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Food Symptom Diary: Free 14-Day Template and Guide

Short answer: A useful food symptom diary records what and when you ate, symptom type and severity, when symptoms began, and context such as sleep, stress, activity, caffeine, alcohol, and medication. Record close to the event, keep the format consistent for 14 days, and look for repeated associations—not a diagnosis from one meal.

A diary can help you and a qualified clinician see details that are hard to remember later. It is an observation tool: many factors can occur together, and a repeated pattern still does not prove that one food caused a symptom.

Safety first: Do not use this guide to test a food that has caused a serious or immediate reaction. Seek urgent medical help for breathing difficulty, swelling of the lips, mouth, tongue, or throat, fainting, or other signs of a severe allergic reaction. Do not remove major foods or food groups long term without guidance from a doctor or registered dietitian, because unnecessary restriction can create nutritional risk.

Download the free diary template

The CSV opens in Excel, Numbers, Google Sheets, and most spreadsheet apps. Delete the example row before you start.

Download the 14-day CSV template

What to record

FieldWhat to writeWhy it helps
Food and timeMeal, drink, ingredients, approximate portion, and timeCreates a sequence to compare with later symptoms
SymptomType, severity from 0–10, and onset timeMakes separate symptom episodes comparable
Daily contextSleep, stress, activity, caffeine, and alcoholSurfaces plausible non-food explanations
Other contextMedication, supplements, illness, menstrual cycle if relevant, and unusual eventsReduces false conclusions from a single variable

A practical 14-day workflow

  1. Days 1–4: observe your normal routine. Do not intentionally change several habits. Log during or soon after meals and again when a symptom occurs.
  2. Days 5–11: keep recording consistently. Review the diary for repeated timing and symptom patterns. If a clinician recommends testing one change, keep other routines as steady as practical.
  3. Days 12–14: summarize, do not self-diagnose. Mark repeated associations, possible alternative explanations, and questions to bring to a doctor or dietitian.

Reintroduction can be unsafe for suspected allergies and is not appropriate for every condition. The NHS advises speaking with a GP or dietitian before cutting foods from your diet, and a clinician should decide whether and how a food should be reintroduced.

How to review the diary without overclaiming

  1. Group entries by one symptom, such as bloating or headache, instead of combining every complaint.
  2. Compare onset timing. A same-day association and a next-day association are different observations.
  3. Look for repetition across separate days, then check whether sleep, stress, alcohol, activity, or illness changed too.
  4. Write the conclusion as a question: “Does X repeatedly precede Y?” rather than “X causes Y.”

Common diary mistakes

When to share the diary with a clinician

Bring the diary to a medical appointment when symptoms recur, affect daily life, follow weight loss, or you are considering a restrictive diet. A concise summary helps: list the symptom, the dates it appeared, the suspected exposure, timing, severity, and competing explanations.

Frequently asked questions

What should I record in a food symptom diary?

Record the meal or drink, ingredients and portion, time, symptom and severity, onset time, sleep, stress, activity, caffeine, alcohol, medications or supplements, and notes.

Can a food diary diagnose an intolerance or allergy?

No. It can organize observations and help a qualified clinician understand recurring patterns, but it cannot diagnose an intolerance, allergy, or another medical condition.

How long should I keep a food symptom diary?

Fourteen days is a practical starting period for consistent observation. A clinician may recommend a different duration based on your symptoms and circumstances.

Sources and review notes

This guide was checked on August 30, 2026 against the NHS food intolerance guidance and the American Academy of Allergy, Asthma & Immunology guidance on elimination-diet risks. It provides general educational information and does not replace medical care.

Prefer a guided digital log? Burn is a self-observation tool for focused experiments; it does not diagnose medical conditions.

Use Burn on Android