Legume Flour Particle Size and Metabolic Responses to Bread (PULSE)

Effects of Legume Flour Particle Size on Postprandial Metabolic Responses to Bread of Healthy Subjects and Patients With Type 2 Diabetes

The aim of the study is to investigate the effect of partial replacement of wheat flour by legume flour of different particle sizes on postprandial glucose responses and appetite sensations in healthy subjects and patients with type 2 diabetes.

Subjects will consume a portion of bread enriched with legume flours yielding 50 g of available carbohydrates as breakfast meal. To investigate the effect of the bread on glycemic response, a continuous glucose monitoring system (CGM) will be used. After an 180-min period, subjects will be given a second meal and glycemic response will be monitored for another 180 min. During the trial subjects must fill appropriate visual analogue scales regarding appetite sensations.

Study Overview

• Status: Recruiting
• Conditions: Type 2 Diabetes
• Intervention / Treatment: Dietary supplement: Conventional white wheat bread; Dietary supplement: Wheat bread with 30% finely milled chickpea flour; Dietary supplement: Wheat bread with 30% coarse chickpea flour

Detailed Description

The clinical trial will include two groups: (a) apparently healthy adults (up to 35 years old) and (b) individuals diagnosed with T2DM (aged 40-65 years). The study will investigate the effect of flour particle size on postprandial glycemic responses to bread and appetite sensations.

Within the framework of the clinical study, a total of three bread products will be prepared. Their final recipes will be determined after a series of tests to ensure the desired properties and organoleptic characteristics.

Intervention 1: White wheat bread with conventional fine wheat flour Intervention 2: White wheat bread with the addition of 30% finely milled chickpea flour Intervention 3: White wheat bread with the addition of 30% chickpea flour of larger particle size (>1.6 mm)

Inclusion and Exclusion Criteria

1. Group 1

   Participants in Group 1 will be men and women aged 40-65 years with BMI < 31 kg/m², fasting glucose > 125 mg/dL, and HbA1c < 8.5%, diagnosed with T2DM for at least one year before entering the study.

   Patients must be on stable treatment (hypoglycemic, lipid-lowering, antihypertensive) for at least 3 months prior to enrolment. Most participants will be individuals monitored at the Diabetes Clinic of the 1st Propaedeutic Department of Internal Medicine at Laiko General Hospital.

   Individuals with conditions that could affect study outcomes (e.g., endocrine, cardiovascular, pulmonary, renal, or gastrointestinal disorders), those with sensitivity, intolerance, or allergy to any bread ingredients used in the clinical trial, pregnant or breastfeeding women, individuals with eating disorders, and those taking medications or supplements considered incompatible with the study will be excluded.

2. Group 2

Group 2 will consist of apparently healthy men and women aged 18-35 years with BMI 18-25 kg/m², who are not following a diet program or dietary counseling during the study period.

Individuals with fasting glucose > 110 mg/dL, blood pressure > 160/100 mmHg, metabolic or dietary disorders, conditions that could affect the study outcomes (e.g., endocrine, cardiovascular, pulmonary, renal, or gastrointestinal diseases), those with sensitivity, intolerance, or allergy to the bread ingredients used, pregnant or breastfeeding women, and those taking medications that could affect the study (e.g., hypoglycemic drugs, appetite-modifying medications, or any other relevant medications) will be excluded.

All volunteers, after providing informed written consent, will undergo a blood sample collection to confirm eligibility based on defined criteria, as well as for additional hematological and biochemical analyses. Subsequently, each participant will have a Continuous Glucose Monitoring (CGM) sensor placed by trained personnel according to the manufacturer's instructions, in order to monitor glucose values throughout the postprandial protocol. Measurements will include the period following consumption of the first meal (bread) and a second standardized meal, consumed 3 h later.

