Body Weight Reduction and Metabolic/Biochemical Parameters in Overweight or Obesity

The Effect of Body Weight Reduction on Selected Metabolic and Biochemical Parameters in Individuals With Overweight or Obesity

This was a single-center prospective observational cohort study conducted in Poland in the context of routine metabolic outpatient care. The study assessed selected metabolic, biochemical, oxidative-stress, inflammatory, and body-composition parameters in individuals with overweight or obesity undergoing standard lifestyle-based body weight reduction management. Participants with BMI > 25 kg/m² were followed before and after body weight reduction, while individuals with normal body weight served as a comparison group. The weight reduction management included individualized dietary recommendations, physical-activity guidance, health education, regular follow-up visits, fasting blood sampling, and body-composition assessment. The aim of the study was to evaluate whether body weight reduction is associated with changes in metabolic and biochemical parameters, with particular attention to glucose and lipid metabolism, oxidative stress, inflammatory markers, adipokines, cytokines, and body-composition changes.

Study Overview

• Status: Completed
• Conditions: Abdominal Obesity-Metabolic Syndrome; Overweight , Obesity
• Intervention / Treatment: Behavioral: Routine Lifestyle-Based Weight Reduction Management

Detailed Description

This was a single-center prospective observational cohort study conducted at the Medical University of Silesia in Katowice, Poland, and in a metabolic outpatient clinic in Miasteczko Śląskie, Poland. The study was designed to evaluate the effect of body weight reduction on selected metabolic, biochemical, oxidative-stress, inflammatory, and body-composition parameters in individuals with overweight or obesity.

The study was conducted in the context of routine metabolic outpatient care. Participants with overweight or obesity received standard lifestyle-based body weight reduction management, including individualized dietary recommendations, physical-activity guidance, health education, and regular follow-up visits. The investigators did not assign participants to an investigational medicinal product, medical device, dietary supplement, surgical procedure, pharmacological intervention, or experimental therapy. The study prospectively observed participants receiving routine lifestyle-based weight reduction management and assessed changes in clinical and laboratory parameters before and after body weight reduction.

The approved study protocol planned the inclusion of individuals with overweight or obesity and a normal-weight comparison group. Participants with BMI > 25 kg/m² were evaluated in relation to body weight reduction, while individuals with normal body weight served as a comparison group for selected baseline analyses. Patients with overweight or obesity were assessed by medical examination, dietary and clinical questionnaires, anthropometric measurements, body-composition analysis, and fasting blood sampling. Body-composition analysis included assessment of body weight, fat mass, fat-free mass, skeletal muscle mass, total body water, visceral fat, and related parameters. Blood samples were collected for biochemical analyses, including markers of glucose metabolism, lipid metabolism, oxidative stress, antioxidant status, inflammatory markers, adipokines, cytokines, chemokines, growth factors, and selected cardiovascular-risk parameters.

Participants with overweight or obesity were followed during standard body weight reduction management until clinically relevant weight reduction or achievement of optimal body weight. According to the original study documentation, assessments were planned before the start of weight reduction, after approximately 10% body weight reduction, and after approximately 20% body weight reduction or achievement of target body weight. Follow-up visits included body weight measurements, waist and hip circumference measurements, dietary counselling, education regarding caloric intake, and motivation to continue lifestyle modification.

The primary objective of the study was to assess whether body weight reduction in individuals with overweight or obesity is associated with changes in selected metabolic and biochemical parameters. Secondary objectives included evaluation of oxidative-stress and antioxidant-status parameters, glucose and lipid metabolism, inflammatory markers, adipokines, cytokines, and body-composition changes. The study also aimed to assess relationships between biochemical parameters and body-composition indices before and after body weight reduction.

The study was approved by the Bioethics Committee of the Medical University of Silesia in Katowice, Poland. All participants received information about the study and provided written informed consent before participation. This ClinicalTrials.gov record is submitted retrospectively to meet journal publication requirements and to provide transparent public information about the completed study.

