Quick answer: A useful food and symptom diary records four things for every day: what you ate and drank (with rough amounts and main ingredients), when you ate it, any symptoms with a start time and a 0–10 severity, and context such as sleep, stress, your cycle, medicines and bowel movements. Below is a filled-in 7-day example and a five-step method for reading it. A diary shows patterns worth testing, not proof.
Most food diary templates are blank grids. Most "example" pages show one tidy line: "Lunch: sandwich. Symptoms: none." That doesn't help you on day nine, when you have pages of entries and still can't see what's going on.
This page fills in a whole week the way a real person might, mess included. Then it shows how to read it: which entries matter, which are noise, and what to test next. If you want a blank printable to start with, grab the one on our food and symptom diary page.
Key takeaways
- Log ingredients and rough amounts, not just meal names. "Stir-fry" hides onion, garlic, soy sauce and wheat.
- Write down the time a symptom started, not the time you noticed it was bad. Timing is how you link symptoms to meals.
- Many food-related gut symptoms show up hours later, and some reflect the previous day's food [1][3].
- Record context (sleep, stress, period, alcohol, medicines). It explains a lot of "random" bad days [7][8].
- One week gives you hypotheses. Two to four weeks gives you something worth showing a clinician [2].
What should a food and symptom diary include?
A food and symptom diary is a time-stamped record of what you eat and drink alongside the symptoms you notice, so that you (or your doctor or dietitian) can look for patterns. The NHS lists keeping one as part of how food intolerance is worked out, usually alongside a dietitian [1].
The trick is recording enough detail to be useful without making it a second job. These are the fields that earn their place:
| Field | What to write | Why it matters |
|---|---|---|
| Time | Clock time for every meal, snack and drink | Lets you count hours between a food and a symptom |
| Food and drink | Main ingredients and rough amount ("2 slices wheat toast, butter"; "large latte, whole milk") | Many reactions depend on the dose and the ingredient, not the dish name |
| Symptom | Type (bloating, cramps, gas, urgency, heartburn), start time, severity 0–10, how long it lasted | Separates a 2/10 twinge from a 7/10 evening |
| Bowel movements | Time and Bristol stool type (1–7) | Stool form is a rough guide to how fast things are moving [6] |
| Context | Hours slept, stress 1–5, period day, alcohol, exercise, new medicines or supplements | These can trigger or worsen gut symptoms on their own |
| Notes | Eating out, eating fast, very large meal, ate late | Restaurant meals and big portions often explain a pattern |
You don't need calories, grams of fiber or a nutrition database. Rough amounts ("half a plate", "a handful") are enough. If heartburn is your main symptom, add meal size and the time you lay down; our food diary for acid reflux explains why.
A filled-in food and symptom diary example
Here is an illustrative week for a fictional person, "Sam", who gets bloated and has loose stools a few times a week and suspects coffee. This is illustrative data, not a real patient. Symptom severity is 0–10; stool is Bristol type.
| Day | Meals and drinks (time) | Symptoms (start time, severity) | Bowel movements | Context |
|---|---|---|---|---|
| Mon | 7:30 oatmeal, blueberries, coffee with oat milk · 12:30 turkey sandwich on wheat bread, apple · 19:00 chicken stir-fry with onion, garlic, soy sauce, rice | 22:30 bloating 4/10 | Tue 7:15 type 5 | Slept 6 h; stress 3/5 (deadline) |
| Tue | 7:30 2 eggs, wheat toast, coffee · 12:30 leftover stir-fry · 18:30 salmon, potatoes, green beans | 16:00 bloating 6/10, gas | Wed 7:00 type 6; 11:00 type 5 | Slept 6.5 h; stress 4/5 |
| Wed | 7:30 oatmeal, coffee · 12:30 large salad with chickpeas, feta · 19:00 pasta with garlicky tomato sauce | 21:30 bloating 5/10 | Thu 7:10 type 5 | Slept 7 h; stress 2/5 |
| Thu | No coffee (ran out) · 8:00 yogurt, granola · 12:30 turkey sandwich, apple · 19:00 burrito bowl with black beans, onion, salsa | 14:00 cramps 3/10; 23:00 bloating 6/10 | Fri 6:45 type 6 | Period day 1; slept 7 h |
| Fri | 7:30 eggs, coffee · 12:30 rice bowl with chicken, carrots · 19:30 2 slices pizza, 2 beers (restaurant) | 9:00 cramps 2/10; 23:30 bloating 4/10 | Sat 8:30 type 4 | Period day 2; ate late |
| Sat | 8:30 pancakes, 2 coffees · 13:00 grilled chicken, potatoes, zucchini · 19:30 steak, rice, spinach | None | Sun 8:00 type 4 | Slept 8.5 h; stress 1/5 |
| Sun | 9:00 eggs, sourdough, coffee · 13:00 leftover chicken and rice · 19:00 homemade lentil curry with onion and garlic | 22:00 bloating 5/10 | Mon 7:30 type 6 | Slept 8 h; stress 2/5 |
How do you read a food diary?
