OBESIAL: A Prospective Interventional Real-world Study of a Multidisciplinary Obesity Management Programme (OBESIAL)

The OBESIAL (Obesity Structured Intervention in Algeria) study aims to evaluate the clinical, metabolic, and organisational impact of a structured multidisciplinary obesity care pathway implemented under real-world conditions.

Study Overview

• Status: Recruiting
• Conditions: Obesity Adult Onset; Obesity and Cardiovascular Risk; Obesity Type 2 Diabetes Mellitus; Obesity Difficult Airway Airway Management
• Intervention / Treatment: Drug: Semaglutide (Wegovy) weekly injection; Behavioral: Behavioral Treatment; Other: Weight loss

Detailed Description

OBESIAL is a prospective pragmatic study involving 300 adults with obesity recruited from healthcare facilities in Algeria and followed for 18 months. The primary comparison evaluates outcomes between participants receiving structured multidisciplinary care (G1, n=150) and those receiving non-structured usual care (G2, n=150). The structured pathway includes coordinated medical follow-up, personalised nutritional intervention, adapted physical activity, therapeutic education, and multidisciplinary support.

Within the structured care group, eligible participants will undergo a nested randomised comparison between G1a (lifestyle intervention plus GLP-1 receptor agonist therapy) and G1b (lifestyle intervention alone) to assess the additional effect of GLP-1 receptor agonist treatment.

The primary outcome is the proportion of participants achieving clinically meaningful weight loss (≥5% of initial body weight) at 18 months. Secondary outcomes include changes in body composition, metabolic parameters, treatment response, adherence, and obesity-related outcomes. Longitudinal analyses will be performed using mixed-effects models, while multivariable approaches will explore factors associated with treatment response.

The findings of the OBESIAL study are expected to provide evidence to support the development and optimisation of structured multidisciplinary obesity care pathways in Algeria and may offer relevant insights for other African healthcare systems.

• Study Type: Interventional
• Enrollment (Estimated): 300
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Mounira Professor Chanegriha. Head of Medicine department, Professor; Phone Number: 3012 +21321905656; Email: m.chanegriha@univ-alger.dz

Study Locations

• Algeria
  • Algiers, Algeria, 16000
    • Recruiting
    • Department of Medicine, , Mother and Child Hospital of the Army (MCHA), Algiers University Hospital, Algiers, Algeria.

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Adults aged 18-65 years
• BMI ≥30 kg/m²
• Written informed consent obtained prior to enrolment

Exclusion Criteria:

• Refusal to participate or inability to adhere to follow-up procedures
• Pregnancy at enrolment

• Severe or unstable comorbidities compromising safety or participation, including:

  • Recent acute cardiovascular event (<60 days)
  • Active malignancy
  • Severe unstable organic disease
• Previous bariatric surgery
• Obesity pharmacotherapy within the previous 90 days
• Known contraindication to planned therapeutic options
• Severe unstable psychiatric disorders
• Genetic obesity or obesity secondary to uncontrolled endocrine disease

Exclusion Criteria During Follow-up

• Pregnancy occurring during follow-up
• Initiation of chronic treatment associated with weight gain

