Enter your numbers
13 questions. Questions that only apply to some people appear once your earlier answers decide that they do.
From your health data
3 of these questions can be answered from lab results and device data you have already connected: Usual wake time, Usual bedtime, Usual training time. Connect them once in your member account and they arrive here pre-filled and labelled as coming from your health data — and you can always type over the value.
Set up health data in your member account
This public page never reads your health data. Pre-filling happens inside the signed-in app, which is a separate, access-controlled surface.
How this is calculated
Formula version lll-fasting-planner-1.0.0
The window opens a chronotype-dependent delay after wake time (early 0.5 h, intermediate 1 h, late 2 h) and closes 3 h before bed. If the requested window does not fit between those two constraints it is pulled earlier and shortened, and the tool says so. Training time is used only to place post-session protein within 2 h. Any declared contraindication stops the planner and returns no schedule.
What it cannot do
- A scheduling heuristic, not a validated protocol. The open-delay and pre-bed-gap rules are editorial.
- Where trials matched calorie intake, time-restricted eating did not beat ordinary calorie restriction.
- The favourable mechanistic results come from early windows; they do not transfer to late windows.
- Chronotype is self-reported here rather than measured by a validated questionnaire such as the MEQ or MCTQ.
- No account is taken of medication timing beyond the yes/no flag, of menstrual-cycle phase, or of caffeine.
Sources
- Sutton EF et al. Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss. Cell Metab 2018;27(6):1212-1221DOI 10.1016/j.cmet.2018.04.010 (opens in a new tab)PMID 29754952 (opens in a new tab)
- Jamshed H et al. Effectiveness of Early Time-Restricted Eating for Weight Loss, Fat Loss, and Cardiometabolic Health in Adults With Obesity. JAMA Intern Med 2022;182(9):953-962DOI 10.1001/jamainternmed.2022.3050 (opens in a new tab)PMID 35939311 (opens in a new tab)
- Lowe DA et al. Effects of Time-Restricted Eating on Weight Loss and Other Metabolic Parameters: The TREAT Randomized Clinical Trial. JAMA Intern Med 2020;180(11):1491-1499DOI 10.1001/jamainternmed.2020.4153 (opens in a new tab)PMID 32986097 (opens in a new tab)
- Liu D et al. Calorie Restriction with or without Time-Restricted Eating in Weight Loss. N Engl J Med 2022;386(16):1495-1504DOI 10.1056/NEJMoa2114833 (opens in a new tab)PMID 35443107 (opens in a new tab)
- Manoogian ENC et al. Time-restricted Eating for the Prevention and Management of Metabolic Diseases. Endocr Rev 2022;43(2):405-436DOI 10.1210/endrev/bnab027 (opens in a new tab)PMID 34550357 (opens in a new tab)
The formula version is pinned so that a result you saved or shared can be reproduced. When we change a coefficient, the version changes and old results stay attributed to the version that produced them.
Questions people ask
- Does fasting extend life?
- In humans, that has not been shown. Caloric restriction extends lifespan in several model organisms; the human trials measure surrogate markers over months and are mixed once energy intake is matched. This tool schedules a window; it does not promise an outcome.
- Why will it not plan a window for me?
- Because you ticked a contraindication — pregnancy or breastfeeding, type 1 diabetes, insulin or a sulfonylurea, a history of an eating disorder, being underweight, being under 18, or a medication that has to be taken with food. In those situations meal timing is a clinical decision, not a lifestyle one.