Results Summary

What was the research about?

Obesity can lead to serious health problems such as diabetes and heart disease. Doctors often have limited time to provide weight loss support during clinic visits.

In this study, the research team wanted to learn if a weight loss program offered at clinics, called the intensive lifestyle intervention, or ILI, helped patients lose weight. In ILI, patients worked with trained health coaches. The team compared patients in ILI with those receiving usual care.

What were the results?

After two years, compared with patients receiving usual care, patients in ILI

  • Lost 4.5 percent more weight and lost 4.5 more kilograms
  • Lost five more centimeters from their waist
  • Had lower total cholesterol and higher healthy cholesterol
  • Had improvements in some aspects of quality of life, such as self-esteem, sexual life, work, and fatigue

The two groups didn’t differ in blood pressure, unhealthy cholesterol, fat levels in the blood, how satisfied they were with their health care, and other aspects of quality of life such as pain or sleep.

Who was in the study?

The study included 803 patients with obesity. Of these, 67 percent were African American, 26 percent were White, and 7 percent reported another race. The average age was 49, and 84 percent were women. All received care at one of 18 primary care clinics in Louisiana.

What did the research team do?

The research team assigned clinics by chance to offer ILI or usual care. In ILI, patients met with health coaches in person or by phone. Coaches worked with patients to create short-term goals and action plans. Patients could also attend at least 40 education sessions with health coaches. The sessions were weekly for 6 months, then monthly for 18 months. Session topics included exercise, stress management, and portion control. Patients in ILI received a pedometer, a scale, a meal plan, and pre-packaged meals in the first month of the study and as needed for the rest of the study. Using an online system, the team gave patients and coaches real-time feedback about weight loss and daily goals. Also, patients’ doctors attended an education program about helping patients manage their weight.

Patients receiving usual care had regular visits with their doctor and received three health information newsletters each year.

Patients took surveys about managing their weight and had in-person visits to assess weight and other outcomes at the start of the study and again 6, 12, 18, and 24 months later.

Three patient advisory boards gave input on the study.

What were the limits of the study?

Most patients were women. Two clinics had fewer patients than the other clinics in the study. Results may have differed if more patients at these clinics took part in the study.

Future research could test ILI in other locations.

How can people use the results?

Clinics and health insurers can use the results when considering ways to help patients manage their weight.

How this project fits under PCORI’s Research Priorities
PCORI identified obesity as an important research topic. Patients, primary care clinicians, and others wanted to learn: Which treatment options achieve the best weight-loss outcomes for adults, especially those who are from minority racial/ethnic groups, have low socioeconomic status, or live in rural areas? To help answer this question, PCORI launched an initiative in 2014 on Obesity Treatment Options Set in Primary Care for Underserved Populations: Pragmatic Clinical Trials to Evaluate Real-World Comparative Effectiveness. The initiative funded this research project and one other.

Final Research Report

View this project's final research report.

Journal Citations

Article Highlight: Reporting in the New England Journal of Medicine, this study found that an intensive healthy lifestyle intervention—which included health coaches embedded in primary care practices working with patients to develop healthy habits—resulted in patients losing significantly more weight than those who received usual care from their primary care clinics, and they kept more weight off at two years later. The results show that successful weight loss can be achieved in primary care settings in a highly underserved population who have significant barriers to obtaining health care services.

Peer-Review Summary

Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.

The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments. 

Peer reviewers commented and the researchers made changes or provided responses. Those comments and responses included the following:

  • The reviewers requested more information about how the health coaches who provided intensive lifestyle interventions fit into the clinical practices where they worked, including information about their access to medical records and their reimbursement for services. The researchers explained that the coaches were all salaried employees paid by the PCORI award and did not bill for their services. The coaches did not have access to electronic medical records and did not communicate with providers about patients because of privacy concerns. Similarly, primary care providers knew that their patients were participating in this study but did not have access to the computer tracking system used in the research.
  • The reviewers asked how often participants used the computerized tool for tracking weight and feedback from coaches. The researchers explained that while the computer tracking system was designed for participants, participant use of the system was not systematically assessed. The researchers estimated that most participants did not access the computer tracking system’s weight graphs on their own but instead viewed printed versions of graphs that their health coaches provided.
  • The reviewers requested that the researchers discuss the clinical significance of functional status measures, rather than reporting only statistical significance. The researchers noted that determining the clinical significance on quality of life and functioning measures was dependent on the population. Therefore, they revised the report noting whether or not the differences between treatment groups fell into the range where they would  be considered clinically significant, but also cautioned readers that the range for clinical significance was not established in a population similar to this study’s.
  • The reviewers asked why weight loss in the intensive lifestyle intervention group appeared to be less among African Americans and how weight loss could be increased in that population. The researchers said this is an important question that the study had not explored. They added that they will address the issue of lower weight loss among African American populations in a future paper.

Conflict of Interest Disclosures

Project Information

Peter T. Katzmarzyk, PhD
Pennington Biomedical Research Center
The Louisiana Trial to Reduce Obesity in Primary Care

Key Dates

September 2014
December 2020

Study Registration Information


Has Results
Award Type
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: January 20, 2023