Read a food diary by working backward from each symptom, looking across a window of hours (and the day before), then checking which suspects show up repeatedly and which bad days have another explanation. Here's that process on Sam's week.
Step 1: Mark every symptom and look back, not just at the last meal. FODMAP-related symptoms usually take at least about 4 hours to appear, because the food has to reach the lower gut first [3]. Symptoms within minutes of eating are more likely the gastrocolic reflex, the normal "eating wakes up the bowel" response, which can be exaggerated in IBS [3]. So for Sam's 22:30 Monday bloating, dinner at 19:00 and lunch at 12:30 are both in play.
Step 2: List the suspects that appear before most symptom episodes. Before five of Sam's six bloating evenings there was a meal heavy in onion, garlic, wheat or beans: the stir-fry (twice), the chickpea salad plus garlicky pasta, the bean burrito bowl and the lentil curry. Monash lists onion, garlic and wheat as high in fructans and most legumes as high in GOS, two types of FODMAP [4].
Step 3: Look for days that break the pattern. These are the most useful entries in any diary.
- Coffee appeared every day except Thursday, yet Thursday was one of the worst days. Saturday had two coffees and no symptoms. Coffee looks like a weak suspect for this pattern.
- Saturday had no onion, garlic, wheat-heavy meal or beans, and no symptoms.
Step 4: Check the confounders. Tuesday's symptoms came with poor sleep and high stress; in one small study of women with IBS, poorer sleep predicted more abdominal pain the next day [7]. Thursday and Friday's cramps lined up with the first days of Sam's period, when many people notice more gut symptoms [8]. Friday's late restaurant pizza and beer bundles several changes at once (wheat, likely garlic, alcohol, a late meal), so it can't point at any single one.
Step 5: Turn it into a hypothesis and a next step. Here's what this one week supports:
| Hypothesis | Evidence for | Evidence against or confounders | Sensible next step |
|---|---|---|---|
| Onion, garlic, wheat and legumes (fructans and GOS) are linked to evening bloating and looser next-day stools | 5 of 6 bloating evenings followed these meals; symptom-free Saturday had none | Several of these foods often appear together, so they can't be separated yet; Tuesday also had stress and poor sleep | Keep logging 1–3 more weeks, then talk to a doctor or dietitian about a structured test |
| Larger "stacked" meals matter more than single ingredients | Worst days combined several (salad with chickpeas, then garlic pasta) | Portion sizes weren't recorded precisely | Note portion size for a week; Monash notes that several small servings of FODMAP foods in one sitting can add up [5] |
| Coffee is the trigger | Coffee was drunk on most symptom days | Symptoms without coffee (Thu); two coffees and no symptoms (Sat) | Lower priority; recheck after more weeks |
| Period and stress amplify symptoms | Thu–Fri cramps; Tue stress | One week of data | Keep tracking cycle day and stress |
Notice what the table doesn't say: "Sam is intolerant to onions." One week shows an association. It can't prove cause, and it can't separate foods that always travel together. For more on that difference, see how to tell real patterns from coincidence.
What are the most common food diary mistakes?
The most common mistakes are blaming the last meal, logging dish names instead of ingredients, and only writing on bad days. Each one quietly ruins the pattern you're looking for.
- Last-meal bias. Symptoms can start a few hours after the food, and food intolerance symptoms can last hours or days [1]. Always look back at least through the previous day. Our guide to delayed food intolerance symptoms covers the timing windows.
- Meal names instead of ingredients. "Burrito bowl" tells you nothing. "Black beans, onion, salsa, rice" does.
- Only logging bad days. Good days are your comparison group. Without them you can't see that Saturday was symptom-free and onion-free.
- Changing everything at once. If you cut coffee, dairy and gluten on the same Monday and feel better, you've learned nothing about any one of them.
- Stopping too soon. IFFGD suggests keeping a daily diary for 2–4 weeks to see how diet, stress, sleep and exercise relate to symptoms [2]. One week rarely repeats each food often enough.
