 Glycogen storage disease GSD patients frequently experience periods of hypoglycemia, putting them at risk for several complications, such as hepatomegaly, adenomas, and cirrhosis. As of now, glycogen storage disease patients are limited to using finger stick glucose meters to monitor their glycemia at home. Diabetes Sentry, a non-invasive hypoglycemia detector designed like a watch, has been available for diabetic patients to non-invasively alert for hypoglycemia, but has never been tested in a GSD population. The investigators propose to test the accuracy of the Diabetes Sentry on patients with GSD types 0, I, III, VI, and IX, by measuring their metabolic markers every two hours, as well as whenever the device alerts for hypoglycemia. If accurate, it could be a useful tool for GSD patients in managing hypoglycemia, both clinically and at home. 