How to use a food and symptom diary to look for patterns

Before you start

Decide which feeling you want to watch. Feelments rates Digestion, Energy, Mood and others once a day, and details such as bloating after lunch go in the day's note. If your lips, face or throat swell or you find it hard to breathe after eating, call your local emergency number straight away. See a doctor rather than relying on a diary if you have blood in your stool, unexplained weight loss, or a condition you manage with your diet. If tracking what you eat makes you anxious, or you have had an eating disorder, talk to your doctor or care team before keeping a detailed food diary. The examples on this page are fictional.

Step by step

1. 1.

   Choose one or two feelings, such as Digestion or Mood, and rate each once a day at about the same time, for example in the evening. Write what you noticed and when in the day's note, such as "bloated about an hour after lunch". The NHS notes that food intolerance symptoms usually start a few hours after eating, so a late dinner can show up in the next day's rating.

2. 2.

   Save each meal, snack and drink as its own entry, with the time if you know it. Put the ingredients that might matter in the detail, such as milk in coffee or the sauce on a dish. A dish name alone hides what was in it.

3. 3.

   Rate the feeling every day, including days you feel fine. A diary that only records bad days cannot show how often a food appeared without trouble.

4. 4.

   Note sleep, stress, exercise, alcohol and illness in the day's note, and anything else that changes how you feel regardless of food.

5. 5.

   Keep going for at least two weeks that include two weekends, so that workdays and days off are both represented.

6. 6.

   Then read it by date, using the same rule for days with and without the food: for example, whether that day's Digestion rating was worse than usual. Count the days the food appears, how many of them were rated worse, and how many days without it were rated worse. Read the following day's ratings and notes as a separate check, not as part of the count.

Why a food that appears before a bad day is not necessarily the cause

A food you eat often appears before many bad days simply because it appears before most days. Comparing those days with the days you ate it without trouble, and with the bad days that did not include it, keeps a common food from looking guilty.

Bloating, tiredness and low mood also follow short nights, stress and illness. Notes about those let you set aside days that have another explanation before you read the food entries.

Removing foods has its own risks. The NHS advises against cutting foods out of your diet without advice from a GP or a dietitian, because you can miss vitamins and minerals. The British Dietetic Association advises making one change at a time and keeping a food and symptom diary while you do, so you can see what helped.

• NHS: Food intolerance
• British Dietetic Association: Irritable bowel syndrome and diet

A worked example

Check the result

In Feelments, open Views and create a view with a Feelings card for the feeling, set to 30 days. If you save a food as its own entry, add a Records card for it too. A Records card counts entries of one item, so it shows the days you saved "coffee with milk", not every dish that contained milk; to count an ingredient across dishes, read the details in Timeline or in the CSV export. When Feelments compares days you logged an item with other days, it compares the same dates for both and waits until both sides have enough days before showing anything.

Questions and troubleshooting

What this does and does not tell you

A diary can show which foods and feelings appeared on the same dates. It cannot diagnose an intolerance or an allergy, show that a food caused a symptom, or tell you which foods to remove. Bring it to a doctor or dietitian if symptoms persist or affect your daily life.