• Study Type: Observational
• Enrollment (Actual): 53

Contacts and Locations

Study Locations

• Poland
  • Silesian Voivodeship
    • Miasteczko Śląskie, Silesian Voivodeship, Poland, 42-610
      • Eko-Prof-Med Medical Center, Metabolic Outpatient Clinic
    • Zabrze, Silesian Voivodeship, Poland, 41-808
      • Department of Biochemistry, Faculty of Medical Sciences in Zabrze, Medical University of Silesia in Katowice

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

Adults with overweight or obesity who received routine lifestyle-based body weight reduction management in a metabolic outpatient clinic in Miasteczko Śląskie, Poland, and who provided written informed consent for participation in the study.

Description

Inclusion Criteria:

• Adults aged 18-85 years
• BMI > 25 kg/m²
• Overweight or obesity diagnosed on the basis of medical examination and body-composition assessment
• Participation in routine lifestyle-based body weight reduction management in a metabolic outpatient clinic
• Written informed consent to participate in the study

Exclusion Criteria:

• Lack of informed consent
• Severe hepatic insufficiency
• Severe renal insufficiency
• Severe respiratory insufficiency
• Severe circulatory insufficiency
• Disturbances of consciousness
• Treatment-resistant depression
• Chronic alcohol abuse
• Pregnancy
• History of serious nervous system injury
• Implanted cardiac pacemaker
• Pharmacological treatment affecting glucose and/or lipid metabolism
• Incomplete follow-up or incomplete laboratory data

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Individuals With Overweight or Obesity; Adults with BMI > 25 kg/m² who were receiving routine lifestyle-based body weight reduction management in a metabolic outpatient clinic. Participants were prospectively observed and assessed before and after body weight reduction. Assessments included clinical and dietary questionnaires, anthropometric measurements, body-composition analysis, fasting blood sampling, and biochemical, metabolic, oxidative-stress, inflammatory, adipokine, and cytokine measurements.

Behavioral: Routine Lifestyle-Based Weight Reduction Management; Standard lifestyle-based body weight reduction management received as part of routine metabolic outpatient care. It included individualized dietary recommendations, physical-activity guidance, health education, and regular follow-up visits. Participants were not assigned to this management as part of the study; the study prospectively observed patients receiving routine care and assessed metabolic, biochemical, inflammatory, oxidative-stress, adipokine, cytokine, and body-composition parameters before and after body weight reduction.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Body Weight	Change in body weight from baseline to follow-up after routine lifestyle-based body weight reduction management.	Baseline and after body weight reduction, up to approximately 6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Body Fat Mass	Change in body fat mass assessed by bioelectrical impedance analysis and expressed in kilograms.	Baseline and after body weight reduction, up to approximately 6 months
Change in Glucose concentration in mg/dl.	Changes in fasting glucose.	Baseline and after body weight reduction, up to approximately 6 months
Change in total-cholesterol concentration in mg/dl.	Changes in total cholesterol concentration.	Baseline and after body weight reduction, up to approximately 6 months
Change in malondialdehyde concentration in μmol/l.	Change in blood malondialdehyde concentration, assessed as a marker of lipid peroxidation and oxidative stress, from baseline to follow-up after body weight reduction.	Baseline and after body weight reduction, up to approximately 6 months
Change in serum IL-6 concentration in pg/ml.	Change in serum interleukin-6 (IL-6) concentration from baseline to follow-up after body weight reduction. IL-6 was measured in serum samples as a marker of systemic low-grade inflammation and expressed in pg/ml.	Baseline and after body weight reduction, up to approximately 6 months

Collaborators and Investigators

• Sponsor: Medical University of Silesia
• Investigators: Principal Investigator: Sławomir Kasperczyk, Prof, Medical University of Silesia in Katowice

