Influence of Resistant Starch Intake in Potatoes on Blood Glucose and Satiety Responses in Overweight Females

Influence of Resistant Starch Intake in Potatoes on Blood Glucose and Satiety Responses in Overweight Females

Influence of Resistant Starch in Baked and Boiled Potatoes on Glycemic and Satiety Responses in Overweight Females

Resistant starch (RS) is a type of fiber that has unique digestive properties that can impact overall health including glucose homeostasis and satiety. RS found in potatoes can be increased by using certain cooking methods and serving temperatures. The purpose of this trial will compare the acute glycemic and satiety responses after consuming potatoes differing in RS content that are 1) baked then chilled or 2) boiled and consumed hot in overweight females on two separate occasions.

Potatoes are a low-cost, nutrient-dense dietary staple in the U.S. rich in complex carbohydrates, potassium, magnesium, and fiber, but low in fat and sodium. Starch is the main complex carbohydrate found in potatoes that yields glucose to contribute to overall energy needs. Another type of starch found in potatoes is resistant to amylase hydrolysis in the small intestine which is resistant starch (RS). Trials using RS as a functional ingredient (~15-30 g/day) in healthy and overweight adults resulted in improvements in postprandial glucose, insulin sensitivity, satiety hormone response, and subjective satiety. Limited data exists using RS naturally found in commonly consumed foods, such as potatoes. Altering the cooking methods and serving temperatures of potatoes can influence the amount of RS to impact glucose, satiety hormone response, and subjective satiety. Using a cross-sectional, cross-over design, the aim of this study will determine how potatoes 1) baked and chilled or 2) boiled and consumed hot influence postprandial glycemic parameters, satiety hormones (glucagon-like peptide-1, peptide YY, and glucose-dependent insulinotropic polypeptide), subjective satiety, and subsequent energy intake in overweight females.

Participants will follow the same protocol for each arm with a minimum of 1-week wash-out period between arms. For each arm, fasting blood will be collected then 200 g of potato will be consumed. Postprandial blood will be collected 15, 30, 60, and 120 minutes. Subjective satiety will be assessed using Visual Analogue Scale three times, as well as 48-hour subsequent dietary intake.

Change in glucose and insulin concentrations collected 15, 30, 60, and 120 minutes following potato intake

Change in postprandial subjective satiety measured by Visual Analogue Scale (VAS) will be compared between interventions

Change in subsequent energy intake 48 hours following potato intake will be compared between interventions

Inclusion Criteria: Overweight and obese (BMI between 28 and 40 kg/m^2) Any race or ethnicity Exclusion Criteria: Diabetes or other metabolic disorder, cancer, or cardiovascular disease Smoking Pregnant or lactating More than 5% weight loss or gain over prior 6 months Following a special diet Sensitivity or aversion to potatoes