Effect of Glucomannan Supplementation on Body Weight in Overweight and Obese Children

Effect of Glucomannan Supplementation on Body Weight in Overweight and Obese Children: A Randomized Controlled Trial

Glucomannan (GNN), a water-soluble dietary fiber derived from the plant Amorphophallus konjac, is marketed for weight reduction. The exact mechanisms by which GNN might exert its actions are unclear. Nonetheless, it has been shown that GNN slows gastric emptying by forming a viscous gel of large volume, which increases the feeling of satiety. Current evidence on the effectiveness of GNN for weight reduction is sparse, and well-designed trials performed in children are needed to assess the efficacy of this modality. We aim to systematically evaluate the efficacy of GNN consumption for the management of overweight and obesity in children.

Study Overview

• Status: Completed
• Conditions: Obesity; Overweight
• Intervention / Treatment: Dietary supplement: Maltodextrin; Dietary supplement: Glucomannan

Detailed Description

Methods and analysis

Children aged 6 to 17 years with overweight and obesity (based on the WHO growth criteria) will be randomly assigned to receive GNN or placebo (maltodextrin) (both at a dose of 3 g/day) for 3 months and will be followed up for 3 months. Prior to the intervention, all children will receive dietetic advice, and they will be encouraged to engage in physical activity. The primary outcome measure will be the BMI-for-age z-score difference between the groups at the end of the intervention.

• Study Type: Interventional
• Enrollment (Actual): 96
• Phase: Phase 4

Contacts and Locations

Study Locations

• Poland
  • Mazowieckie
    • Warsaw, Mazowieckie, Poland, 02-091
      • The Medical University of Warsaw, Department of Paediatrics

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 2 years to 13 years (Child)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• age 6-17 years;
• overweight or obesity based on the WHO (World Health Organization) growth charts/references (>+1 standard deviation [SD] or >+2 SD, respectively)

Exclusion Criteria:

• drug therapy for a chronic disease (including drugs that influence appetite or body weight);
• type 1 or 2 diabetes;
• history of surgical treatment of obesity;
• participation in another program for treating obesity during the project and/or 3 months prior to recruitment;
• secondary causes of obesity;
• pregnancy.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Glucomannan; Glucomannan orally, 3g/day (in three divided doses), for 12 weeks	Dietary supplement: Glucomannan; Other Names: Amorphophallus konjac
Placebo Comparator: Maltodextrin; Maltodextrin orally, 3g/day (in three divided doses), for 12 weeks	Dietary supplement: Maltodextrin

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
BMI-for-age z-score difference	Baseline versus end of the intervention	0-12 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Body composition	Whole body fat, central body fat, fat-free mass (grams) assessed by a dual energy X-ray absorption (DXA)	0-13 weeks
BMI-for-age z-score difference	Baseline versus end of the follow-up	0-24 weeks
Proportion of participants with dyslipidemia	Proportion of participants with dyslipidemia from baseline to week 12 and week 24 (mean change, SD)	At baseline, 12 weeks and 24 weeks
Proportion of participants with impaired fasting plasma glucose (FPG)	Proportion of participants with impaired fasting plasma glucose (FPG) from baseline to week 12 and week 24 (mean change, SD).	At baseline, 12 weeks and 24 weeks
Energy intake (kJ/d)	Based on self-written, 3-day food records	At baseline and at week 12, week 24.
Physical activity	Measured using an accelerometer	at baseline and at week 12
Adverse events		0-12 weeks
Blood pressure (systolic and diastolic)	The mean change from baseline to week 12, and week 24	Baseline, week 12, 24 weeks.

Collaborators and Investigators

• Sponsor: Medical University of Warsaw
• Investigators: Principal Investigator: Bartlomiej M Zalewski, MD, The Medical University of Warsaw; Study Chair: Hanna Szajewska, Professor, The Medical University of Warsaw

Publications and helpful links

General Publications

• Zalewski BM, Szajewska H. No Effect of Glucomannan on Body Weight Reduction in Children and Adolescents with Overweight and Obesity: A Randomized Controlled Trial. J Pediatr. 2019 Aug;211:85-91.e1. doi: 10.1016/j.jpeds.2019.03.044. Epub 2019 Apr 26.
• Zalewski BM, Szajewska H. Effect of glucomannan supplementation on body weight in overweight and obese children: protocol of a randomised controlled trial. BMJ Open. 2015 Apr 13;5(4):e007244. doi: 10.1136/bmjopen-2014-007244.

Study record dates

Study Major Dates

• Study Start (Actual): April 27, 2015
• Primary Completion (Actual): January 2, 2018
• Study Completion (Actual): March 28, 2018

Study Registration Dates

• First Submitted: October 29, 2014
• First Submitted That Met QC Criteria: October 30, 2014
• First Posted (Estimate): October 31, 2014

Study Record Updates

• Last Update Posted (Actual): July 20, 2018
• Last Update Submitted That Met QC Criteria: July 19, 2018
• Last Verified: October 1, 2017

More Information

Terms related to this study

• Keywords: treatment; obesity; overweight; children; adolescents; glucomannan
• Additional Relevant MeSH Terms: Overweight; Body Weight; Gastrointestinal Agents; Cathartics; (1-6)-alpha-glucomannan
• Other Study ID Numbers: 07-2014