In one sentence
Four slider questions about how hungry and how full you feel, and one about how strongly thoughts of food intruded on the day: the subjective half of the energy record, which no scale or sensor can supply.
The four ratings
How hungry did you feel today; how full do you feel now; how strong was your desire to eat today; how much food do you think you could eat right now. VT asks them once a day, in the Daily Journal. Each is a 0-to-100 slider, the format appetite research has used for decades because it is quick, repeatable within a person and sensitive to a meal. VT combines the four into a satiety score, so that a day can be read on one number, and keeps the four answers underneath it.
Food noise
One question, 0 to 10: the intensity of unwanted or intrusive thoughts about eating today, from 0, no food noise, to 10, constant food thoughts. The phrase came into common use when people on appetite-reducing medicines described its absence; there is no established instrument for it yet, so VT asks plainly; its chart shades 0 to 4 and marks a higher day in amber. It is not a diagnosis of anything and VT never reads it as one.
Why it matters
The link between glucose and the next meal runs through appetite: in 1,070 adults, the glucose dip two to three hours after a meal went with more hunger, a shorter wait to the next meal and more eaten across the day (Wyatt 2021). Your appetite answers are how that finding is checked in your own record, meal by meal, and they are what the Weight Loss Plan reads when it looks for the meals that leave you hungry.
What moves it
The last meal's size, protein, fiber and timing; the dip after it; sleep, which moves hunger hormones; stress; the menstrual cycle; alcohol; training; and habit, which is the part food noise is for.
How to answer well
Quickly, at the same points in the day, without reasoning about what the answer should be; the first number that comes to mind is the one the scale was built for. Answer on days you feel fine as well, so the series has a baseline.
How Vitality Tracker uses it
Stored as the four responses and the satiety score, and the food-noise rating, per day; shown against the meal library's dip-after figures and on the Weight Loss Plan; nothing scores them and no engine reads them. Eir reads them when you ask why you were hungry.
How far to trust the number
Self-reported, and meant for within-person comparison; a 70 today against a 40 yesterday is a real difference in your experience.
Sources
- Wyatt P, et al. Postprandial glycaemic dips predict appetite and energy intake in healthy individuals. Nat Metab 2021;3:523–9. doi:10.1038/s42255-021-00383-x
- Vitality Tracker, What VT measures (catalogue of 15 October 2026).