The primary aim of this study is to determine the effectiveness of durian on thermic effect of food (TEF), blood pressure, heart rate and postprandial glucose and lipid levels in young healthy men and women, compared to the ingestion of isocaloric banana.

Visit 1: Consenting and screening for study criteria. Visit 1 consists of consenting and screening session. Potential subjects will arrive at CNRC at 8h30 after 10-hour overnight fast (at least), only allowed access to water. A copy of written participant information sheet and informed consent form (ICF) will be given for them to read through carefully with needed time, and they may question for unclarity. Upon satisfaction, subjects must sign the ICF prior to the study procedures. After the consent, subjects will be screened for their eligibility with health screening questionnaire, and undergo anthropometric measurements (i.e. weight, height, waist circumference, and hip circumference). BMI will be calculated using formular weight divided by meter square (kg/m2). Blood pressure and heart rate readings will be taken. Body composition will be assessed using bioimpedance (BIA). Female subjects will be required to perform a β-HCG test using a urinary pregnancy test kit. Fasting glucose test will be performed through finger prick.

Visit 2 and 3: Intervention study (durian or banana will be assigned randomly) Visit 2 and visit 3 correspond to test session. Female subjects will be tested in the follicular phase of the menstrual cycle (the last menstrual cycle will be noted during screening and regular follow-up for the update). On each test day, subjects will arrive at CNRC at 8h30 after 10-hour overnight fast (at least), only water is allowed. They will undergo anthropometric measurements, and then instructed to lay comfortably on a bed in a suite (room temperature 22-24°C) for 45-minute of resting metabolic rate (RMR) measurement. Blood pressure, heart rate, fasting blood glucose, and fasting lipid will be performed before the meal test. At 9h30, subjects will be served 250g of durian or 417.6g of banana in a plate with 200 mL of water, and requested to consume the entire test meal within 10 min. Thermic effect of test meal will be performed after ingestion for 3 hours. Blood glucose fluctuation will be measured at 15 min, 30 min, 60 min, 90 min, 120 min, 180 min, and lipid fluctuation will be measured at 60 min, 120 min, and 180 min by finger prick. Blood pressure and heart rate readings will be taken at 30 min, 60 min, 120 min, 180 min.

Inclusion Criteria:

• BMI with the range of 18-25 kg/m2
• Aged between 21 and 40 year-old
• Chinese origin
• Non-diabetic, fasting blood glucose ≤ 5.6 mmol/L
• Blood pressure below 140/90 mmHg
• Pass the general health screening questionnaire
• Have a stable bodyweight (<5%) over the past 6 months
• Have no medical history
• Have ability to provide informed consent

Exclusion Criteria:

• Subjects who are smoker or currently on nicotine therapy
• Subjects who regularly consume alcohol (>1 unit per day)
• Subjects who are currently receiving therapy (e.g. insulin) or any medication/treatment (including supplements) that may affect glucose and lipid metabolism, energy metabolism or body composition.
• Subjects who are currently on steroids, protease inhibitors, or antipsychotic therapies
• Subjects who recently had a major medical or surgical event or will have one during the study period
• Subjects who have symptomatic Irritable Bowel Syndrome
• Subjects who have glucose-6-phosphate dehydrogenase (G6PD) deficiency
• Subjects who have active Tuberculosis (TB) or currently receiving treatment for TB
• Subjects who have chronic infection or is known to suffer from or has previously suffered from or is a carrier of Hepatitis B Virus (HBV), Hepatitis C Virus (HCV), Human Immunodeficiency Virus (HIV)
• Subjects who participated in drug trial within 3 months before the start of the study
• Subjects who have allergy or intolerant to durian or/and banana
• Subjects who are unwilling to consume durian or banana
• Subjects who are hemophobia, trypanophobia, or claustrophobia
• Subjects (females) who are pregnant (pregnancy test will be performed), lactating, or planning to become pregnant during the study period
• Subjects who do not have adequate fluency in the English language
• Subjects who are unable to understand the study procedures and to sign forms providing written informed consent to participate in the study
• Subjects who are a member of the research team or their immediate family members. Immediate family member is defined as a spouse, parent, child, or sibling, whether biological or legally adopted

Female subjects will be tested in the follicular phase of the menstrual cycle (the last menstrual cycle will be noted during screening and regular follow-up).

Access to and the key/password linking participant identifiable data to research data will be handed to a trusted third party (SIFBI HBRO) who is not part of the study team upon the end of data collection. All collected hardcopy data will be filed and stored in secure key-access drawers or in a key access room which will remain locked at all times. These keys are held by SIFBI HBRO and authorized staff at the centre and only study team members and authorized staff are allowed to draw the files. For electronic data, they will be stored in a secured computer that is password protected.