Redefining Evaluation of Adiposity and Leanness: Broadening Objective Diagnostics for Obesity (REAL-BODY)

August 17, 2026 updated by: Foundation for the National Institutes of Health

Redefining Evaluation of Adiposity and Leanness: Broadening Objective Diagnostics for Obesity (REAL-BODY)

The purpose of this study is to evaluate body composition across a variety of medical, professional, and commercial devices, including: bioelectrical impedance analysis (BIA) devices, 3-dimensional optical imaging (3DO), manual anthropometry measurements, dual-energy X-ray absorptiometry (DXA), magnetic resonance imaging (MRI), and blood tests. The secondary study purpose is to compare body composition measurements from BIA devices, 3DO, and manual anthropometry measurements within a 1-week period for a subset of the study population.

The study plans to enroll 300 healthy (having no life-threatening conditions or diseases; male and female) participants, 18 years of age or older.

Study Overview

Status

Recruiting

Conditions

Detailed Description

Obesity is a disease of excess and abnormal distribution of adipose tissue. Even though negative metabolic outcomes of obesity are driven by adipose tissue, investigators still use body weight (comprised of both fat and fat-free mass) in the calculation of body mass index (weight in kg divided by height in meters squared) to define, subclassify and monitor treatment in people with obesity. Despite this traditional focus on body weight, body composition is an important consideration in the management of people with obesity.

Clinical trials and clinical research often use DXA and MRI to quantify changes in body composition; however these methods are expensive and not easily implemented. It is desirable to monitor fat mass and other body composition outcomes in individuals with obesity taking weight loss medications as well as when new weight management therapeutic drugs are developed.

Most weight loss medications are associated with loss of both fat mass and fat-free mass with the "quality of weight loss" defined as the proportion of weight lost as fat mass, equal to 60-75%. Recognizing that loss of fat-free mass during weight loss is undesirable, several companies are developing lean mass preserving weight loss agents. For these agents, stepping on a weight scale will no longer be an accurate measure of benefit; loss in fat is offset by gains in lean, rendering body weight changes as an inaccurate measure of weight loss quality. Therefore, the application of body composition measurements will be required for patients, physicians, and payors to monitor treatment in people with obesity. In order for this to occur, investigators need scalable body composition measurements for fat mass.

Bioelectrical impedance analysis (BIA) offers a more scalable approach as the time, cost and footprint of BIA devices make them appropriate for a physician's office and for clinical research trials. Traditionally, BIA devices have been deemed to possess insufficient accuracy for body composition quantification. While this decreased accuracy was an obstacle for first generation weight loss medications with less weight loss, it is possible that with the newer generation of weight loss medications that confer greater weight loss, BIA may be adequate to measure changes in body composition occurring over time in individuals losing weight. Additionally, notable technological innovation has occurred in the field of bioimpedance, with several new devices possessing improved hardware and software as compared to previously evaluated analyzers. As such, these devices are expected to outperform traditional BIA systems.

Other accessible technologies that are practical to apply in clinical research and practice have appeared in recent publications. These include three-dimensional optical systems (3DO) housed in smartphones and multi-omics blood tests capable of estimating various body compartments. To the extent that BIA and these newer technologies can serve as useful sufficiently reproducible phenotypic measures of a person's body composition remains largely unknown. In addition to the dichotomy of fat mass vs fat-free mass, not all fat mass is created equal. Superficial or subcutaneous fat mass is thought to be metabolically healthy whereas visceral central fat is thought to be metabolically unhealthy. Furthermore, visceral fat is associated with long-term morbidity and mortality. Therefore, another dimension of body composition is the proportion of fat in the visceral vs subcutaneous compartments.

