Saliva Insulin Responses to a Standardized Meal Tolerance Test in Humans

Recent evidence suggests that hyperinsulinemia (i.e., elevated insulin levels) is the primary causative factor in obesity. Insulin promotes fat storage and prevents fat breakdown, suggesting that weight loss would be optimized if insulin levels are managed and kept low. Understanding how different foods impact insulin levels could therefore aid in personalized weight loss (or weight maintenance) advice. It has been shown that salivary insulin can track plasma insulin following different meals and can delineate between lean and obese people. Thus, it was suggested that salivary insulin could be a potential surrogate for plasma insulin. The purpose of this study is to measure fasting saliva insulin, and salivary insulin responses to a standardized meal tolerance test in individuals with different body mass index (BMI).

Saliva samples and finger prick glucose will be collected after at least 4 hours of fasting and then at 60 and 90 minutes following ingestion of a standardized meal tolerance test.

The saliva insulin concentration measured by enzyme-linked immunosorbent assay - Area under the curve will be measured using the trapezoidal rule.

Salivary insulin at fasting (at least 4 hours of fasting), and at 60 and 90 minutes following mixed meal ingestion)

Finger prick glucose concentration measured by glucometer - Area under the curve will be measured using the trapezoidal rule.

Finger prick glucose will be measured at fasting (at least 4 hours of fasting), and at 60 and 90 minutes following mixed meal ingestion)

Inclusion Criteria: non-smoker have a body mass index greater than 18.5 kg/m2 have not been diagnosed with type 2 diabetes or other medical conditions affecting glucose or insulin levels Exclusion Criteria: You have been. diagnosed with diabetes (fasting blood sugar more than 7.0 mmol/l) or any other diagnosed chronic condition that may impact your glucose or insulin levels or the outcomes of this study. You take any medication which may affect your glucose and insulin level Unable to travel to make your testing appointments. Unable to consume the meal tolerance test drink/shake and/or provide finger stick glucose or saliva samples for the study.