How long should you keep a food and symptom diary?
Plan on at least two weeks and ideally four. IFFGD's diary is designed for 2–4 weeks [2], which is long enough for most foods to appear several times and for a menstrual cycle, a stressful week and a relaxed week to show up. Our step-by-step guide on how to identify food triggers explains what to do once you have that data.
How to track this without burning out
Paper works. So does a notes app. What matters is logging at the time, because memory is bad at "what was in that sauce" and worse at "when did the bloating start."
A simple routine:
- Log each meal as you eat it (a photo is fine; add the main ingredients later the same day).
- Log symptoms when they start, with a 0–10 number.
- Log every bowel movement with its Bristol type.
- Add one line of context before bed: sleep, stress, period day, alcohol, anything unusual.
- Once a week, do the five-step read above.
For ongoing records, explore the Get Regular food and symptom tracker. Check the current workflow, privacy information and access before entering sensitive information. A recorded association is a question to investigate, not a confirmed trigger.
When to see a doctor
A diary is for everyday symptoms that come and go. Don't use it to wait out warning signs. See a doctor promptly if you notice [9]:
- Blood in your stool, or black, tarry stools
- Unintended weight loss
- Anemia (for example, found on a blood test, or unusual tiredness and breathlessness)
- Symptoms that wake you up at night, persistent fever, or severe or worsening pain
- A lasting change in your bowel habits, especially if it starts after age 50
- A family history of celiac disease, colon cancer or inflammatory bowel disease
If a food causes hives, swelling of the lips or throat, wheezing or trouble breathing, that's a possible allergy, not something to track. Get emergency help for breathing problems or throat swelling.
FAQ
What does a food diary look like? At minimum, it's a table with columns for time, food and drink, symptoms and notes. A better one adds bowel movements (Bristol type) and context like sleep, stress and cycle day, as in the example above.
How detailed does a food diary need to be? Detailed enough to name ingredients and rough amounts. You don't need to weigh food. "Large bowl pasta, garlic tomato sauce" is much more useful than "dinner", and much easier than grams.
Should I write down symptoms that seem unrelated to food? Yes. Write down headaches, poor sleep, period pain and stress too. They can explain "random" bad days and keep you from blaming an innocent food.
Can I keep a food diary on my phone? Yes. A notes app, a spreadsheet or a tracking app all work, as long as each entry has a time. Photos are a fast way to capture meals, though you may still need to note hidden ingredients like sauces and oils.
What if my food diary doesn't show any pattern? That's useful information too. It may mean food isn't the main driver, or that the pattern depends on amount or combination. Bring the diary to a doctor or dietitian rather than cutting foods at random.
Sources
- NHS. Food intolerance. https://www.nhs.uk/conditions/food-intolerance/
- IFFGD. Personal Daily Diary (IBS), publication #147. https://iffgd.org/resources/publication-library/personal-daily-diary-ibs/
- Collins L. Eating and IBS symptoms. Monash FODMAP blog, 2018. https://www.monashfodmap.com/blog/eating-and-ibs-symptoms/
- Monash FODMAP. High and low FODMAP foods. https://www.monashfodmap.com/about-fodmap-and-ibs/high-and-low-fodmap-foods/
- Monash FODMAP Team. FODMAP Stacking Explained, 2022. https://www.monashfodmap.com/blog/fodmap-stacking-explained/
- Lewis SJ, Heaton KW. Stool form scale as a useful guide to intestinal transit time. Scand J Gastroenterol. 1997. https://pubmed.ncbi.nlm.nih.gov/9299672/
- Buchanan DT, et al. Sleep measures predict next-day symptoms in women with irritable bowel syndrome. J Clin Sleep Med. 2014. https://pmc.ncbi.nlm.nih.gov/articles/PMC4153105/
- Heitkemper MM, Chang L. Do fluctuations in ovarian hormones affect gastrointestinal symptoms in women with irritable bowel syndrome? Gend Med. 2009. https://pmc.ncbi.nlm.nih.gov/articles/PMC3322543/
- NIDDK. Diagnosis of Irritable Bowel Syndrome. https://www.niddk.nih.gov/health-information/digestive-diseases/irritable-bowel-syndrome/diagnosis
This article is for general education and isn't medical advice. Get Regular is a tracking app — it doesn't diagnose or treat any condition. If you have red-flag symptoms or ongoing changes in your digestion, talk to a doctor.