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How to log a meal

Three ways to do it. Pick whichever matches how lazy you're feeling.

KetoLens gives you three ways to log a meal, because not every meal deserves the same amount of effort. Use whichever fits the moment.

Which one should I use?

Quick gut-check before you start tapping.

📸 Snap Real food on a plate. You'd rather not type. ✍️ Manual Packaged food, recipes, or precise control. ⭐ Favourites You've eaten this before. Re-log in two taps.
Home screen with the plus button tapped, showing five options: Saved Favourites, Log Ketones, Manual Entry, Upload a Photo, Snap a Meal
Tap the green + on any tab to see all logging options.

📸 Snap a Meal

Best for: real food on a plate
  1. Tap the + button (bottom right of any tab).
  2. Tap Snap a Meal — the camera opens.
  3. Take a photo of your food.
  4. Wait a few seconds while the AI works out what you ate.
  5. Review the detected items and tweak anything that looks wrong.
  6. Tap Save Entry.

Already have a photo? Tap Upload a Photo instead and pick one from your gallery — same flow from there.

Good to know The AI is doing its best, but it isn't psychic — it can only see what's in the photo. If there are mushrooms hiding under that steak, it'll miss them. Use the Looks Wrong? button to add anything it didn't spot. Your corrections also help the app learn over time.

✍️ Manual Entry

Best for: packaged food & precise control
  1. Tap the + button.
  2. Tap Manual Entry.
  3. Type a meal name (e.g. "Lunch" or "Cheese omelette").
  4. Tap + Add Food Item for each food in the meal.
  5. For each food: enter the name, weight or quantity, and macros (see below).
  6. Tap Save.

Three ways to fill the macros

The macro fields (carbs, fat, protein, fibre, calories) are always editable. You've got three options for filling them — pick whichever's quickest:

1. Tap the sparkle ✨

KetoLens estimates the macros from the food name and weight using its food database. Best when you're not sure of the exact numbers.

Heads up On the free tier you'll see a padlock on the sparkle. Manual entry and previously-logged foods still work without limits.
Food item edit sheet for Scrambled Eggs at 100g with a red arrow pointing to the sparkle button on the right of the weight controls
The sparkle ✨ button — tap it to auto-estimate.
Food name field with the user typing Sc and a suggestion appearing for Scrambled Eggs 200g approximately 2.6g carbs from a previous log
Start typing — previously-logged foods appear as you type.

2. Pick a previously logged food

If you've logged the same food before, suggestions appear as you type the name. Tap one and you'll get a choice:

  • Just Name — fills only the food name. You enter the macros yourself.
  • Use Values — fills the name and the macros from your last log of this food. Then just tweak the weight or quantity if it's different this time.
Dialog asking Use previous values for Scrambled Eggs 200g approximately 2.6g carbs with two buttons Just Name and Use Values
The "Use previous values?" prompt that appears after picking a suggestion.

3. Type the macros by hand

All the macro fields are always editable. This is the right choice when you're working from a packet label or you know the exact values you want.

The little Weight / Qty toggle on the left of the amount row lets you switch between grams and counts (e.g. "1 fried egg" instead of "60g fried egg") — handy for things that don't really make sense by weight.

Food item sheet for one Fried Egg in quantity mode with all macro fields at zero ready for manual entry
Quantity mode — entering "1 Fried Egg" with macros to be filled in by hand.

⭐ Saved Favourites

Best for: meals you eat all the time

How to save a favourite

Meal detail page for Full English Breakfast with a red arrow pointing to the teal star button on the top right of the photo
The star sits on the top-right of the meal photo (or beside the meal name if there's no photo).
  1. Open any meal you've logged (tap it in your Diary).
  2. Tap the star ⭐ at the top-right of the photo (or next to the meal name for meals without a photo).
  3. That's it — the star turns teal and the meal is saved to your favourites.

Tap the star again to un-favourite. There's no confirmation — toggling is instant.

Where to find your favourites

Two entry points:

  • The + button → Saved Favourites — fastest when you're about to log a meal.
  • Diary tab → Favourites segment — switch from Timeline to Favourites at the top of the Diary to browse and search.
Diary with the Favourites segment selected, showing a search bar and one saved meal: Full English Breakfast with photo, ingredients summary, 32.9 to 37.5 grams net carbs, and 1077 calories
The Favourites segment of your Diary — your starred meals, searchable.

Re-logging a favourite

  1. Tap + → Saved Favourites (or open the Diary's Favourites tab).
  2. Pick the meal — search if you've got loads.
  3. The meal opens in Relog Meal mode, pre-filled with everything from the original.
  4. Tweak quantities, swap items, or leave as-is if nothing has changed.
  5. Tap Relog Now. A fresh entry is added to your Diary; the original favourite stays untouched.
Relog Meal screen with Full English Breakfast pre-filled and a red arrow pointing to the teal Relog Now button
Relog mode. Tap Relog Now to save it as a new entry.

🛠️ Date, time & re-logging

Two tools you'll find on every saved meal — useful when you forgot to log at the time, or you're eating the same thing again.

Change the date or time

  1. Open the meal from your Diary.
  2. Scroll to the Saved [date] at [time] label (small ✏️ pencil icon).
  3. Tap the label — the date and time pickers slide open.
  4. Pick a new date and/or time. Future dates are blocked.
  5. Tap Save Changes.

Log this meal again

  1. Open any saved meal from your Diary.
  2. Scroll down and tap Log this meal again (📋 copy icon).
  3. The meal is duplicated as a new draft you can tweak — adjust quantities, items, date or time.
  4. Tap Relog Now to save it as a fresh entry. The original stays exactly as it was.
Tip "Log again" is the same idea as Favourites, just one tap further away. Use it for meals you don't want cluttering your Favourites — yesterday's leftovers, a one-off restaurant order, etc.
Bottom of a meal edit page with a red box around the Saved date label, the Log this meal again button, and the Delete this meal button
The bottom of any saved meal: edit the date/time, re-log, or delete.

Quick comparison

Mode Best for Speed Needs AI?
📸 Snap New meals, real food ~10s for AI Yes
✍️ Manual Packaged food, recipes Instant (or ~3s with ✨) Optional
⭐ Favourites Repeat meals Instant No

Mix and match throughout the day. There's no "wrong" mode — the app just wants to know what you ate.

Next: the AI’s estimate isn’t gospel — here’s how to check it and fix what it got wrong.