• Study Type: Interventional
• Enrollment (Estimated): 35
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Maria Christina Kanata, MSc; Phone Number: +306937900141; Email: mckanata@hua.gr
• Study Contact Backup: Name: Amalia E Yanni, PhD; Email: ayanni@hua.gr

Study Locations

• Greece
  • Attica
    • Athens, Attica, Greece, 17676
      • Recruiting
      • Harokopio University
      • Contact: Amalia E Yanni, PhD; Phone Number: 2109549174; Email: ayanni@hua.gr
    • Athens, Attica, Greece
      • Recruiting
      • 1st Department of Propaedeutic Internal Medicine, Medical School, National and Kapodistrian University of Athens, Laiko General Hospital, 15772 Athens, Greece

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Cohort Healthy Participants

Inclusion Criteria:

• Age: Adults aged 18-35 years.
• Health Status: Healthy individuals with no diagnosed chronic diseases, including diabetes, cardiovascular disease, or gastrointestinal disorders.
• Body Mass Index (BMI): 18.5-27 kg/m² (normal to overweight range).
• Fasting Glucose: Normal fasting plasma glucose (<100 mg/dL or <5.6 mmol/L).
• No regular use of medications known to affect glucose metabolism (e.g., insulin, metformin, corticosteroids).
• Ability and willingness to comply with study procedures, including continuous glucose monitoring and standardized test meals.
• Informed Consent: Ability to understand and provide written informed consent.

Exclusion Criteria:

• Diagnosed chronic diseases: Diabetes (type 1 or type 2), cardiovascular disease, kidney or liver disease, gastrointestinal disorders (e.g., celiac disease, inflammatory bowel disease).
• Abnormal glucose metabolism: Fasting plasma glucose ≥100 mg/dL (≥5.6 mmol/L) or HbA1c ≥5.7%.
• Medication use: Regular use of medications that affect glucose metabolism, insulin sensitivity, or digestion (e.g., metformin, corticosteroids, GLP-1 analogs).
• Allergies or intolerances: Allergy or intolerance to wheat, chickpeas, gluten, or other ingredients used in the study foods.
• Pregnancy or lactation: Women who are pregnant, breastfeeding, or planning pregnancy during the study period.
• Recent major weight change: Significant weight loss or gain (>5% body weight) in the past 3 months.
• Extreme physical activity: Competitive athletes or individuals engaging in extreme exercise regimens that could influence glucose metabolism.
• Inability to comply: Individuals unable or unwilling to follow study procedures, including continuous glucose monitoring and standardized test meals.

Cohort 2: Participants with Type 2 Diabetes Mellitus

Men and women aged 40-75 years. Body mass index (BMI) < 31 kg/m². Fasting plasma glucose > 125 mg/dL. HbA1c < 8.5%. Diagnosis of type 2 diabetes mellitus (T2DM) for at least 1 year before enrolment.

Stable treatment with hypoglycaemic, lipid-lowering, and/or antihypertensive medications for at least 3 months prior to enrolment.

Most participants will be recruited from the Diabetes Clinic of the 1st Propaedeutic Department of Internal Medicine, Laiko General Hospital.

Exclusion criteria

Endocrine, cardiovascular, pulmonary, renal, or gastrointestinal disorders that could affect study outcomes.

