Photo food analysis: what it estimates and how to read it
Photo analysis turns a picture of a plate into a draft diary entry. It is fast, and it is an estimate. This page explains what the estimate contains, how a wrong portion changes it, and how to get better photos.
Updated September 2026 · How Mealyno builds its plans
What you get from a photo
- The foods the AI model recognises on the plate.
- A portion estimate for each food.
- Calories, protein, carbs and fat for the meal, plus fiber, sugar and sodium where available.
- A confidence score that tells you how sure the estimate is.
- A one-tap save to the diary, after you have confirmed or edited it.
The analysis uses Google Gemini Vision. Accuracy depends on lighting, portion visibility and how many ingredients are hidden.
A worked example: how a portion error changes the result
Take the meal Grilled Chicken and Quinoa Salad from our plan data: 420 g, 450 kcal and 42 g of protein. If the camera judges the portion 20% too small or too large, the numbers move in proportion.
| Grilled Chicken and Quinoa Salad | Portion | kcal | Protein |
|---|---|---|---|
| Portion judged 20% too small | 336 g | 360 | 33.6 g |
| Plan value | 420 g | 450 | 42 g |
| Portion judged 20% too large | 504 g | 540 | 50.4 g |
A 20% portion error moves this meal by 90 kcal and 8 g of protein. Over a day of four meals with errors in random directions, most of that averages out. Errors that all lean the same way do not, which is why the confidence score and your own edits matter.
How to get a better estimate
- Shoot in even light and show the whole plate.
- Keep major ingredients visible. Sauces and lids hide calories.
- Use barcode scan for packaged food. It reads label data instead of estimating.
- Save the meals you repeat as recipes. A checked entry beats a fresh estimate.
Which way to log: photo, barcode or typing
| Method | Best for | Main limit |
|---|---|---|
| Photo analysis | Plated and home-cooked meals | Portion size is judged by eye |
| Barcode scan | Packaged foods with a label | Only works for products in the database |
| Search or type | Meals you already know | Depends on your own portion estimate |
| Saved recipe | Meals you cook often | Needs one careful entry first |
When to trust it and when to edit
A photo estimate is good enough to tell you whether a meal was light on protein or heavy on fat. It is a weaker tool for deciding whether a meal was 520 or 580 kcal. Use it to log consistently, and edit any entry where you know the portion or the recipe.
Logging every meal roughly is usually more informative than logging some meals precisely, because the weekly pattern is what you read.
Limits worth knowing
- Mixed dishes such as stews, curries and bowls hide ingredients, so the estimate is wider.
- Drinks with sugar or milk are easy to miss in a photo. Log them by hand.
- Very small portions and garnishes are below what a photo can resolve.
- The estimate is not a laboratory measurement, and Mealyno does not present it as one.
See more
General information for healthy adults, not medical advice. Ask your doctor or a registered dietitian what is right for you.
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