Participants will be identified for inclusion by leaders of the GI Clinic after GI surgery has been scheduled. Upon consenting, participants will be instructed how to download and use the mobile phone application "My Plate Calorie Counter".

My Plate Calorie Tracker is a user-friendly weight management, calorie record application, available for smart phone devices. Users have the option to input items manually (i.e., calories, carbohydrates, fats, and proteins), select from a list of popular food items, or scan barcodes on the food packaging. In addition to food entries, users can also enter daily water intake and physical activities. Once an account is created, data entered into the mobile application can be sync'd to the "My Plate Calorie Tracker" website.

Usability of smart phone application will be captured by (1) number of days that entries have been made by the study participants and recorded as a percentage of the total number of days after discharge from the hospital (obtained from mobile application (2) number of meals recorded in the application per day (obtained from mobile application) and (3) Exit Questionnaire (6 questions of 12). The Exit Questionnaire includes a mixture of 5-point Likert-scale, yes or no, and open-ended items to assess usability. Questions on the 5 point scale use 1 as an indication of difficulty in using application and 5 would be ease of use.

Patient's acceptability of the mobile application to assist with postoperative nutrition goals will be captured by the Exit Questionnaire (6 questions of 12). The Exit Questionnaire includes a mixture of 5-point Likert-scale, yes or no, and open-ended items to assess acceptability. Questions on the 5 point scale use 1 as an indication of acceptability issues of the application and 5 would be acceptability.

Adherence to the participant's recommended nutritional plan will be calculated by participant's energy (caloric) intake over time, as recorded in the digital food diary, and compared to estimates of the optimum energy needs established by the dietician. Adherence will be reported as a percentage of estimated energy requirements.