Constitutional ThinnessANIMATIONNCT06894043
Effect of an Intervention Program of Adapted Physical Activity Combined With Compensatory Nutrition in Patients With Constitutional Thinness
A study testing Adapted Physical Activity (APA) and Compensatory Nutrition (NC) in people with Constitutional Thinness, run by Centre Hospitalier Universitaire de Saint Etienne at 1 site in France.
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 50 years, women only
- Conditions the study is for
- Constitutional Thinness
- What is being tested?
- Adapted Physical Activity (APA) and Compensatory Nutrition (NC)
- Type of treatment
- Lifestyle or therapy programme
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 62 participants
- Where
- 1 siteFrance
- Study dates
- 7 Jul 2025to Dec 2026
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 50 years
- Women only
- No healthy volunteers
- Adult
Who may be able to join
- Gender: Female
- BMI: ≤ 18.5 kg/m²
- Weight Stability: Stable weight for at least 3 months
- Age: 18 to 50 years old at the inclusion visit
- Diagnosed with Constitutional thinness
Who cannot join
- 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)
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- 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
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
France1 site, 1 recruiting
- Recruiting
CHU de Saint-Etienne
Saint-Etienne, France, 42055
Natacha GERMAIN, PhD, (0)477120621 ext. +33, natacha.germain@chu-st-etienne.fr
Florence RANCON, Cheffe de projet, (0) 477829458 ext. +33, florence.rancon@chu-st-etienne.fr
About this study
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).
- Conditions
- Constitutional Thinness
- Being tested
- Adapted Physical Activity (APA), Compensatory Nutrition (NC)
- Keywords
- Constitutional thinness (CT), Adapted Physical Activity, Compensatory nutrition, Lean and muscle mass gain, Resistance to gain weight
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
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.
Compensatory Nutrition (NC)Behavioural
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.
| Study group | Role | What they receive |
|---|---|---|
| APA + NC | Experimental | Not described Receives: 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 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Lean body mass
Lean body mass gain (kg) measured by bioimpedance
Measured: From day 1 to week 8
Secondary outcomes (4)
BMI
Body masse index : ratio between weight and height
Measured: From day 1 to week 8
Energy balance
Ratio between calorie intake and calorie expenditure
Caloric intake measured by dietary records over 2 weeks (calorie); Calorie expenditure: Resting metabolism measured by indirect calorimetry (kcal/24h); + Postprandial thermogenesis measured by indirect calorimetry (kcal/24h);; + Physical activity energy expenditure measured by connected watch (kcal/24h);
Measured: From day 1 to week 8
Physical exercise capacity
Changes in VO2max
Measured: From day 1 to week 8
Quality of life SF-12 questionnaire
SF-12 questionnaire; Self-measurement questionnaire SF-12 (Short Form Health Survey 12); comprising 12 questions assessing 8 dimensions, namely physical functioning, role limitation due to physical problems, role limitation resulting from emotional problems, vitality (energy/fatigue), emotional well-being, social functioning, bodily pain, and perception of general and mental health; each dimension is represented by a score ranging from 0 to 100, with a low score signifying poor health perception in the dimension considered, and a high score signifying the opposite);
Measured: From day 1 to week 8
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Mar 2025
- Study start7 Jul 2025
- Primary completionOct 2026 (estimated)
- Study completionDec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Constitutional ThinnessStudies of the same condition, open and under way.
- More trials run by Centre Hospitalier Universitaire de Saint EtienneThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 62 participants (estimated)
Sponsor and investigators
- Sponsor type
- University, hospital or other
- Collaborators
- Laboratoire Interuniversitaire de Biologie de la Motricité, Target Tape
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06894043
- Sponsor's protocol ID
- 24CH263
- Other IDs
- ANSM
- Acronym
- ANIMATION
- Status last verified
- Sep 2026
- First submitted
- 4 Feb 2025
- Last updated
- 2 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 2 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of an Intervention Program of Adapted Physical Activity Combined With Compensatory Nutrition in Patients With Constitutional Thinness
- ClinicalTrials.gov ID
- NCT06894043
- Acronym / sponsor ID
- ANIMATION / 24CH263
- Conditions
- Constitutional Thinness
- Keywords
- Constitutional thinness (CT), Adapted Physical Activity, Compensatory nutrition, Lean and muscle mass gain, Resistance to gain weight
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 62 participants (estimated)
- Lead sponsor
- Centre Hospitalier Universitaire de Saint EtienneUniversity, hospital or other
- Collaborators
- Laboratoire Interuniversitaire de Biologie de la Motricité, Target Tape
- Study start
- 7 Jul 2025 (actual)
- Primary completion
- Oct 2026 (estimated)
- Study completion
- Dec 2026 (estimated)
- First posted
- 25 Mar 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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).
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| 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 |
Who may qualify
- Ages
- 18 to 50 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (5 listed)
- Gender: Female
- BMI: ≤ 18.5 kg/m²
- Weight Stability: Stable weight for at least 3 months
- Age: 18 to 50 years old at the inclusion visit
- Diagnosed with Constitutional thinness
Key exclusion criteria (10 listed)
- 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)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Adapted Physical Activity (APA)The APA intervention will consist of a 2-week running-in period, followed by a period of adapted physical activity (APA) for 8 weeks. | Other | APA + NC |
| Compensatory Nutrition (NC)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. | Behavioural | APA + NC |
Primary outcome
Lean body mass
Time frame: From day 1 to week 8
Lean body mass gain (kg) measured by bioimpedance
4 secondary outcomes
BMI
Time frame: From day 1 to week 8
Energy balance
Time frame: From day 1 to week 8
Physical exercise capacity
Time frame: From day 1 to week 8
Quality of life SF-12 questionnaire
Time frame: From day 1 to week 8
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 2 Oct 2026.
Related trials for Constitutional Thinness
Not yet recruiting
Energy Expenditure and Neuromuscular Function in Young Adult Women With a Naturally Thin Build (LeanErgy)
Constitutional Thinness
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Adapted Physical Activity (APA) and Compensatory Nutrition (NC) in people with Constitutional Thinness, run by Centre Hospitalier Universitaire de Saint Etienne at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 2 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Natacha GERMAIN, PhD ((0)477120621 ext. +33, natacha.germain@chu-st-etienne.fr), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Lean body mass (time frame: From day 1 to week 8). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Oct 2026.