Validation of Energy Expenditure Measures Study (ValEE)

April 29, 2026 updated by: Sascha Heinitz, University of Leipzig

Energy Balance Within a Whole-Room Indirect Calorimeter and Its Relevance for Energy Expenditure Measures

The energy that the human body burns and the amount of food consumed determine a person's body weight. If food intake covers the amount of energy burned, body weight remains constant - a state known as energy balance. Achieving an energy balance is not easy in everyday life. This is reflected in the increasing number of people suffering from morbid obesity. To counteract this development, it is important to have a better understanding of how much food a person should eat.

In this study, the investigators will investigate the amount of food needed to meet a person's energy needs and bring them into energy balance.

Primary aims of the study are i) to technically and biologically validate two whole-room indirect calorimeters (WRICs) and ii) by using whole-room indirect calorimetry, to achieve a more accurate estimate of a person's emergy balance compared to common approximation formulas.

Secondary study aims:

  1. To investigate whether the transfer of a person into energy balance using WRIC has an influence on energy expenditure measures compared to the transfer into energy balance using the usual approximation formula.
  2. To investigate whether the transfer of a person into energy balance using WRIC has an influence on activity-dependent energy expenditure measures compared to the transfer into energy balance using the usual approximation formula.
  3. To investigate whether differences in energy expenditure during energy balance during moderate and strenuous physical activity influence food intake.
  4. To investigate whether energy intake in relation to energy expenditure during energy balance is related to weight development

Study Overview

Status

Recruiting

Conditions

Detailed Description

Technical Validation: Eight 24-hour methanol burns within each of the two WRICs will be conducted for technical validation.

Biological Validation and Energy Balance Component:

After providing informed consent and meeting inclusion/exclusion criteria, study participants will follow a weight-maintaining diet before their first 24-hour stay in a WRIC (Day 4). During this stay, energy expenditure will be measured under conditions of estimated energy balance. As a measure of energy expnediture relative to energy intake, energy balance will be estimated based on resting energy expenditure, an estimated physical activity level, and an approximation formula applied during the screening procedure.

A second 24-hour stay in the WRIC (Day 6), also under conditions of estimated energy balance, will serve for biological validation. After following the weight-maintaining diet for three additional days, a third 24-hour WRIC stay (Day 10) will assess the achievement of near-perfect energy balance. On the day following this stay (Day 11), participants will have access to a buffet and will be allowed to eat ad libitum.

Subsequently, a 3-day run-in period under weight-maintenance conditions will precede reassessment of 24-hour energy expenditure during increased physical activity in the WRIC (Days 15 and 17). Energy expenditure during energy balance will again be compared to ad libitum food intake at a buffet (Day 18).

Follow-up weight measurements will be conducted one year after study completion to evaluate the influence of achieving near-perfect energy balance-or deviations from it-on weight change. Additionally, fasting blood samples will be collected before and after each WRIC stay, as well as before and after ad libitum food intake, to measure hormones related to appetite control and satiety.

N = 34 subjects are required to detect a statistically significant difference in energy balance after measuring energy expenditure using a WRIC. However, interim analysis after n = 8 subjects will be conducted to adjust needed sample size to variability as detected using here implied methods of indirect calorimetry.

The statistical evaluation with regard to i) technical validation, ii) biological validation, and iii) testing the achievability of an energy balance and its effect on energy consumption are carried out using parametric and non-parametric tests. Data are given as mean value with standard deviation. The significance level is P < 0.05.

Study Type

Observational

Enrollment (Estimated)

34

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

  • Name: Haiko Schlögl, MD
  • Phone Number: +49 341 97 13389

Study Locations

  • Germany
    • Saxony
      • Leipzig, Saxony, Germany, 04103
        • Recruiting
        • Department of Internal Medicine, Clinic for Endocrinology, Nephrology and Rheumatology, University of Leipzig
        • Contact:
        • Contact:
        • Principal Investigator:
          • Sascha Heinitz, MD

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

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Healthy, non-obese subjects of both sexes.

