Authors: Spencer Hawes, Katya Hulse, McKay Knowlton, Landon Deru, Bruce Bailey
Mentors: Bruce Bailey
Insitution: Brigham Young University
The aim of this study is to understand how the macronutrient composition of the fast-initiating meal influences glucose regulating hormones in older, sedentary, and abdominally obese adults. Insulin, amylin, and glucagon were measured immediately before and after a 24-hour fast, as well as 48 hours after fast initiation. Understanding these outcomes will inform fasting protocols such as time restricted eating and alternate day fasting, which offer potential long-term health benefits. 16 participants (7 male, 9 female) each completed two 24-hour fasts consuming only water. In random order, one fast began with a high carb shake and the other with a low carb shake of equal calories, volume and fiber density. After each fast, participants lived and ate normally and then returned 24 hours later. Venous blood draws were taken at hours 0, 1, 24, and 48 to monitor levels of insulin, amylin, and glucagon. There was a significant condition by time interaction for insulin (F = 4.08, P < 0.01), amylin (F = 3.34, P = 0.02) and glucagon (F = 7.93, P < 0.01). Insulin (P = 0.02) and amylin (P = 0.01) were higher and glucagon lower (P = 0.05) after consuming the high carbohydrate shake compared to the low carbohydrate shake. There was no difference, however, between conditions for insulin, glucagon or amylin at 0, 24 and 48 hours.