Publications and helpful links

General Publications

• Szlachta B, Birkova A, Cizmarova B, Glogowska-Gruszka A, Zalejska-Fiolka P, Dydon M, Zalejska-Fiolka J. Erythrocyte Oxidative Status in People with Obesity: Relation to Tissue Losses, Glucose Levels, and Weight Reduction. Antioxidants (Basel). 2024 Aug 7;13(8):960. doi: 10.3390/antiox13080960.
• Szlachta B, Birkova A, Wielkoszynski T, Gospodarczyk A, Hubkova B, Dydon M, Zalejska-Fiolka J. Serum Oxidative Status in People with Obesity: Relation to Tissue Losses, Glucose Levels, and Weight Reduction. Antioxidants (Basel). 2023 Oct 27;12(11):1923. doi: 10.3390/antiox12111923.
• Zalejska-Fiolka J, Birkova A, Hubkova B, Wielkoszynski T, Cizmarova B, Szlachta B, Fiolka R, Blaszczyk U, Wylegala A, Kasperczyk S, Grzanka A, Marekova M, Toborek M. Successful correction of hyperglycemia is critical for weight loss and a decrease in cardiovascular risk in obese patients. J Nutr Biochem. 2022 Aug;106:109021. doi: 10.1016/j.jnutbio.2022.109021. Epub 2022 Apr 25.
• Zalejska-Fiolka J, Birkova A, Wielkoszynski T, Hubkova B, Szlachta B, Fiolka R, Blaszczyk U, Kuzan A, Gamian A, Marekova M, Toborek M. Loss of Skeletal Muscle Mass and Intracellular Water as Undesired Outcomes of Weight Reduction in Obese Hyperglycemic Women: A Short-Term Longitudinal Study. Int J Environ Res Public Health. 2022 Jan 17;19(2):1001. doi: 10.3390/ijerph19021001.
• Zalejska-Fiolka J, Hubkova B, Birkova A, Velika B, Puchalska B, Kasperczyk S, Blaszczyk U, Fiolka R, Bozek A, Maksym B, Marekova M, Birkner E. Prognostic Value of the Modified Atherogenic Index of Plasma during Body Mass Reduction in Polish Obese/Overweight People. Int J Environ Res Public Health. 2018 Dec 27;16(1):68. doi: 10.3390/ijerph16010068.

Study record dates

Study Major Dates

• Study Start (Actual): May 10, 2016
• Primary Completion (Actual): September 30, 2022
• Study Completion (Actual): September 30, 2022

Study Registration Dates

• First Submitted: June 2, 2026
• First Submitted That Met QC Criteria: June 8, 2026
• First Posted (Actual): June 12, 2026

Study Record Updates

• Last Update Posted (Actual): June 12, 2026
• Last Update Submitted That Met QC Criteria: June 8, 2026
• Last Verified: June 1, 2026

More Information

Terms related to this study

• Keywords: obesity; overweight; lipid metabolism; body composition; oxidative stress; metabolic syndrome; cytokines; inflammatory markers; glucose metabolism; abdominal obesity; adipokines; body weight reduction
• Additional Relevant MeSH Terms: Nutrition Disorders; Metabolic Diseases; Overnutrition; Body Weight; Glucose Metabolism Disorders; Insulin Resistance; Hyperinsulinism; Pathological Conditions, Signs and Symptoms; Nutritional and Metabolic Diseases; Signs and Symptoms; Overweight; Obesity; Metabolic Syndrome; Obesity, Abdominal; Abdominal obesity metabolic syndrome
• Other Study ID Numbers: KNW/0022/KB1/19/I/16; Secondary ID: KNW-1-016/N/7/2 (Other Grant/Funding Number: Medical University of Silesia); Secondary ID: KNW-1/109/K/8/Z (Other Identifier: Medical University of Silesia); Secondary ID: KNW-1/171/K/9/O (Other Identifier: Medical University of Silesia); Secondary ID: PCN-1-049/K/0/O (Other Identifier: Medical University of Silesia); Secondary ID: PCN-1-018/K/1/O (Other Identifier: Medical University of Silesia); Secondary ID: PCN-1-132/K/2/O (Other Identifier: Medical University of Silesia)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be made publicly available because of privacy and confidentiality restrictions, limitations of the original informed consent, and the retrospective registration of this completed study. De-identified aggregate data or non-identifiable datasets may be made available from the investigators upon reasonable request, subject to institutional approval and applicable data protection regulations.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No