Noodles made with 30% RD43 rice flour significantly increased GLP-1 and PYY hormone levels while reducing blood sugar and appetite in humans.
GLP-1 & PYY up at 30 minBoth satiety peptide hormones were significantly elevated 30 minutes after eating rice flour noodles, alongside lower blood sugar at 15–90 minutes.
What the researchers found
Noodles prepared with 30% RD43 rice flour substitution significantly lowered postprandial plasma glucose at 15–90 minutes compared to control noodles. At the same time, the modified noodles significantly increased circulating levels of two key satiety peptide hormones — GLP-1 (glucagon-like peptide-1) and PYY (peptide tyrosine-tyrosine) — at 30 minutes after consumption.
Participants also reported significantly lower desire to eat and higher fullness lasting up to 120 minutes after consuming the RD43 rice noodles. The food science analysis showed that increasing RD43 rice flour content from 10–40% progressively reduced starch digestibility and rapidly digestible starch while increasing undigestible starch. Importantly, the 30% substitution level maintained similar overall sensory acceptability to conventional noodles.
Why it matters
Finding ways to naturally stimulate the body's own satiety hormones through everyday foods — rather than injectable drugs — could offer a practical, population-level approach to managing blood sugar and controlling appetite. This is especially relevant given the growing interest in GLP-1 as a therapeutic target for diabetes and obesity.
The numbers in context
30% RD43 rice flour; GLP-1 and PYY increased at 30 min; glucose lower at 15-90 min; desire to eat decreased and fullness increased until 120 min; similar overall acceptability
How the study worked
This was a combined food science and human crossover study. Researchers first developed noodles with 10–40% RD43 rice flour substitution and characterized their starch digestibility, physicochemical properties, and sensory attributes. They then conducted a human meal test comparing 30% RD43 rice noodles against control noodles, measuring postprandial blood glucose, GLP-1, PYY, and subjective appetite ratings over time.
Who was studied
Human crossover study of meal response to 30% RD43 rice flour noodles vs control noodles
What this study cannot tell us
The sample size for the human study was not specified in the abstract, so the statistical power is unclear. This was an acute single-meal test, not a long-term dietary intervention, so it's unknown whether the effects persist with regular consumption. Only one rice variety (RD43) was tested, and cultural food preferences may limit how widely rice flour noodles could be adopted outside Asian populations.
How to read the evidence
This is a moderate-evidence study combining food characterization with a human crossover trial. While the crossover design is a strength, the unspecified sample size and acute (single-meal) nature of the human component limit the strength of conclusions about long-term effects.
When this study was published
Published in 2021, this study is relatively recent and aligns with the growing interest in food-based approaches to modulating GLP-1 and other gut peptide hormones.
The bigger picture
GLP-1 receptor agonists like semaglutide have revolutionized diabetes and obesity treatment, but they require injections and can be expensive. This study explores the other side of the equation — whether modifying common foods can naturally boost the body's own GLP-1 and PYY production. While the effects are modest compared to pharmaceutical GLP-1RAs, food-based approaches could complement drug therapy or serve as preventive strategies for at-risk populations.
Questions still open
- Would regular daily consumption of RD43 rice flour noodles produce sustained improvements in appetite control and blood sugar management over weeks or months?
- How do the magnitudes of GLP-1 and PYY increases from these noodles compare to those from pharmaceutical GLP-1 receptor agonists?
- Could this approach be applied to other staple foods beyond noodles, such as bread or rice dishes?
Common questions
How do RD43 rice flour noodles affect satiety hormones?
Do the modified noodles taste different from regular noodles?
Read the original research
RD43 rice flour: the effect on starch digestibility and quality of noodles, glycemic response, short-acting satiety hormones and appetite control in humans.
Food & function, 12(17), 7975-7985
Citation
Suklaew, Phim On; Chusak, Charoonsri; Wang, Chin-Kun; Adisakwattana, Sirichai. (2021). RD43 rice flour: the effect on starch digestibility and quality of noodles, glycemic response, short-acting satiety hormones and appetite control in humans.. Food & function, 12(17), 7975-7985. https://doi.org/10.1039/d1fo01389k