Location: Food Components and Health Laboratory
2013 Annual Report
Objective 2: Develop mathematical models relating blood glucose kinetics to whole body substrate oxidation. Sub-Objective 2.A: Determine the effect of physical activity, gender and age on postprandial and 24-h substrate oxidation and glycemic control. Sub-Objective 2.B: Develop predictive models and algorithms for existing ambulatory physiological monitoring systems to estimate real-time blood glucose and substrate oxidation based on continuous estimates of energy expenditure and duration and intensity of physical activity.
To investigate the role of whole grains in modulating blood glucose, a clinical intervention study was conducted and data analysis was completed. Consumption of whole grains are purported to support a healthy body weight, reduced incidence of diabetes, promote GI health, and reduce cardiovascular (CVD) risk. However, clinical studies supporting these benefits have been inconclusive. To investigate the role of whole grains in modulating glucose response, we conducted a double blind, crossover, randomized controlled trial with 3 treatments: whole grain oats, whole grain barley, and refined wheat flour (as a control). Volunteers were enrolled, and all 18 volunteers completed the intervention. After 3 days of controlled feeding, volunteers consumed a treatment diet that contained whole oats, whole barley or a refined wheat control diet. Blood samples were collected immediately before and for 7 hours after consuming the treatments. Whole grain compared to refined grain consumption did not change blood glucose or insulin. To investigate the role of whole grains in reducing CVD risk, we conducted a double blind, parallel arm, randomized controlled trial for 6 weeks with 3 treatments: whole grain oats, whole grain barley, and refined wheat flour (as a control) providing 4, 4, and 0.7 servings/day of whole grain at 1800 kcal, respectively. Volunteers were enrolled, and 68 completed the intervention. Volunteers consumed a controlled diet at weight maintenance for 6 weeks, with the base diet being the same across treatments, and cereal and crackers incorporated as treatment foods. After 6 weeks, we found improvement in cholesterol markers for coronary heart disease (LDL cholesterol-to-HDL cholesterol ratio) as well as improvement in blood pressure.
A study was completed with women and men examining the impact of intensity and duration of exercise on glucose regulation and substrate oxidation. Each participant completed 4-24h measures in a room calorimeter. Exercise treatments were either high intensity, short duration or low intensity and long duration. Data are currently being summarized and analyzed. A second study was initiated that examines the interaction of the consumption of meals containing predominantly fat, carbohydrate, or protein following either high intensity/short duration or low intensity/long duration exercise.