This study is a randomized, 3-arm, within subject cross-over trial allowing for three acute evaluations of 100% orange juice (250 g), 100% Orange Juice with enzyme-treated orange pomace fiber (157 g orange juice with 100 g orange pomace), and raw orange (227 g edible portion of navel orange) on glucose and insulin response in fifty-two healthy men and women aged 20-45 years.
A planned sample size of 52 will be enrolled into the study. This study will require one initial screening visit and 3 study visits. This study will take approximately 3-4 weeks per subject to complete.
The initial screening visit will take \~2 hours and provide subject with the informed consent document and determine subject eligibility through anthropometric measurements, body composition measurement, vital signs, fasting blood glucose test (finger prick), a vein access scale evaluation, online 24-hr diet recall, and completion of a survey relate to general eating, health, and exercise habits. For women, a pregnancy test will be conducted.
If willing and eligible to participate, subjects will be invited to participate in the study for 3 study days. Eligible subjects will be instructed to follow a relatively low polyphenolic diet for at least 1 week prior the beginning of the study and continue for the duration of the study.
Each Study Day visit will last about \~3 hours. The day before each of the 3 Study Day visits, subjects will be asked to consume the same dinner meal and record on a food record. At each Study Day visit, subjects will arrive at the clinic after fasting for 10 to 12 hours and in a well-hydrated and well-rested state.
Each study visit will require blood draws throughout the visit. After evaluation of subject's health status (via anthropometric, vital sign and blood glucose measurements and in-person interview), a Licensed health Care Professional will place a catheter in subject's arm for the purpose of multiple blood sample collections and take the initial blood draw in the fasting state. Subjects will be randomized to receive one of study products based on randomized treatment sequences for 3 study visits immediately after fasting blood draw.
Participants will come to the research site on 3 separate occasions separated by a washout period. On each occasion 2 fasting blood samples will be obtained at 5 min intervals (-5, 0 minute (min)). Subjects will then consume one of the 3 treatments. Further blood samples will be taken at 15, 25, 30, 35, 40, 45, 60, 75, 90, 105 and 120 min. Self-reported visual analog scales (VAS) will be used to measure subject hunger, fullness, desire to eat, and prospective food intake. After completion of all study procedures and data/sample collection for the day, the catheter will be removed and subjects will be evaluated for safety and/or discomfort/symptoms before leaving the study site. They will be given a take-home snack and given written instructions in preparation for the next visit. Study day visits will be scheduled at least 3 days apart but no more than 7 days.
