Guides

Build a food-and-sleep history with Apple Watch or WHOOP

5 min read · Updated October 7, 2026

You already have sleep readings. You can remember last night’s dinner. What is harder is remembering both accurately across several weeks.

This guide helps you build that record. For 21 days, log your usual meals, keep your wearable routine consistent, and check that the two histories are available. You do not need to start a new diet, change your training, or buy Pro to take part in this logging activity.

Download the free one-page guide and 21-day checklist

The checklist is yours to keep. No email signup is needed to download it.

1. Connect the data you already collect

KeepEatClean’s food-and-wearable history is on iPhone. Apple Watch readings reach it through Apple Health; WHOOP uses a separate connection. A companion Watch app for quick meal logging has been submitted in version 1.22. See the Watch preview and current availability; iPhone is required for setup and meal estimates.

Apple Watch / Apple Health

  1. Check that a recent night of sleep appears in the Health app on your iPhone.
  2. Choose Apple Health in KeepEatClean’s setup and review the requested permissions. In the current app, the source controls are in Settings under Health source.
  3. Check that KeepEatClean shows a recent reading before you rely on it. If a reading is missing, first check the source app and your permissions.

WHOOP

  1. Confirm your recent sleep and recovery readings are available in WHOOP.
  2. Choose WHOOP in KeepEatClean’s setup or Health source settings, then complete the separate WHOOP authorization.
  3. Check that recent readings appear. Available measures depend on your connection and permissions; WHOOP does not supply Apple Health steps.

You can review the app’s Where your data comes from screen to understand the source of a reading. Screen wording may change with app updates. Read more about the WHOOP connection and the Privacy Policy.

2. Choose a question, then observe your usual routine

Use a concrete question that a history could help you explore. For example: How does my usual dinner timing line up with next-morning sleep?

Keep the question as a question. A single night does not establish a pattern, and logging for three weeks does not guarantee an answer. Other parts of your life and training can change at the same time.

3. Make the daily record useful

  • Log meals and meal times. Check photo estimates and edit the food or portion when needed. Estimates are not precise measurements.
  • Keep collecting wearable readings. Use the same source where practical, and check for missing nights. Leave missing values as gaps.
  • Tick the private checklist. A tick means you logged meals and have a wearable reading; it does not mean the app has found an insight.

If useful, keep a private note about an unusual training day, travel, or disrupted routine. It may help you interpret a comparison later. You do not need to send that note to anyone.

4. Review on day 21

Start with two simple checks: was the routine manageable, and is the record complete enough to keep using?

Then review whatever Food × Body currently shows. It examines usable paired food-and-health days and applies evidence checks before showing a supported finding. Twenty-one calendar days do not necessarily equal twenty-one usable paired days. Insufficient data or no clear pattern are legitimate results.

A finding is an association, not proof that a meal or habit caused a sleep or recovery outcome. This guide does not prescribe food, promise better recovery, or replace professional advice.

For running clubs, coaches and dietitians

You may share the linked guide, unchanged and with KeepEatClean credited, as an optional resource for adults who already use an iPhone and collect relevant wearable data. Participants can choose their own start date. They can stop at any time.

This is a personal logging activity, not a clinical study or nutrition program. It does not create a coaching relationship, promise a health outcome, or require the club to collect anyone’s food or health records. The guide is free; the app has a free tier and optional paid Pro. No special Pro grant is included.

If your group tries it and wants to give feedback, a short note about whether setup was clear and the routine manageable is enough. Please do not include health records, identifiable participant information, or screenshots of private readings. Email the founder.

Suggested invitation to members

Want to build a record of meals alongside your sleep readings? This optional 21-day guide from KeepEatClean explains how to log your usual meals and connect Apple Health or WHOOP. Use your own iPhone and existing wearable setup, keep the record private, and review how manageable the routine feels. No diet change, purchase, or result by day 21 is required or promised. Download the free guide below.

Download the printable guide · View KeepEatClean on the App Store

General information, not medical advice. If you have a medical condition, a sleep disorder or a history of disordered eating, talk to a clinician before changing how you eat.