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

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: G1a: Structured Obesity Care + Semaglutide; Participants assigned to G1 will initially receive the structured obesity care pathway (OBESIAL) for 18 months. This structured multidisciplinary care includes coordinated medical follow-up, individualized nutritional management adapted to the sociocultural context, a personalized physical activity program, and psychological support according to individual needs. At month 6, the clinical course is reviewed during a multidisciplinary meeting. Bariatric surgery constitutes a therapeutic pathway within the structured care group and not a separate study arm based on clinical indication and patient's wishes. Among participants remaining eligible for pharmacological intervention, an embedded, independent and centralized 1:1 randomization is performed to assign participants to G1a or G1b. The semaglutide intervention is therefore an adjunct to, and not a replacement for, the structured nutritional, physical activity and behavioural interventions provided within the OBESIAL care pathway.	Drug: Semaglutide (Wegovy) weekly injection; Semaglutide (Wegovy®) will be administered as a subcutaneous injection once weekly, with gradual dose escalation according to the recommended dosing schedule for the molecule, up to a target maintenance dose of 2.4 mg once weekly, for 12 months. Semaglutide will be initiated as an adjunct to the structured OBESIAL obesity care pathway in eligible participants randomized to G1a, following a second written informed consent specifically for the pharmacological intervention.; Behavioral: Behavioral Treatment; Structured care group (G1): Only participants in G1 will undergo the structured care pathway over 18 months.; Individualised nutritional follow-up adapted to the sociocultural context, consisting of eight sessions, including nutritional education sessions lasting 30 minutes and evaluation sessions lasting 15 minutes.; An individually tailored physical activity programme based on baseline functional capacity and associated comorbidities. Participants will be encouraged to attend supervised or structured physical activity sessions three times per week, with adjustments according to tolerance and clinical status.; Psychological support provided according to individual needs, focusing on motivation, emotional eating, barriers to adherence, and behavioural change strategies. The frequency of psychological follow-up will be adapted to patient requirements, reflecting the pragmatic nature of the intervention.; Other Names: Structured Care Pathway
Active Comparator: G1b : Structured care group / lifestyle intervention alone; Participants assigned to G1 initially receive the structured obesity care pathway (OBESIAL) for 18 months, including coordinated medical follow-up, individualized nutritional management adapted to the sociocultural context, a personalized physical activity program, and psychological support according to individual needs. The structured multidisciplinary assessment involves general practitioners, endocrinologists-diabetologists, dietitians, psychologists and psychiatrists, with referral to organ specialists according to obesity-related comorbidities, including cardiology, pulmonology, gastroenterology, rheumatology and stomatology. Adapted physical activity interventions are supervised by sports medicine physicians or physiotherapists, with functional capacity assessment performed by rehabilitation specialists. Participants randomized to G1b continue the structured obesity care pathway without initiation of pharmacological treatment with semaglutide as part of the study intervention.	Behavioral: Behavioral Treatment; Structured care group (G1): Only participants in G1 will undergo the structured care pathway over 18 months.; Individualised nutritional follow-up adapted to the sociocultural context, consisting of eight sessions, including nutritional education sessions lasting 30 minutes and evaluation sessions lasting 15 minutes.; An individually tailored physical activity programme based on baseline functional capacity and associated comorbidities. Participants will be encouraged to attend supervised or structured physical activity sessions three times per week, with adjustments according to tolerance and clinical status.; Psychological support provided according to individual needs, focusing on motivation, emotional eating, barriers to adherence, and behavioural change strategies. The frequency of psychological follow-up will be adapted to patient requirements, reflecting the pragmatic nature of the intervention.; Other Names: Structured Care Pathway
Active Comparator: G2: Non-structured care group; Participants in G2 receive usual, non-structured obesity care delivered independently of the OBESIAL structured care pathway and outside the study coordinating structure. Care is provided in comparable healthcare structures in order to reflect usual clinical practice while limiting differences related to the type or level of healthcare facility. The content of care is not standardized or imposed by the OBESIAL protocol and may vary according to local clinical practices, healthcare professionals' habits, available resources, treatment availability, and therapeutic options accessible within the participating healthcare structures The choice, combination, timing and intensity of these therapeutic options are not determined by the OBESIAL study team. Participants therefore remain under the usual care practices of their healthcare structure throughout the study follow-up, without receiving the standardized multidisciplinary structured care pathway implemented in G1.	Other: Weight loss; The content of care is not standardized or imposed by the OBESIAL protocol and may vary according to local clinical practices, healthcare professionals' habits, available resources, treatment availability, and therapeutic options accessible within the participating healthcare structures. Usual care may include lifestyle and dietary management, physical activity advice or interventions, behavioral support, pharmacological treatment for obesity when clinically indicated and available, including GLP-1 receptor agonist therapy, and other therapeutic options for obesity according to usual clinical practice and individual patient characteristics. Bariatric surgery may also be considered or performed when clinically indicated according to the usual care pathway of the healthcare structure.; Other Names: Non-Structured Usual Care

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Percentage of Participants Achieving ≥5% Weight Loss at Month 18	Percentage of participants achieving a clinically significant weight loss of at least 5% of initial body weight after 18 months of follow-up, compared between participants receiving the structured multidisciplinary obesity care pathway (G1) and those receiving usual non-structured care (G2), under real-world clinical conditions in adults living with obesity in Algeria.	18 months follow-up