Currently, MRI is the gold standard method to measure visceral fat. Some BIA analyzers provide estimations of visceral fat, and digital anthropometry derived from 3D scanning can also be used in visceral fat estimation equations. As such, an additional goal of this project is to determine if visceral fat can be accurately estimated in the real-world using BIA or 3DO. Currently there are two major manufacturers of DXA devices, Hologic and General Electric (GE). Accuracy and precision data for body composition measures using DXA have been published. For BIA, there are several different manufacturers including InBody, Tanita, Seca, and Impedimed. Likewise, several companies produce 3DO smartphone systems, and one company provides multi omics blood evaluations for body composition. It is not known which of these devices and measurement platforms (if any) have adequate accuracy to measure body composition. The overall goal of this project is to bring measurement of body composition to the real world to improve the diagnosis, classification, and monitoring of treatment in people with obesity, both in clinical research trials and medical practice. Adipose or fat mass needs to become a new "vital sign." This project could have a large impact on the treatment of people with obesity. Accurate implementation of body composition analysis in the real world could lead to the development of treatment goals for obesity based on either total fat mass and/or visceral fat mass.

Study Type

Observational

Enrollment (Estimated)

300

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • United States
    • Arizona
      • Phoenix, Arizona, United States, 85027
    • California
      • Menlo Park, California, United States, 94025
        • Not yet recruiting
        • Exponent Menlo Park
    • Massachusetts
      • Boston, Massachusetts, United States, 01760

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

N/A

Sampling Method

Non-Probability Sample

Study Population

A diverse sample of adults will be recruited for participation in the US. Stratification will occur based on sex and BMI, with additional targets to promote recruitment of a variety of ages and adequate representation of racial and ethnic categories. For race and ethnicity, the goal will be to obtain a distribution approximately equal to the demographics of the United States, with selective oversampling employed as needed. For BMI, the following percentages will be used as approximate goals for the sample (18.50-19.99, None; 20.00-24.99, 20%; 25.00-29.99, 35%; 30.00-34.99, 25%; 35.00-39.99, 13.30%; 40.00-44.99, 6.70%; ≥45, None). However, the distribution of BMI and other demographic characteristics will be monitored as the study progresses in case adjustment is needed.

Description

Inclusion Criteria:

  • Being willing to provide written informed consent prior to participation Being willing to complete the study visits and comply with the study procedures
  • Being willing to travel to the various study locations for On-site, DXA, MRI, and Phlebotomy visits
  • Being willing to change into appropriate form-fitting clothing for 3DO assessments and/or appropriate gowns for DXA and MRI imaging
  • Must have a BMI within the range of 18.5 - 45 kg/m2
  • Being willing to refrain from all food, drink, and substances for 8 hours prior to the On-site visit(s) and phlebotomy visit
  • Being willing to refrain from all food, drink, and substances for 4 hours prior to the DXA and MRI scan visits
  • Being willing to refrain from any exercise or vigorous physical activity for 24 hours prior to all visits
  • Stable weight (no more than 5 kg change) for 3 months prior to screening
  • If recruited in the Phoenix, AZ area, participants must be willing to drive yourself to the Phoenix Office location for the On-site Visits 1 and 2 (if applicable) located at the Exponent Phoenix Office.

Exclusion Criteria:

  • Being pregnant or attempting to become pregnant
  • Having medical implants, such as a pacemaker or metal joint replacements, or other metal implants contraindicated for MRI
  • Cosmetic implants, such as breast implants
  • Having a height greater than DXA scanning limit (77 inches)
  • Having a body weight greater than indicated for the equipment (400 lbs)
  • Prior amputation or major body-altering surgery that could invalidate body composition estimates
  • Having claustrophobia or a history of claustrophobia
  • Known HIV infection
  • Known Lipodystrophy
  • Known hydration abnormality (e.g., significant edema, end-stage renal disease, end-stage liver disease)
  • Severe illness or life-threatening conditions such as end-stage kidney, liver, lung disease, NYHA III-IV heart failure, or active malignancy

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Modality-reference agreement for total fat mass (kg)
Time Frame: 4 Weeks
Agreement between bioimpedance and 3-dimensional optical imaging derived estimates of total fat mass and DXA-derived reference measurements.
4 Weeks
Modality-reference agreement for fat-free mass (kg)
Time Frame: 4 Weeks
Agreement between bioimpedance and 3-dimensional optical imaging derived estimates of fat-free mass and DXA-derived reference measurements.
4 Weeks
Modality-reference agreement for percent body fat (%)
Time Frame: 4 Weeks
Agreement between bioimpedance and 3-dimensional optical imaging derived estimates of percent body fat and DXA-derived reference measurements.
4 Weeks
Modality-reference agreement for visceral adipose tissue (VAT; kg or volume)
Time Frame: 4 Weeks
Agreement between bioimpedance and 3-dimensional optical imaging derived estimates of visceral adipose tissue and MRI-derived reference measurements.
4 Weeks

