This is a randomized, controlled, cross-over study on the effects of consumption of Deepure puerh tea extract (PTE) on glucose tolerance and metabolic markers.

The study will involve consuming three different doses: 1 gram, 1.5 grams, and 2 grams, and will be given in warm water, with a bland meal. The effects on glucose and insulin after consumption will be evaluated.The subjects will be randomly assigned to one of four groups with different sequences.

Inclusion Criteria:

• Men and women;
• Aged 18-70 years;
• BMI between 20-30;
• Fasting blood glucose at screening between 71-125 mg/dL. both inclusive.

Exclusion Criteria:

• Taking dietary supplements judged to interfere with the effects of Deepure on glucose metabolism (for example: cinnamon extract; chromium picolinate; mulberry extract; bitter melon extract, green tea extracts, black tea extracts, pu-erh tea);
• Participation in other clinical trials, involving an investigational product or lifestyle change, during the last month;
• Participation in another research study during this trial, involving an investigational product or lifestyle change; Taking prescription medication known to affect glucose metabolism;
• Taking over-the-counter medication known to affect glucose metabolism;
• Drinking 3 or more cups of tea daily;
• Unwilling to abstain from drinking tea for 24 hours before clinic visits; (if a person drinks tea within 24 hours of a clinic visit, the person's visit will be re-scheduled);
• Consuming 2 or more drinks of alcohol per day;
• Unwilling to abstain from drinking alcohol for 10 hours before clinic visits;
• Diagnosed with diabetes Type I; Taking medication for diabetes Type II;
• Diagnosed with the thyroid disorder Hashimoto's disease;
• Past major surgery to your stomach or intestines (minor surgery not a problem such as hernia repair, appendix removal, gallbladder removal);
• Currently taking cholesterol-lowering medication (for example: statins);
• Currently taking coumadin;
• Major trauma within the past 6 months;
• Major surgery within the past 6 months;
• Severe chronic infectious disease (such as HIV, chronic hepatitis);
• Active depression;
• Self-reported eating disorders;
• History of drug abuse during past two years;
• Currently going through intense stressful events or life changes;
• Women of child-bearing potential: Pregnant, breast-feeding, or trying to become pregnant;
• Women of child-bearing potential: Not using effective contraception;
• Food allergies or sensitivities to tea.