An app to scan your fridge and find a meal that fits your macros
Wondering what to cook tonight with what’s left in the fridge, without starting your calculations from scratch? A useful app needs to match the ingredients available to your remaining macros: the protein, carbohydrates and fat still planned for your day. A scan can suggest a meal idea, but it cannot measure portions exactly. Here’s how to go from a photo to dinner, then check what you actually eat.
A meal idea that takes your day into account
For this task, recognising foods is not enough. The app also needs to take account of what you have already eaten, rather than simply choosing a recipe based on the contents of your fridge.
Sthenia can scan up to three photos of your fridge to suggest a meal tailored to your remaining macros for the day. The suggestion is a starting point: it does not guarantee that the meal you prepare will match the target values exactly.
This is different from photographing a dish: the fridge scan helps you decide what to cook, while a photo of a dish is used to estimate the calories and macros in an already prepared meal. In both cases, an image is no substitute for checking ingredients and quantities. See Sthenia’s nutrition methodology for the limits of its calculations and estimates.
Before scanning: prepare useful information
A few checks can help you avoid starting with a misleading picture of your remaining intake or foods that are hard to identify.
Update your food diary. Check the meals, snacks and drinks you have already consumed. Forgetting to log a food can make it look as though you have more calories or macros left than you actually do.
Make the ingredients you want to use visible. Choose clear, well-lit photos rather than a cluttered view with food hidden behind packaging.
Identify unclear contents yourself. An opaque container or leftovers in a sauce need checking. Keep packaging within reach so you can check ingredients if necessary.
Check what you have outside the fridge too. Bread, tinned foods or starchy foods can complete your dinner, but do not assume the app knows about anything that is not in the photos.
Keep practical constraints in mind. A suggestion may look suitable on paper but not fit the time or equipment you have available. Choose a dish you can actually prepare tonight.
Example: turn cooked rice into dinner
An illustrative editorial example, not an observed Sthenia scan result.
Your fridge contains cooked rice, courgettes and eggs. One concrete idea would be fried rice with courgettes and eggs. That gives you a direction for dinner without having to build a recipe from scratch.
The next step is to check: compare the quantities you plan to cook with your remaining macros. Do not assume that the presence of eggs or rice alone makes the dish suitable for your day. The quantity of each ingredient and anything added during cooking matter too.
If you change the recipe, use its final ingredients for your tracking. Adding a sauce or replacing an ingredient changes the meal: the values in the original suggestion may no longer describe what you are going to eat.
What a photo cannot confirm
| What appears in the photo | What remains uncertain | What to check |
|---|---|---|
| An opened packet or partly used container | The quantity actually available | Check the contents and weigh the amount you use if you want to refine your tracking. |
| Cooked leftovers or a dish in sauce | Mixed ingredients and less visible additions | Check what went into it rather than relying only on its appearance. |
| A product with an unreadable label | Its ingredients and nutritional information | Read the packaging directly. |
| A selection of ingredients | The amount that will end up on your plate | Distinguish between what is available, what is cooked and what is eaten. |
A photo estimate is not an exact measurement of portions. Meal-plan calculations, manual tracking and photo estimates are separate processes: see [Sthenia’s nutrition methodology](https://sthenia.app/en/guides/how-sthenia-builds-and-checks-a-meal-plan) to understand their limits.
Log the meal you ate, not just the meal suggested
The scan answers the question, “What can I prepare?” The food diary answers a different question: “What did I actually eat?” This distinction matters as soon as you change a recipe or leave some of the dish uneaten.
For more consistent tracking, enter the ingredients and quantities you actually consumed. If you weigh a food, use a reference that matches its state, raw or cooked. Remember to include oils, sauces and side dishes added during preparation.
A kitchen scale can help you establish quantities more precisely, but it does not turn the entire calculation into a perfect measurement. If you do not know a quantity, remember that the total remains an estimate.
To explore this step further without confusing it with scanning, see the guide to free calorie and macro tracking.
A partial match with food reference data or an unresolved ingredient can reduce confidence in the estimate. Sthenia’s nutrition methodology explains these limitations.
Free tracking and scan access: check what is included
Sthenia’s food diary and manual calorie and macronutrient tracking are free and unlimited. Personalised weekly meal planning is part of the paid Pro offering, as explained in the feature overview.
Do not assume that free manual tracking means the fridge scan is included too. If this feature is the reason you are choosing the app, check its access conditions in the offer shown before subscribing.
Your needs are the deciding factor: logging a dinner you have already chosen and getting a suggestion from your fridge are two different uses.
References: [7]
Frequently asked
- Do I need to know my macros before using the fridge scan?
You do not need to memorise your targets. Sthenia estimates nutritional targets based on your profile, sport, training frequency and goal. These targets remain estimates, not a measurement of your metabolism. For a suggestion to take useful account of your remaining macros, your food diary also needs to reflect what you have consumed. The nutrition methodology explains these distinctions.
References: [7]
- Can I add foods from the cupboard to the meal?
Yes, you can complete your meal with foods you have available. However, do not assume the scan knows about ingredients that are not in the photos. If you add bread, a tinned food or another side dish, include it when tracking the final meal rather than keeping the suggestion’s estimate without checking it.
- What should I check if I have a food allergy?
Do not rely on the scan alone to decide whether a meal is suitable for a food allergy. The NHS recommends checking labels and menus carefully and not eating a food without first checking its ingredients. Keep this check separate from the recipe suggestion, particularly for sauces and cooked leftovers.
Sources
- [1]Review of the validity and feasibility of image-assisted methods for dietary assessment.
- [2]Feasibility of Reviewing Digital Food Images for Dietary Assessment among Nutrition Professionals.
- [3]Purchase to Plate - Documentation | Economic Research Service
- [4]Accuracy of food photographs for quantifying food servings in a lunch meal setting among Danish children and adults.
- [5]Portion size estimation in dietary assessment: a systematic review of existing tools, their strengths and limitations.
- [6]Food allergy - NHS
- [7]Sthenia — Official overview
Also worth reading
- From macros to meals: build your 7-day meal planTurn your calorie and macro targets into a week of meals: menu ideas, portion adjustments and a method for putting together your grocery list.
- Calories and macros for a cut: calculate a realistic targetEstimate your maintenance calories, set a deficit and work out your macros, then check whether your targets fit the meals you actually eat.
- Cutting meal plan for strength training: review your week before changing your intakeSeparate planned meals, actual intake and uncertainties to review your cutting meal plan, without automatic rules for changing calories.