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Keeping a Food Diary App: How to Do It

Jonathan Schäfer Last reviewed June 18, 2026 5 min read
Keeping a food diary on a smartphone
Quick answer

A food diary makes your eating visible — and this kind of self-monitoring is reliably linked to better weight-loss results. An app makes it easier than paper: meals can be logged in seconds by search, barcode or photo. Free entry options exist with Yazio and MyFitnessPal, but more important than the app is that you keep at it consistently.

What does a food diary do for you?

A food diary makes you aware of what and how much you actually eat — often more than you carry in your head. This self-monitoring is one of the best-supported behavioral factors in weight loss: a systematic review by Burke and colleagues (2011) found that consistent food logging is associated with markedly greater weight loss. The effect comes not from the diary itself, but from the attention it creates.

Paper or app?

Both work — but an app takes the math off your hands. Instead of looking up calories and macros yourself, you pick the food from a database, scan the barcode or photograph the plate. The app sums everything automatically and shows daily totals and trends. That lowers the effort per meal — and low effort is the single biggest reason people stick with it long term.

The best free food diary apps

For getting started, the free versions of established apps are enough. Yazio offers a free food diary with calorie logging (with ads). MyFitnessPal has the largest food database, though the free version lacks the barcode scanner. There are also dedicated diary apps such as iEatBetter or Eatrack. An honest note: "free" almost everywhere means comfort features sit in a subscription — but the free tier is usually enough for plain logging. For a detailed comparison, see our piece on the best calorie counting apps.

How do I keep a food diary on my phone?

In three steps: first, set up the app and define your daily goal (or have it calculated). Second, log each meal right away — fastest by barcode for packaged products, by photo for home-cooked food, by search for the rest. Third, keep the effort per meal low — the faster the logging by photo, barcode or chat, the more likely you are to stick with it. The key tip: log roughly and continuously rather than perfectly for just three days.

Mind your privacy: a food diary holds sensitive health data. Look for apps with GDPR-compliant processing and, ideally, servers in the EU — especially if you also store weight and photos.

GymLog AI — the diary that thinks along

GymLog AI turns the food diary into a chat: you type or photograph what you eat, the AI recognizes it and logs it — and an AI coach tells you how you stand relative to your goal. Weight is shown as a trend, not as daily fluctuation. The app is pre-launch and available via the waitlist; processing is GDPR-compliant.

Keep your food diary by chat with GymLog AI

Type or snap instead of filling in forms — the AI logs it, you keep the overview. Sign up now:

Join the waitlist

Sources

  1. Burke, L. E., Wang, J., Sevick, M. A. (2011). Self-monitoring in weight loss: a systematic review of the literature. Journal of the American Dietetic Association, 111(1). PubMed
This content is for general information and is not a substitute for medical or nutritional advice. App features reflect June 2026 and may change.