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Not yet recruitingNCT07628764Updated Jun 5, 2026

Within-Individual Variability of Resting Metabolic Rate Over 12 Weeks

An observational study in Resting Metabolic Rate and Energy Metabolism, sponsored by Tel Aviv University. Not yet recruiting. Open to participants aged 18 Years to 65 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-06-05.

Sponsored by Tel Aviv University · Observational

Study type
Observational
Model
Other
Time perspective
Prospective
Enrollment
30
Ages
18 Years to 65 Years
Sex
All
01

Study summary

This prospective observational study aims to characterize within-individual variability in resting metabolic rate (RMR) over a 12-week period using high-frequency repeated measurements under standardized conditions. Participants will undergo RMR assessments three times per week using whole-room indirect calorimetry.

The study will quantify the magnitude of physiological variability in RMR, distinguish true biological variation from measurement error, and estimate the minimal detectable change required to identify meaningful metabolic adaptations.

Read the detailed description

Resting metabolic rate (RMR) is a major component of total daily energy expenditure and is widely used in metabolic research. However, most studies rely on single or infrequent measurements, assuming RMR is stable within individuals.

Emerging evidence suggests that RMR exhibits measurable within-individual variability, but the temporal structure and magnitude of this variability remain poorly characterized.

This study will implement a high-frequency repeated-measures design, with RMR measured three times per week over 12 weeks using whole-room indirect calorimetry under standardized conditions. This approach will allow detailed characterization of short-term variability and provide estimates for within-subject variability, measurement error, and minimal detectable change.

The findings will inform interpretation of longitudinal metabolic studies and improve study design in future research.

02

Conditions studied

  • Resting Metabolic Rate
  • Energy Metabolism

Keywords

  • Resting Metabolic Rate
  • Energy Expenditure
  • Metabolism
  • Indirect Calorimetry
  • Variability
03

Who can participate

Ages eligible
18 Years to 65 Years
Sexes eligible
All
Accepts healthy volunteers
Yes
Sampling method
Non-probability sample

Study population

Healthy adult men and women from the community, aged 18-65 years, who are clinically healthy and able to participate in repeated metabolic measurements under standardized laboratory conditions.

Inclusion criteria

  • Adults aged 18-65 years
  • Clinically healthy individuals
  • Stable body weight (±2 kg) over the past 3 months
  • Ability and willingness to attend morning measurements three times per week for 12 weeks
  • Ability to provide informed consent

Exclusion criteria

Exclusion Criteria:

  • Known uncontrolled endocrine or metabolic disease
  • Use of medications known to significantly affect resting metabolic rate (e.g., systemic corticosteroids, unstable thyroid hormone therapy)
  • Acute illness within 14 days prior to enrollment
  • Pregnancy or lactation
  • Any medical condition that, in the opinion of the investigators, may interfere with safe participation
04

Study design

Observational model
Other
Time perspective
Prospective
Enrollment
30 participants (estimated)
Patient registry
No

Groups and cohorts

  • Healthy Adults

    Healthy adult participants undergoing repeated measurements of resting metabolic rate (RMR) three times per week over a 12-week period under standardized conditions. No intervention is applied.

    Other: Repeated Measurement of Resting Metabolic Rate

Interventions

  • OtherRepeated Measurement of Resting Metabolic Rate

    Repeated assessment of resting metabolic rate under standardized conditions; no intervention is administered.

05

What researchers measure

Primary outcomes

  1. Within-Individual Variability in Resting Metabolic Rate (RMR)

    Within-individual variability in resting metabolic rate (RMR) assessed using repeated measurements under standardized conditions. Variability will be quantified using mean, standard deviation (SD), and coefficient of variation (CV%) across repeated measurements.

    Time frame: 12 weeks

Secondary outcomes

  1. Minimal Detectable Change (MDC) in RMR

    The minimal detectable change in resting metabolic rate required to distinguish true physiological change from measurement variability.

    Time frame: 12 weeks

  2. Between-Individual Variability in RMR

    Assessment of variability in resting metabolic rate between participants based on repeated measurements.

    Time frame: 12 weeks

  3. Temporal Trends in RMR

    Assessment of systematic changes in resting metabolic rate over time using repeated measurements across the study period.

    Time frame: 12 weeks

06

Study locations

No study locations are listed for this record.

07

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

08

Registry details

Key details

Study ID
NCT07628764
Lead sponsor
Tel Aviv University
Responsible party
Gepner Yftach (Principal Investigator - Professor, Tel Aviv University) — Principal investigator
First posted
Jun 5, 2026
Start date
Jul 2026 (estimated)
Primary completion
Dec 2027 (estimated)
Completion
Dec 2027 (estimated)
Last update
Jun 5, 2026

Study contacts

Yftach Prof. Gepner
Contact
gepner@tauex.tau.ac.il
+972 50-682-8501
Lien Bruck
Contact
+972 587487431
Yftach Prof. Gepner
principal investigator · Tel Aviv University

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is not yet recruiting, as verified in Jun 2026. You cannot join it, but the record below documents what was studied.

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