Sensitivity, intolerance, or allergy to any ingredients of the study breads. Pregnancy or breastfeeding. Eating disorders. Use of medications or dietary supplements considered incompatible with the study protocol.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Conventional White Bread exclusively prepared with 100% White flour; Study participants will consume a single serving of refined white wheat bread prepared from finely milled flour, providing 50 g of available carbohydrate, and served as a control test meal under controlled conditions.	Dietary supplement: Conventional white wheat bread; Conventional white wheat bread providing 50 g of available carbohydrate
Active Comparator: Wheat bread in which 30% of white flour is substituted with finely milled chickpea flour; Study Participants will consume a single serving of wheat bread in which 30% of finely milled wheat flour is replaced with finely milled chickpea flour, providing 50 g of available carbohydrate, served as a test meal under controlled conditions.	Dietary supplement: Wheat bread with 30% finely milled chickpea flour; Wheat bread formulated by replacing 30% of refined wheat flour with finely milled chickpea flour, providing 50 g of available carbohydrates
Active Comparator: Wheat bread in which 30% of white flour is substituted with larger particle size chickpea flour; Study Participants will consume a single serving of wheat bread in which 30% of finely milled wheat flour is replaced with larger particle size chickpea flour providing 50 g of available carbohydrate, served as a test meal under controlled conditions.	Dietary supplement: Wheat bread with 30% coarse chickpea flour; Wheat bread formulated by replacing 30% of refined wheat flour with coarse chickpea flour, providing 50 g of available carbohydrate.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postprandial incremental blood glucose area under the curve (iAUC₀-₁₈₀ min), measured by continuous glucose monitoring, after consumption of the bread enriched with 30% larger particle size compared with white wheat bread.	For the study in healthy subjects a sample size of 20 adults is needed, based on a power calculation with an α of 0.05 and power of 0.80 to detect a between white wheat bread difference of 20% in postprandial glycemia. For the study in diabetic patients a sample size of 14 adults is needed, based on a power calculation with an α of 0.05 and power of 0.80 to detect a between white wheat bread difference of 30% in postprandial glycemia.	0-180 minutes postprandially.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Postprandial incremental blood glucose area under the curve (iAUC₀-₁₈₀ min), measured by continuous glucose monitoring, after consumption of bread enriched with 30% chickpea flour compared with white wheat bread.	Postprandial blood glycemic response in healthy individuals, assessed by the incremental area under the glucose curve (iAUC₀-₁₈₀ min) using continuous glucose monitoring, following consumption of bread enriched with with 30% chickpea flour compared with white wheat bread.	0-180 minutes postprandially
Postprandial incremental blood glucose area under the curve (iAUC₀-₁₈₀ min), measured by continuous glucose monitoring, after consumption of the bread enriched with 30% larger particle size compared with bread enriched with 30% refined chickpea flour	Postprandial blood glycaemic response in healthy individuals, as assessed by the incremental area under the glucose curve (iAUC₀-₁₈₀ min) measured by continuous glucose monitoring following consumption of bread enriched with 30% larger particle size chickpeas compared with bread enriched with 30% refined chickpea flour. Glucose concentrations will be recorded continuously, and iAUC will be calculated over the 0-180 min postprandial period using the trapezoidal method, with baseline glucose defined as the mean glucose concentration during the 15 min prior to bread consumption.	0-180 mins

Collaborators and Investigators

• Sponsor: Harokopio University
• Collaborators: National and Kapodistrian University of Athens

Publications and helpful links

General Publications

• Kanata MC, Yanni AE, Koliaki C, Anastasiou IA, Tentolouris N, Karathanos VT. Impact of flour particle size and origin on the bread structure and the postprandial glycemic, insulinemic and appetite responses in healthy adults. Food Funct. 2025 Jun 3;16(11):4548-4561. doi: 10.1039/d5fo00348b.

Study record dates

Study Major Dates

• Study Start (Actual): September 29, 2025
• Primary Completion (Estimated): September 30, 2026
• Study Completion (Estimated): November 30, 2026

Study Registration Dates

• First Submitted: July 15, 2026
• First Submitted That Met QC Criteria: July 15, 2026
• First Posted (Actual): July 21, 2026

Study Record Updates

• Last Update Posted (Actual): July 21, 2026
• Last Update Submitted That Met QC Criteria: July 15, 2026
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: T2DM; Continuous glucose monitoring; postprandial glycemic response; particle size; flour milling; legume seeds; Subjective appetite sensations
• Additional Relevant MeSH Terms: Endocrine System Diseases; Metabolic Diseases; Glucose Metabolism Disorders; Diabetes Mellitus; Nutritional and Metabolic Diseases; Diabetes Mellitus, Type 2
• Other Study ID Numbers: Γ-2941/02-07-2025

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: There are no plans to share individual participant data collected during this study.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No