Health Assessment of Low Glycaemic Index - High Protein Rice to Enhance Glycemic Control Through Nutrition (HARVEST)

September 11, 2026 updated by: Johan Eriksson, Institute for Human Development and Potential (IHDP), Singapore

Health Assessment of Low Glycaemic Index - High Protein Rice to Enhance Glycemic Control Through Nutrition (HARVEST) Study

Type 2 Diabetes (T2D) represents a critical public health challenge in Singapore, with prevalence projected to reach one million residents by 2050. This epidemic is largely driven by a distinct "Asian phenotype" characterized by reduced insulin secretion capacity even at lower BMIs and a diet heavily centered on high-glycemic index (GI) white rice. While brown rice offers superior nutritional benefits, its global and local adoption remains low due to entrenched cultural preferences, shorter shelf life, and sensory barriers.

While the link between high-GI carbohydrates and metabolic dysfunction is well-documented, there is limited clinical evidence on the effects of "functional" white rice varieties specifically those engineered to combine low GI properties with significantly enhanced protein content on long-term glycemic control, metabolic and gut microbiome health in Asian populations. The importance of this research lies in its evaluation of a culturally seamless substitution strategy. By replacing conventional white rice with Low-GI (LGI) and High-Protein Low-GI (LGI-HP) varieties, the HARVEST study addresses the metabolic burden of prediabetes without requiring major behavioral shifts. The findings will provide vital mechanistic insights into glucose regulation, insulin sensitivity, and microbial dysbiosis, to provide the evidence based for nutritional strategies for T2D prevention and management.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

  1. To evaluate the efficacy of a 16-week intervention with functional rice varieties (LGI, LGI-HP) on chronic glycaemic management in Singaporean adults with prediabetes. It is hypothesized that dietary replacement of habitual rice with functional varieties can significantly improve metabolic health compared to the high-GI (HGI) control group
  2. To compare the postprandial glucose and insulin responses of LGI, LGI-HP and HGI rice under standardized acute meal testing using continuous glucose monitoring. It is hypothesized that postprandial glucose excursions and glycemic variability will be significantly attenuatated in the functional rice groups compared to the HGI group
  3. To characterise longitudinal shifts in gut microbiota composition and identify mechanistic correlations between microbial changes and glucose metabolism. It is hypothesized that long term consumption of functional rice will promote beneficial shift in the gut microbiome which are associated with improved glucose homeostasis.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
225

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Males or females, aged 40 to 65 years old
  2. Chinese, Malay or Indian
  3. Body Mass Index between 23.0 - 32.0 kg/m2
  4. Prediabetes profile as per fasting plasma glucose (≤ 6.9 mmol/L) and HbA1c level (5.7% - 6.4%)
  5. Habitually consuming about 3 to 5 servings of polished white rice per day
  6. No known food allergies and intolerance to food provided as part of study procedures
  7. Proficient in English language
  8. Willing to comply to study procedures and provide written consent

Exclusion Criteria:

  1. Diagnosed with Type 1 or 2 diabetes mellitus/ OGTT failure during screening visit
  2. History or current diagnosis of cardiovascular, endocrine, gastrointestinal, haematological, hepatitis (hepatitis B and C), cancers (except basal cell carcinoma), chronic kidney disease or other medical conditions which may affect study outcomes, as assessed by study team
  3. Having chronic medication (eg: metformin, oral corticosteroids etc), and/or supplements that may influence glycaemic management and other study outcomes, as assessed by study team
  4. History of bariatric surgery
  5. Significant weight change (± 5 % body weight) during the last 3 months
  6. Women who are pregnant, breastfeeding or planning pregnancy
  7. Drug abuse within the last 5 years
  8. Excessive alcohol consumption > 2 servings per day
  9. Smoking in the last 1 year
  10. Following any special diet(s) which may interfere with study outcomes (eg: Ketogenic diet, intermittent fasting, calorie-deficit)
  11. Major change in physical activity and/or dietary habits in the last 3 months
  12. Use of oral antibiotics in the last 3 months
  13. Participation in other intervention studies, which may affect study outcomes as assessed by study team
  14. Staff of IHDP and SIFBI in A*STAR

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: High glycaemic index rice (HGI)
Participants will replace their habitual rice consumption with 4 servings (equivalent to approximately 2 bowls or ~400 g of cooked rice) per day of HGI rice while keeping other dietary components consistent.
Dietary supplement: Functional rice variaties
Single-blinded, 16 week parallel randomized controlled trial (RCT) involving 225 participants with prediabetes. Participants are randomized into one of three arms to consume either high glycaemic index rice (HGI), low glycaemic index rice (LGI), or low glycaemic index high protein rice (LGI-HP). In each arm (n = 75), participants will replace their habitual rice consumption with 4 servings (equivalent to approximately 2 bowls or ~400 g of cooked rice) per day of the assigned rice group while keeping other dietary components consistent.
Experimental: Low glycaemic index rice (LGI)
Participants will replace their habitual rice consumption with 4 servings (equivalent to approximately 2 bowls or ~400 g of cooked rice) per day of LGI rice while keeping other dietary components consistent.
Dietary supplement: Functional rice variaties
Single-blinded, 16 week parallel randomized controlled trial (RCT) involving 225 participants with prediabetes. Participants are randomized into one of three arms to consume either high glycaemic index rice (HGI), low glycaemic index rice (LGI), or low glycaemic index high protein rice (LGI-HP). In each arm (n = 75), participants will replace their habitual rice consumption with 4 servings (equivalent to approximately 2 bowls or ~400 g of cooked rice) per day of the assigned rice group while keeping other dietary components consistent.
Experimental: Low glycaemic index high protein rice (LGI-HP)
Participants will replace their habitual rice consumption with 4 servings (equivalent to approximately 2 bowls or ~400 g of cooked rice) per day of LGI-HP rice while keeping other dietary components consistent.
Dietary supplement: Functional rice variaties
Single-blinded, 16 week parallel randomized controlled trial (RCT) involving 225 participants with prediabetes. Participants are randomized into one of three arms to consume either high glycaemic index rice (HGI), low glycaemic index rice (LGI), or low glycaemic index high protein rice (LGI-HP). In each arm (n = 75), participants will replace their habitual rice consumption with 4 servings (equivalent to approximately 2 bowls or ~400 g of cooked rice) per day of the assigned rice group while keeping other dietary components consistent.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in Haemoglobin A1c (HbA1c) levels
Time Frame: 16 weeks
To evaluate the efficacy of a 16-week intervention with functional rice varieties on chronic glycaemic management in Singaporean adults with prediabetes, as measured by change in Haemoglobin A1c (HbA1c) levels.
16 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Institute for Human Development and Potential (IHDP), Singapore

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Novo Nordisk A/S

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Johan G. Eriksson, MD, A*STAR Institute for Human Development and Potential (A*STAR IHDP)

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
October 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
April 30, 2029

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
April 30, 2029

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 17, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 17, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 23, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
September 15, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
September 11, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
September 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • HARVEST
  • NNF25SA0112673 (Other Grant/Funding Number: Novo Nordisk Foundation)

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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