The Dose-response Effects of D-allulose (Psicose) With Sucrose Beverage on Glucose Tolerance and Insulin Level in Healthy Volunteers and Volunteers With Impaired Fasting Glucose

Objectives Primary objectives 1. To investigate the dose-response effects of D-allulose (psicose) with sucrose beverage on glucose tolerance 2. To investigate the dose-response effects of D-allulose (psicose) with sucrose beverage on insulin levels Subjects and methods Study product A. Sucrose 50 g B. Sucrose 50 g + D-allulose (psicose) 2.5 g C. Sucrose 50 g + D-allulose (psicose) 5 g D. Sucrose 50 g + D-allulose (psicose) 7.5 g E. Sucrose 50 g + D-allulose (psicose) 10 g Study plan Screening (visit 0) * Obtain inform consent * History taking for medical problems, smoking, alcoholic drinking, concurrent medication, contraception or menopausal status, weight history * Measure body weight, height and calculated BMI * Measure waist and hip circumference * Body composition measurement by bioelectrical impedance analysis (BIA) * Complete physical examination * Urine pregnancy test in all female of childbearing potential * Provide 24-hour food record * Ask to come back within 1 week Visit 1: (day 7 or 6-11 days) * Complete physical examination * Randomize subject to receive any 1 of 5 study products * Perform OSTT with that product * Return food record * Provide 24-hour food record * Adverse events evaluation * Ask to come back within 7 +/- 4 days Visit 2: (day 7 or 6-11 days from visit 1) * Complete physical examination * Randomize subject to receive any 1 of 4 study product which are left * Perform OSTT with that product * Return food record * Provide 24-hour food record * Adverse events evaluation * Ask to come back within 7 +/- 4 days Visit 3 (day 7 or 6-11 days from visit 2) * Complete physical examination * Randomize subject to receive any 1 of 3 study product which are left * Perform OSTT with that product * Return food record * Provide 24-hour food record * Adverse events evaluation * Ask to come back within 7 +/- 4 days Visit 4 (day 7 or 6-11 days from visit 3) * Complete physical examination * Randomize subject to receive any 1 of 2 study product which are left * Perform OSTT with that product * Return food record * Provide 24-hour food record * Adverse events evaluation * Ask to come back within 7 +/- 4 days Visit 5 (day 7 or 6-11 days from visit 4) * Complete physical examination * Perform OSTT with the product that is left * Return food record * Adverse events evaluation Adverse Event Assessment At each visit, participants will be asked an open question as if he/she has experienced any abnormal symptoms. Any symptom reported by the participants will be recorded as an adverse events with details of the event, its severity, start and stop dates, and relationship to study products. Gastrointestinal symptoms (heartburn, distension, nausea, vomiting, abdominal pain, flatulence, constipation and diarrhea) within 24 hours after OSTT will be asked and recorded as well. Withdrawal criteria 1. Those who are not able to complete 5 visits of OSTT within 8 weeks 2. Those who cannot provide 24-hour dietary record at each visit 3. Those who start any medication that might cause increasing in plasma glucose during participating in the study