Konjac Glucomannan Slows Gastric Emptying and Increases Satiety Hormones GLP-1 and PYY

Higher-viscosity konjac glucomannan slowed gastric emptying, increased satiety hormones (GLP-1, PYY), and reduced appetite in a randomized controlled trial.

Shang, Longchen et al.·Food & function·2020·Moderate Evidencerandomized controlled trial
RPEP-05123Randomized controlled trialModerate Evidence2020RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
randomized controlled trial
Evidence
Moderate Evidence
Sample
N=small
Participants
22 healthy adults (11F/11M), mean age 23.2, mean BMI 20.6

What This Study Found

Higher viscosity konjac glucomannan delayed gastric emptying, increased GLP-1 and PYY secretion, and enhanced subjective satiety compared to lower viscosity or control conditions.

Key Numbers

n=22; hunger p=0.006; fullness p<0.001; desire-to-eat p=0.002; prospective consumption p=0.001; 5 hormones measured (insulin, GLP-1, PYY3-36, CCK-8, ghrelin)

How They Did This

Combined in vitro gastric emptying simulation with a randomized controlled trial in humans. Measured rheological properties, gastric emptying, subjective appetite, glycemia, insulin, GLP-1, PYY, CCK, and ghrelin responses to different KGM viscosities.

Why This Research Matters

Konjac glucomannan is widely used as a dietary supplement for weight management. This study provides mechanistic evidence connecting its viscosity to specific appetite hormone responses and gastric motility effects.

The Bigger Picture

This study connects the physical properties of a dietary fiber (viscosity) to specific gut hormone responses, bridging food science with the GLP-1 pathway that underpins modern weight loss drugs.

What This Study Doesn't Tell Us

Small sample size. Short-term acute testing — chronic effects unknown. In vitro gastric simulator may not fully replicate in vivo digestion. KGM palatability at high viscosity may limit practical intake.

Questions This Raises

  • ?Would sustained konjac glucomannan intake produce clinically meaningful weight loss?
  • ?How does KGM-induced GLP-1 release compare quantitatively to GLP-1 drug therapy?
  • ?Could konjac be formulated to maximize viscosity in the stomach while being palatable?

Trust & Context

Key Stat:
Higher viscosity = more GLP-1 Konjac glucomannan viscosity directly correlates with satiety hormone release and appetite suppression
Evidence Grade:
Moderate — randomized controlled trial with mechanistic hormone data, but small sample and acute (single-meal) design.
Study Age:
Published in 2020; fiber-based appetite regulation continues to be studied alongside pharmaceutical GLP-1 approaches.
Original Title:
In vitro gastric emptying characteristics of konjac glucomannan with different viscosity and its effects on appetite regulation.
Published In:
Food & function, 11(9), 7596-7610 (2020)
Database ID:
RPEP-05123

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study
What do these levels mean? →

Frequently Asked Questions

What is konjac glucomannan?

A highly viscous dietary fiber from the konjac plant root, commonly used in Asian cuisine and available as a weight loss supplement. It absorbs water and forms a gel in the stomach, which this study shows triggers satiety hormone release.

How does konjac fiber relate to GLP-1 drugs like Ozempic?

Both stimulate GLP-1 release, but through different mechanisms. Konjac triggers GLP-1 naturally by slowing digestion and stimulating gut cells, while drugs like semaglutide directly activate GLP-1 receptors. The fiber effect is much milder than pharmaceutical GLP-1.

Read More on RethinkPeptides

Cite This Study

RPEP-05123·https://rethinkpeptides.com/research/RPEP-05123

APA

Shang, Longchen; Wang, Yi; Ren, Yanyan; Ai, Tingyang; Zhou, Peiyuan; Hu, Ling; Wang, Ling; Li, Jing; Li, Bin. (2020). In vitro gastric emptying characteristics of konjac glucomannan with different viscosity and its effects on appetite regulation.. Food & function, 11(9), 7596-7610. https://doi.org/10.1039/d0fo01104e

MLA

Shang, Longchen, et al. "In vitro gastric emptying characteristics of konjac glucomannan with different viscosity and its effects on appetite regulation.." Food & function, 2020. https://doi.org/10.1039/d0fo01104e

RethinkPeptides

RethinkPeptides Research Database. "In vitro gastric emptying characteristics of konjac glucoman..." RPEP-05123. Retrieved from https://rethinkpeptides.com/research/shang-2020-in-vitro-gastric-emptying

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.