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Proportion of participants achieving ≥5% weight loss from randomization baseline at Month 18	Percentage of participants randomized to G1a or G1b who achieve a weight loss of at least 5% from body weight at the time of randomization (Month 6) to Month 18.	From Month 6 to Month 18
Proportion of participants achieving ≥10% weight loss from randomization baseline at Month 18	Percentage of participants randomized to G1a or G1b who achieve a weight loss of at least 10% from body weight at the time of randomization (Month 6) to Month 18.	From Month 6 to Month 18
Proportion of participants achieving ≥15% weight loss from randomization baseline at Month 18	Percentage of participants randomized to G1a or G1b who achieve a weight loss of at least 15% from body weight at the time of randomization (Month 6) to Month 18.	From Month 6 to Month 18
Baseline predictors of weight loss response to semaglutide at Month 18	Association between baseline characteristics measured at Month 6 and weight loss response from Month 6 to Month 18 among participants randomized to G1a. Weight loss response will be defined as achieving ≥5%, ≥10%, or ≥15% reduction in body weight from the randomization baseline. Baseline characteristics will include age, sex, body weight, body mass index, waist circumference, body composition, glycemic parameters, lipid parameters, and obesity-related comorbidities.	From Month 6 to Month 18
Change in glycemic parameters from baseline to Month 18	Changes in fasting plasma glucose and glycated hemoglobin (HbA1c), measured in mmol/L and %, respectively, from baseline (Month 0) to Month 18, comparing participants receiving structured multidisciplinary obesity care (G1) with those receiving usual non-structured care (G2). The evolution of these parameters from Month 6, corresponding to the randomization and initiation of semaglutide in G1a, to Month 18 will also be compared between G1a and G1b to assess the additional effect of semaglutide on glycemic parameters.	Baseline (Month 0) to Month 18 for the G1 versus G2. Month 6 to Month 18 for the G1a versus G1b
Change in lipid parameters from baseline to Month 18	Changes in total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides, measured in mmol/L, from baseline (Month 0) to Month 18, comparing participants receiving structured multidisciplinary obesity care (G1) with those receiving usual non-structured care (G2). The evolution of these parameters from Month 6, corresponding to the randomization and initiation of semaglutide in G1a, to Month 18 will also be compared between G1a and G1b to assess the additional effect of semaglutide on lipid parameters	Baseline (Month 0) to Month 18 for the G1 versus G2.Month 6 to Month 18 for the G1a versus G1b.
Change in body composition from baseline to Month 18	Changes in body fat percentage (%), visceral adipose tissue (VAT) area (cm²), and lean mass index (LMI) (kg/m²) from baseline (Month 0) to Month 18, comparing participants receiving structured multidisciplinary obesity care (G1) with those receiving usual non-structured care (G2). Body composition will be assessed at Months 0, 6, 12, and 18 using bioelectrical impedance analysis and dual-energy X-ray absorptiometry (DXA). Changes in these parameters from Month 6, corresponding to randomization and initiation of semaglutide in G1a, to Month 18 will also be compared between G1a and G1b to assess the additional effect of semaglutide on body composition.	Months 0, 6, 12, and 18; change from Month 0 to Month 18 for G1 versus G2 and from Month 6 to Month 18 for G1a versus G1b

Collaborators and Investigators

• Sponsor: University of Health Sciences, Algeria
• Investigators: Principal Investigator: Mounira Chanegriha, Professor, University of health sciences, Faculty of Medicine, Algiers, Algeria

Study record dates

Study Major Dates

• Study Start (Actual): January 22, 2026
• Primary Completion (Estimated): January 23, 2028
• Study Completion (Estimated): January 23, 2028

Study Registration Dates

• First Submitted: August 11, 2026
• First Submitted That Met QC Criteria: August 18, 2026
• First Posted (Actual): August 21, 2026

Study Record Updates

• Last Update Posted (Actual): August 21, 2026
• Last Update Submitted That Met QC Criteria: August 18, 2026
• Last Verified: August 1, 2026

More Information

Terms related to this study

• Keywords: obesity; GLP-1 receptor agonists; lifestyle interventions; multidisciplinary care; adult obesity
• Additional Relevant MeSH Terms: Nutrition Disorders; Overnutrition; Body Weight; Overweight; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Obesity; Psychotherapy; Behavioral Disciplines and Activities; semaglutide; Behavior Therapy
• Other Study ID Numbers: OBESIAL; MCHA-MED-2026/01 (Other Identifier: Mother and Child hospital of the Army)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

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