NCT06894043

Brief Summary

Constitutional Thinness (CT) is a form of stable thinness without malnutrition but with resistance to weight gain, affecting approximately 1% of the general population. The clinical consequences are numerous and the pathophysiology remains poorly understood. Currently, conventional management involves a high-calorie and frequent diet, combined with the avoidance of endurance physical activity, although there is no significant evidence of its effectiveness. Our hypothesis is that an adapted physical activity program (APA) combined with compensatory nutrition (CN) could help these patients gain lean mass (muscle mass).

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
62

participants targeted

Target at P50-P75 for not_applicable

Timeline
1mo left

Started Jul 2025

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

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Study Timeline

Key milestones and dates

Study Progress93%
Jul 2025Jun 2026

First Submitted

Initial submission to the registry

February 4, 2025

Completed
2 months until next milestone

First Posted

Study publicly available on registry

March 25, 2025

Completed
3 months until next milestone

Study Start

First participant enrolled

July 7, 2025

Completed
8 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

March 1, 2026

Completed
3 months until next milestone

Study Completion

Last participant's last visit for all outcomes

June 1, 2026

Expected
Last Updated

October 7, 2025

Status Verified

October 1, 2025

Enrollment Period

8 months

First QC Date

February 4, 2025

Last Update Submit

October 2, 2025

Conditions

Constitutional Thinness

Keywords

Constitutional thinness (CT)Adapted Physical ActivityCompensatory nutritionLean and muscle mass gainResistance to gain weight

Outcome Measures

Primary Outcomes (1)

  • Lean body mass

    Lean body mass gain (kg) measured by bioimpedance

    From day 1 to week 8

Secondary Outcomes (4)

  • BMI

    From day 1 to week 8

  • Energy balance

    From day 1 to week 8

  • Physical exercise capacity

    From day 1 to week 8

  • Quality of life SF-12 questionnaire

    From day 1 to week 8

Study Arms (2)

APA + NC

EXPERIMENTAL
Other: Adapted Physical Activity (APA)Behavioral: Compensatory Nutrition (NC)

Control

NO INTERVENTION

* 2-week run-in period * Followed by an 8-week period of conventional management without APA and without NC

Interventions

Adapted Physical Activity (APA)OTHER

The APA intervention will consist of a 2-week running-in period, followed by a period of adapted physical activity (APA) for 8 weeks.

APA + NC
Compensatory Nutrition (NC)BEHAVIORAL

The Compensatory Nutrition (NC) intervention will consist of a 2-week running-in period, followed by a period of compensated nutrition (NC) for 8 weeks.

APA + NC

Eligibility Criteria

Age18 Years - 50 Years
Sexfemale
Healthy VolunteersNo
Age GroupsAdult (18-64)

You may qualify if:

  • Gender: Female
  • BMI: ≤ 18.5 kg/m²
  • Weight Stability: Stable weight for at least 3 months
  • Diagnosed with Constitutional thinness

You may not qualify if:

  • Pregnancy, Parturition, or Lactation
  • Legal Restrictions: Individuals deprived of liberty, involuntarily hospitalized, or hospitalized for reasons other than research purposes, adults under legal protection (guardianship or curatorship) or unable to provide consent
  • Eating Disorders: Individuals with eating disorders (DSM IV and 5 criteria)
  • Excessive Alcohol Consumption: Consumption exceeding the equivalent of 10 glasses of wine per week
  • Severe Progressive Conditions: Progressive severe conditions (e.g., diabetes)
  • Intense Physical Activity: Individuals engaging in intense physical activity (\> 3 sessions per week)
  • Heavy Smoking: Significant smoking (\>10 cigarettes per day)
  • Psychiatric Conditions: Presence of depressive or psychiatric conditions requiring antidepressant or psychotropic treatment
  • Medical or Surgical History: Medical or surgical history deemed incompatible with the study by the investigator
  • MRI Contraindication: Individuals with contraindications to MRI will not undergo spectro-MRI analyses

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

CHU de Saint-Etienne

Saint-Etienne, France, 42055, France

RECRUITING

Central Study Contacts

Natacha GERMAIN, PhD

CONTACT

(0)477120621natacha.germain@chu-st-etienne.fr

Florence RANCON, Cheffe de projet

CONTACT

(0) 477829458florence.rancon@chu-st-etienne.fr

Study Design

Study Type
interventional
Phase
not applicable
Allocation
RANDOMIZED
Masking
NONE
Purpose
TREATMENT
Intervention Model
PARALLEL
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

February 4, 2025

First Posted

March 25, 2025

Study Start

July 7, 2025

Primary Completion

March 1, 2026

Study Completion (Estimated)

June 1, 2026

Last Updated

October 7, 2025

Record last verified: 2025-10

Locations

FR(1)