Subjects enrolled into the study would be on stable Vagal Nerve Stimulation Blocker (VNB) intervention in excess of 12 months, having taken part in prior observational study examining the long-term effects of vagal inhibition. All subjects will be studied three times after using a mixed meal. Participants will be admitted to the Mayo Clinic Clinical Research Unit at 17.00 hours the evening before the study. Following ingestion of a standardized low calorie mixed meal (400 Kcal: 55% carbohydrate, 30% fat, and 15% protein) subjects will fast overnight. During the experiment subjects will undergo a mixed meal study as outlined below (Lead-in Mixed Meal 1). On the day after study, subjects will be randomized to one of 2 interventions: either discontinue use of the VNB or continue its use. Subjects will then be restudied (Mixed Meal 2) the day after admission to the Clinical Research Unit at 17.00 hours on the 13th day after randomization. To determine the metabolic effects, if any, of starting VNB therapy, on the day after study, VNB use will be resumed or discontinued depending on prior activation or inactivation. Subjects will then be restudied (Mixed Meal 3) the day after admission to the Clinical Research Unit at 17.00 hours on the 13th day after completion of Mixed Meal 2. Following completion of the study, VNB use will be resumed in all subjects.