Safety and efficacy of glucomannan for weight loss in overweight and moderately obese adults.
BACKGROUND
Few safe and effective dietary supplements are available to promote weight loss. We evaluated the safety and efficacy of glucomannan, a water-soluble fiber supplement, for achieving weight loss in overweight and moderately obese individuals consuming self-selected diets.


METHODS
Participants were randomly assigned to take 1.33 grams of glucomannan or identically looking placebo capsules with 236.6 mL (8 ounces) of water one hour before breakfast, lunch, and dinner for 8 weeks. The primary efficacy outcome was change in body weight after 8 weeks. Other efficacy outcomes were changes in body composition, hunger/fullness, and lipid and glucose concentrations. Safety outcomes included gastrointestinal symptoms/tolerance and serum liver enzymes and creatinine levels.


RESULTS
A total of 53 participants (18-65 years of age; BMI 25-35 kg/m²) were enrolled and randomized. The two groups did not differ with respect to baseline characteristics and compliance with the study supplement. At 8 weeks, there was no significant difference between the glucomannan and placebo groups in amount of weight loss (-.40 ± .06 and -.43 ± .07, resp.) or other efficacy outcomes or in any of the safety outcomes.


CONCLUSIONS
Glucomannan supplements administered over 8 weeks were well tolerated but did not promote weight loss or significantly alter body composition, hunger/fullness, or lipid and glucose parameters. This trial is registered with NCT00613600.
Rush University College of Nursing, 600 S. Paulina Street, Suite 1080, Chicago, IL 60612, USA.
Joyce K
JK
Keithley
Rush University College of Nursing, 600 S. Paulina Street, Suite 1080, Chicago, IL 60612, USA.
Barbara
B
Swanson
Rush University Medical Center, 1725 W. Harrison Street, Chicago, IL 60612, USA.
Susan L
SL
Mikolaitis
Section of Gastroenterology and Nutrition, Rush University Medical Center, 1725 W. Harrison Street, Chicago, IL 60612, USA.
Mark
M
DeMeo
North Park University School of Nursing, 3225 W. Foster Avenue, Chicago, IL 60625, USA.
Janice M
JM
Zeller
Community, Systems, and Mental Health Nursing, Rush University College of Nursing, 600 S. Paulina Street, Suite 1080, Chicago, IL 60612, USA.
Lou
L
Fogg
Faculty Practice, Rush University College of Nursing, 600 S. Paulina Street, Suite 1080, Chicago, IL 60612, USA.
Jehan
J
Adamji
D000293:Adolescent; D000328:Adult; D000368:Aged; D001823:Body Composition; D015992:Body Mass Index; D002400:Cathartics / Q000008:administration & dosage / Q000627:therapeutic use*; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D008297:Male; D008351:Mannans / Q000008:administration & dosage / Q000627:therapeutic use*; D008875:Middle Aged; D009765:Obesity / Q000188:drug therapy* / Q000517:prevention & control; D017211:Treatment Failure; D015431:Weight Loss / Q000187:drug effects*
D002400:Cathartics; D008351:Mannans; C022901:(1-6)-alpha-glucomannan