Description

Inclusion Criteria:

  • Abilty to provide informed consent
  • Written declaration of consent
  • Healthy study participants
  • Able to perform moderate physical exercise using a bike ergometer
  • Women: continuous contraception/fullicular phase of menstrual cycle

Exclusion Criteria:

  • Weight change > 5 kg or 5% of body weight in the last 3 months
  • Nicotine abuse, Alcohol/drug abuse
  • Strenuous physical activity in everyday life > 1 h per day
  • Body mass index < 18.5 kg/m² or ≥ 40 kg/m²
  • Chronic diseases with an impact on energy expenditure
  • Food allergy/intolerance, vegan diet
  • Circumstances that speak against the application of wearable accelerometers (e.g. silicone contact allergy)
  • Impaired fasting glucose, diabetes mellitus and prediabetes
  • Pregnancy/breastfeeding
  • Claustrophobia
  • Refusal to communicate incidental findings

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

Cohorts and Interventions

Group / Cohort
Healthy
Healthy subjects of both sexes meeting inclusion criteria.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Energy expenditure
Time Frame: From enrollement to the end of 5th stay within the whole-room indirect calorimeter, study day 18.
Repeated assessment of energy expenditure in the setting of a whole-room indirect calorimeter and relative to prior energy expenditure assessment using the ventilated hood method (canopy) and estimation formula.
From enrollement to the end of 5th stay within the whole-room indirect calorimeter, study day 18.
Energy intake
Time Frame: From enrollement to the end of 5th stay within the whole-room indirect calorimeter, study day 18.
Repeated assessment of energy intake in the setting of a whole-room indirect calorimeter and relative to prior energy expenditure assessment using the ventilated hood method (canopy) and estimation formula.
From enrollement to the end of 5th stay within the whole-room indirect calorimeter, study day 18.
Coefficient of variation
Time Frame: Prior to enrollement of subjects (technical validation). From enrollement to the end of second stay within the whole-room indirect calorimeter, study day 7.
Technical and biological validation via repeated assessment of methanol combustion as well as repeated stays within the whole-room indirect calorimeters. Measures: recovery, accuracy, macronutrient oxidation rates, respiratory exchange ratio, energy expenditure measures.
Prior to enrollement of subjects (technical validation). From enrollement to the end of second stay within the whole-room indirect calorimeter, study day 7.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Energy expenditure
Time Frame: From enrollement to the end of 5th stay within the whole-room indirect calorimeter, study day 11.
Compared to common approximation formulas, achieving near perfect energy balance using a WRIC has an influence on energy expenditure measures (i.e. 24-hour energy expenditure, sleeping energy expenditure, diet-induced thermogenesis/awake-and-fed thermogenesis, physical exercise energy expenditure)
From enrollement to the end of 5th stay within the whole-room indirect calorimeter, study day 11.
Physical exercise expenditure
Time Frame: From enrollement to the end of 5th stay within the whole-room indirect calorimeter, study day 18.
Compared to common approximation formulas, achieving near perfect energy balance using a WRIC has an influence on energy expenditure measures in the setting of increased physical activity (i.e. 24-hour energy expenditure, sleeping energy expenditure, diet-induced thermogenesis/awake-and-fed thermogenesis, physical exercise energy expenditure)
From enrollement to the end of 5th stay within the whole-room indirect calorimeter, study day 18.
Concentrations of hormones involved in energy intake
Time Frame: From enrollement to the end of 5th stay within the whole-room indirect calorimeter, study day 18.
(Deviation from) near perfect energy balance relates to ad libitum energy intake and changes in hormones implied in appetite control/satiety. Outcome measures: ad libitum food intake during buffet, Leptin, Ghrelin, thyroid hormones, Cortisol, Insulin, IGF-1, Adiponectin, FGF21)
From enrollement to the end of 5th stay within the whole-room indirect calorimeter, study day 18.
Body weight change
Time Frame: From enrollement to the end of 5th stay within the whole-room indirect calorimeter, study day 18. Body weight change follow-up one year after completion of the study.
(Deviation from) near perfect energy balance relates to body weight change.
From enrollement to the end of 5th stay within the whole-room indirect calorimeter, study day 18. Body weight change follow-up one year after completion of the study.

Collaborators and Investigators

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

Sponsor

University of Leipzig

Collaborators

University of Pisa
Helmholtz Center Munich

Investigators

  • Principal Investigator: Sascha Heinitz, MD, University of Leipzig

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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)

August 26, 2025

Primary Completion (Estimated)

January 31, 2029

Study Completion (Estimated)

January 31, 2029

Study Registration Dates

First Submitted

January 20, 2025

First Submitted That Met QC Criteria

August 26, 2025

First Posted (Actual)

September 4, 2025

Study Record Updates

Last Update Posted (Actual)

April 30, 2026

Last Update Submitted That Met QC Criteria

April 29, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 121-24/ek

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

The decision not to share IPD is based on considerations of participant privacy and data protection. Although all data are anonymized, the sensitive nature of the information collected in this study necessitates careful handling to minimize any risk of identification. Furthermore, the informed consent provided by participants does not explicitly include provisions for data sharing beyond the current study.

To ensure compliance with ethical guidelines and data protection regulations, the study team has decided not to make IPD available publicly or to external researchers. However, summary data and study findings will be shared through peer-reviewed publications, ensuring transparency and the opportunity for scientific discourse.

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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