention Strategies PCORI funds comparative clinical effectiveness research (CER) studies that compare two or more options or approaches to health care, or that compare different ways of delivering or receiving care. View Glossary
State State The state where the project originates, or where the primary institution or organization is located. View Glossary
Last updated: April 15, 2024