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Agreement of blood-based proteomics-derived fat-free mass with DXA-derived fat-free mass (kg)
Time Frame: 4 Weeks
Agreement between blood-based proteomics-derived fat-free mass and DXA-derived fat-free mass, assessed using the prespecified agreement analyses.
4 Weeks
Agreement of blood-based proteomics-derived total fat mass with DXA-derived total fat mass (kg)
Time Frame: 4 Weeks
Description: Agreement between blood-based proteomics-derived total fat mass and DXA-derived total fat mass, assessed using the prespecified agreement analyses.
4 Weeks
Agreement of blood-based proteomics-derived percent body fat with DXA-derived percent body fat (%)
Time Frame: 4 Weeks
Agreement between blood-based proteomics-derived percent body fat and DXA-derived percent body fat, assessed using the prespecified agreement analyses.
4 Weeks
Agreement of blood-based proteomics-derived visceral adipose tissue with MRI-derived visceral adipose tissue
Time Frame: 4 Weeks
Agreement between blood-based proteomics-derived visceral adipose tissue and MRI-derived visceral adipose tissue, assessed using the prespecified agreement analyses
4 Weeks
Obesity and elevated visceral adipose tissue classification
Time Frame: 4 Weeks
Classification performance of bioimpedance (BIA), 3-dimenisonal optics imaging (3DO), and blood-based methods for obesity and elevated visceral adipose tissue (VAT) status, assessed using area under the receiver operating characteristic curve (AUC) based on prespecified thresholds.
4 Weeks
Regression-based assessment of demographic and anthropometric effects on modality-reference measurement error
Time Frame: 4 Weeks
Regression models will be used to evaluate the effects of prespecified demographic and anthropometric covariates, including age, sex, and BMI, on measurement error between candidate body composition methods and the corresponding DXA or MRI reference method.
4 Weeks
Between-day reliability of BIA measurements assessed by intraclass correlation coefficient (ICC)
Time Frame: 1 Week
Intraclass correlation coefficients with 95% confidence intervals will be calculated for repeated BIA measurements obtained during the protocol-specified repeat-visit window of 2-7 days.
1 Week
Between-day reliability of 3DO measurements assessed by intraclass correlation coefficient (ICC)
Time Frame: 1 Week
Intraclass correlation coefficients with 95% confidence intervals will be calculated for repeated 3DO measurements obtained during the protocol-specified visit window of 2-7 days.
1 Week
Between-day reliability of BIA measurements assessed by technical error of measurement (TEM)
Time Frame: 1 Week
Technical error of measurement will be calculated for repeated BIA measurements obtained during the protocol-specified repeat-visit window of 2-7 days.
1 Week
Between-day reliability of 3DO measurements assessed by technical error of measurement (TEM)
Time Frame: 1 Week
Technical error of measurement will be calculated for repeated 3DO measurements obtained during the protocol-specified repeat-visit window of 2-7 days
1 Week
Exploratory predictive performance of novel 3DO-derived geometric and anthropometric features for visceral adipose tissue
Time Frame: 4 Weeks
Exploratory models incorporating 3DO-derived geometric and anthropometric features will be evaluated for estimation of visceral adipose tissue relative to MRI-derived reference measurements using regression-based predictive performance measures.
4 Weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Foundation for the National Institutes of Health

Collaborators

Pennington Biomedical Research Center
Texas Tech University
Exponent, Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 29, 2026

Primary Completion (Estimated)

November 30, 2026

Study Completion (Estimated)

March 30, 2027

Study Registration Dates

First Submitted

July 14, 2026

First Submitted That Met QC Criteria

August 17, 2026

First Posted (Actual)

August 20, 2026

Study Record Updates

Last Update Posted (Actual)

August 20, 2026

Last Update Submitted That Met QC Criteria

August 17, 2026

Last Verified

August 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 00329050

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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