Effect of an Intervention Program of Adapted Physical Activity Combined With Compensatory Nutrition in Patients With Constitutional Thinness (ANIMATION)

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 Overview

• Status: Recruiting
• Conditions: Constitutional Thinness
• Intervention / Treatment: Other: Adapted Physical Activity (APA); Behavioral: Compensatory Nutrition (NC)

• Study Type: Interventional
• Enrollment (Estimated): 62
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Natacha GERMAIN, PhD; Phone Number: +33 (0)477120621; Email: natacha.germain@chu-st-etienne.fr
• Study Contact Backup: Name: Florence RANCON, Cheffe de projet; Phone Number: +33 (0) 477829458; Email: florence.rancon@chu-st-etienne.fr

Study Locations

• France
  • France
    • Saint-Etienne, France, France, 42055
      • Recruiting
      • CHU de Saint-Etienne
      • Sub-Investigator: Léonard FEASSON, PhD
      • Contact: Natacha GERMAIN, PhD; Phone Number: +33 (0)477120621; Email: natacha.germain@chu-st-etienne.fr
      • Contact: Florence RANCON, Cheffe de projet; Phone Number: +33 (0) 477829458; Email: florence.rancon@chu-st-etienne.fr
      • Sub-Investigator: Bogdan GALUSCA, PhD
      • Sub-Investigator: David HUPIN, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• 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

Exclusion Criteria:

• 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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: APA + NC	Other: 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.; Behavioral: 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.
No Intervention: Control; 2-week run-in period; Followed by an 8-week period of conventional management without APA and without NC

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Lean body mass	Lean body mass gain (kg) measured by bioimpedance	From day 1 to week 8

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
BMI	Body masse index : ratio between weight and height	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);	From day 1 to week 8
Physical exercise capacity	Changes in VO2max	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);	From day 1 to week 8

Collaborators and Investigators

• Sponsor: Centre Hospitalier Universitaire de Saint Etienne
• Collaborators: Laboratoire Interuniversitaire de Biologie de la Motricité; Target Tape

Study record dates

Study Major Dates

• Study Start (Actual): July 7, 2025
• Primary Completion (Estimated): March 1, 2026
• Study Completion (Estimated): June 1, 2026

Study Registration Dates

• First Submitted: February 4, 2025
• First Submitted That Met QC Criteria: March 18, 2025
• First Posted (Actual): March 25, 2025

Study Record Updates

• Last Update Posted (Estimated): October 7, 2025
• Last Update Submitted That Met QC Criteria: October 2, 2025
• Last Verified: October 1, 2025

More Information

Terms related to this study

• Keywords: Adapted Physical Activity; Constitutional thinness (CT); Compensatory nutrition; Lean and muscle mass gain; Resistance to gain weight
• Additional Relevant MeSH Terms: Body Weight; Thinness
• Other Study ID Numbers: 24CH263; ANSM (Other Identifier: 2025-A01697-42)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No