Overnight Fasting After Completion of Therapy

The purpose of this study is to test whether regular not eating for at least 12 hours
("overnight fasting") can improve blood sugar and the health of the GI tract.

There are 2 parts to this study: Part 1 will last for 1-2 weeks and will determine whether
the patient can participate in Part 2. If they complete Part 1 they are eligible to
participate in Part 2, they will sign a separate consent form for Part 2. Part 2 of this
study will last 6 months.

Interim 1 lasts 14 days and begins 10-17 days before Study Visit 1. During Interim 1,
participants will complete 1-2 phone calls with study staff. During these calls, 24-hour food
recalls will be performed. Staff will use the NCI supported 24-hour recall instrument
(Appendix C) to facilitate the recall and enter dietary intake and timing of eating. Nightly
fasting duration will be estimated from the 24-hour diet recall by calculating the elapsed
hours between the last eating episode at night and the first eating episode the following
day. Participants will also be reminded about the fecal collection during these phone calls.

During Interim 2, participants will complete one to three phone calls with study staff
trained in motivational interviewing. These calls will be used to reinforce the prolonged
overnight fasting instructions, identify barriers to prolonged overnight fasting, and support
successes where they have occurred. Participants will also be prompted to send SMS text
messages via the MSK Information Technology secure text messaging system (currently used in
the clinical setting for wait time notification).