Table 1.
Summary of the study schedule for enrolment, intervention and assessment.
| Assessments | Screening & Enrollment | Visit 1 |
Visit 2 |
Visit 3 |
Visit 4 |
|---|---|---|---|---|---|
| Day in study | 1 | 28 | 42 | 84 | |
| Week in study | −2 | 1–4 | 5,6 | 7–10 | 11,12 |
| General information form | ✓ | ||||
| Informed consent | ✓ | ✓ | |||
| Medical history | ✓ | ✓ | |||
| Weight | ✓ | ✓ | ✓ | ✓ | ✓ |
| Non-nutritive sweetener supplementation 1 | ✓ | ✓ | |||
| Blood draw 2 (1.5 mL) session | ✓ | ✓ | ✓ | ✓ | |
| Stool sample collection | ✓ | ✓ | ✓ | ✓ | |
| Laboratory measurements in plasma: glucose, insulin, glucagon, GLP-1, leptin |
✓ | ✓ | ✓ | ✓ | |
| Laboratory measurements in stool: fecal microbiome, fecal short-chain fatty acids (SCFA) |
✓ | ✓ | ✓ | ✓ | |
| Oral glucose tolerance test (OGTT) 3 | ✓ | ✓ | ✓ | ||
| Fasting blood glucose (FBG) test 4 | ✓ | ✓ | ✓ | ✓ | ✓ |
| Visual analogue scales (taste panel) 5 | ✓ | ✓ | ✓ | ✓ | |
| Diet history questionnaire | ✓ | ||||
| Food diary 6 | ✓ | ✓ | ✓ | ✓ | |
| Adverse event log | ✓ | ✓ | ✓ | ✓ |
1 This will be either aspartame or sucralose; visits to collect the supply will vary. 2 There will be five blood draws after the visits, and they will be conducted at the Richardson Centre for Functional Foods and Nutraceuticals (RCFFN). 3 OGTT will involve drinking a sweet liquid containing 75 g of glucose. 4 FBG will be conducted after a 10–12 h fast. 5 This test is to measure the participants’ tolerance to the sweetener mixed into beverages. 6 Food diaries documenting 2 weekdays and 1 weekend day.