This study is being done to determine whether hormones will be secreted by the taste cells located in the taste buds in response to tasting food. The study will compare responses of these hormones in participants who are healthy and normal weight, healthy and overweight, or have pre-diabetes or type 2 diabetes and overweight.
Interested individuals will be scheduled for a screening visit, for which they will have to fast for at least 8 hours overnight. This visit will include medical history, physical examination, laboratory tests, and a 75-gram oral glucose tolerance test (OGTT).
Participants who meet the inclusion criteria will return for seven more study visits. If the participants have type 2 diabetes and are taking oral diabetic medications, they will need to stop taking the medications 5 days (3 days if they are taking metformin) prior to the study visit. They will need to check their fasting finger-stick blood glucose using their glucose meter every morning. If the glucose value is greater than 240, they will not be eligible for the study.
During the first study visit, the participants will be randomly assigned to one of seven groups:
- actual feeding (AF) with peanut butter sandwich
- modified sham feeding (MSF) with peanut butter sandwich
- MSF with chewing and spitting Parafilm® M
- MSF with swishing and spitting of 900 mg of sucralose solution
- AF with peanut butter sandwich with sucralose added to the peanut butter
- AF feeding with pork rinds (1 oz or 28 grams)
- AF feeding with pork rinds (2 oz or 56 grams)
Blood samples will be taken through an intravenous catheter every 1-minute for 40 minutes prior to the meal and then every minute for 40 minutes at the first bite of the meal. From 40 minutes to 60 minutes after the first bite, samples will be taken every 2 minutes, and from 60 to 180 minutes, samples will be taken every 15 minutes. A total of 99 blood samples will be taken. After each of the study visits, participants will be evaluated for the need for iron supplementation.
The participant will return for each of the subsequent visits at least 6 weeks after the previous visit. The same procedures as described in study visit 1 will be done except for the intervention, which is randomized. A hematocrit will be done to assure that it is within normal limits. If not, iron supplement Ferrous Sulfate 325 mg orally once daily will be given to the participant, and they will be rescheduled for the next visit in 4-6 weeks.
Purpose
