What do you need before you start?
IZeat is the calorie tracker inside ChatGPT, Claude or any other assistant. Tell the assistant you already use what you ate instead of searching for foods and entering them one by one. To do that in Claude you need three things. An IZeat account, created on the web with Google or with an email and a password; the six-digit code by email signs you in once the account exists. Claude, on the web, the desktop app or the iPhone app, all three of which can add a custom connector. And the address to paste, if you take the manual path: https://izeat.app/api/mcp.
There is nothing to install and no command to launch: IZeat is a remote server Claude connects to over HTTP, and a web page where you read the day. Connecting takes one tap or a few steps, once; afterwards, logging a meal is a sentence in a chat. Claude reads a described meal the way ChatGPT does, so how far to trust the figure a model gives applies here unchanged.
The iPhone path was tested on an iPhone on 7 September 2026, and it lives with the others on the connection guide. This page does not copy it: menus move, and a copy in an article is the one that goes stale first.
How do you connect IZeat to Claude?
From the connection guide, where a button opens Claude with the name and the address already filled in; you review them and confirm. A manual path exists too, and the same page carries it, along with the one for the iPhone app. The steps are not reprinted here on purpose: menus move, and one copy kept current beats two copies drifting apart.
What does not move is the shape of it. The sign-in is IZeat's own page rather than a Claude setting: it is where you say which IZeat account this Claude may write to, and the same Assistants page revokes it whenever you want. Nothing is installed on your machine either, because IZeat is a remote server Claude calls over HTTP.
How do you check it works before trusting it with a meal?
Ask one question that reads your account and records nothing: "Who am I in IZeat?" What proves the connection is that IZeat identifies the account: the answer names the account and the email the connection belongs to, and today's date in your time zone. A line beginning with "IZeat ·" is the convention the model is asked to keep, and it can be missing on a call that worked, so it is the account that settles it and not the prefix. If IZeat does not know your time zone yet, the reply says so; giving your city is a separate step, a profile change, and the reply to it is signed too. The answer reads:
“Who am I in IZeat?”
IZeat · Connected account: Sam Lee (sam@example.com). Today is Friday 11 September 2026 in Europe/Paris.
The first time, the assistant may also start a short setup: your first and last name, then the daily target you want to use. You can say "later" at any step; a missing name or target never blocks a meal. If it names an account that is not yours, stop and revoke the connection from the Assistants page before saying anything about food. A missing "IZeat ·" prefix is not the same thing, and nothing needs doing about it: the prefix is a convention the model is asked to keep, and it is the account named in the answer that tells you the connection works.
What do you say for the first meal, and what comes back?
Name the meal, the foods, and how much of each. A weight in grams or a volume in millilitres is best; a brand helps; say what a dish was cooked in. Claude is asked to follow IZeat's protocol: to ask what your words leave open, if anything, then to call IZeat once with the whole meal. Here is a real one, from Laetitia, who builds IZeat with Seb, on the morning of Saturday 5 September 2026, dictated to the Claude iPhone app in French and translated here from her export.
She said: "I want to record a breakfast, and it is in fact Saturday 5 September, 7:14 in the morning. So I am going to eat a kiwi, a fresh one, and a galette; look at the photo for the macros." The photo was the galette's nutrition label. Claude read the label, called IZeat once with both items, and answered from the receipt: breakfast recorded for Saturday 5 September, 256 kcal, 13 g of protein, 28 g of carbohydrate, 10 g of fat, with 1494 kcal and 107 g of protein left against her target. It then added, in its own voice, that this galette was the plain one, not the brown one from the day before, with half the fibre, and that 13 g of protein was light for her day. That remark is Claude reasoning over IZeat's figures; the figures are IZeat's.
Two minutes later she mentioned a protein bar bought for later. Claude asked for its label or its brand, because bars range widely, and offered to wait. She answered: "I would rather you wait until I have eaten it; I will tell you when." Claude wrote nothing. At 7:32 she sent the bar's label, and the second receipt came back: 217 kcal, 20 g of protein, 16 g of carbohydrate, 8 g of fat, source label, and the day so far at 473 kcal.
Read the receipt, not the chat around it. It begins with "IZeat ·", lists each food with its quantity in grams, the meal's calories and macros, then the day's total and, once you have set a target, what is left. Each row keeps its own source: the galette and the bar came from their labels; a food you name without a label is valued from a reference table for the grams you gave, and a dish nobody can look up is an estimate, marked as such. Ask "what is in my breakfast?" or open the web app to see the source row by row. If a figure is wrong, say the right one, and the row is updated with the day.
| What you say | What Claude is asked to do | What the receipt shows |
|---|---|---|
| "Breakfast: two eggs, 40 g of oats, 200 ml of whole milk" | Value the three from reference tables and record them | Three rows: oats and milk as reference values for the amounts you gave, the eggs at an assumed weight per egg that the receipt states, the meal total, the day so far |
| A photo of the yoghurt's label, "I had 125 g" | Read the label back with its units, then record | One row, source label, scaled to 125 g |
| "Lunch was chicken and rice" | Ask the weights, whether the rice is cooked weight, and the cooking fat, in one message | Nothing until you answer; then the rows with their sources |
| "Same breakfast as yesterday, without the milk" | Read yesterday's breakfast from IZeat and record today's with the change | The rows recorded today, the day so far |
| "The rice was 200 g, not 150" | Update the row through IZeat | The change and the new total; the previous state kept in the meal's history |
| "What is left for dinner?" | Read the day from IZeat and answer from it | A signed read: the day's meals, the total and what is left, nothing written |
Bottom line: a sentence with weights is recorded as said; a sentence without them costs one question; a question about the day writes nothing, but its figures are still signed by IZeat.
What do you do when it goes wrong?
Connected to Claude, IZeat is designed to make the diary easier to keep while you work toward your goal; when something is off, the receipt is what tells you, and these are the cases the connection guide records.
- A missing "IZeat ·" prefix. It is not a fault and not a test. The prefix is a convention the model is asked to keep, so a reply can lose it after a call that worked, and a question back from the assistant carries none at all. Whether the connection works is settled by the check question: ask "Who am I in IZeat?" and read whether it names your account.
- "Requires sign-in" was turned on. Claude then asks for a client id and a secret nobody has. Turn the switch off, or start the form again with it off: the name and the address are the whole form, and IZeat brings its own sign-in page when Claude hands you over.
- A second lunch is refused. There is one meal of each type per day; "for lunch I also had a yoghurt" adds to the lunch, and something eaten at another time goes under another meal type. The refusal is signed and ends with "Nothing was recorded".
- The date is wrong. Say the day in words, "yesterday", "Tuesday"; IZeat resolves it in your time zone and names it in every reply. If the time zone is wrong, say your city and it is stored.
- A photo of a plate got a number without a question. That is not the protocol; say the portion and the cooking fat and ask for the item to be corrected, and the row is updated with its source.
- A signed reply says the IZeat tools changed. Claude keeps the list of tools it loaded when the connector was added. If a meal comes back with a reply saying the tools changed and nothing was recorded, remove the IZeat connector and add it again once. A line starting with "New:" is a different thing: a capability announced once, with nothing to fix.
What this page will not settle: the menus, which move, and which the connection guide carries instead. And the record is only as good as the sentence: a weight said fixes the amount, not where the figure comes from, which the receipt says item by item; a weight left open is a question or an estimate that says so.
Frequently asked questions
Short answers to the questions people type, each one sourced above.
Can Claude track calories on its own, without IZeat?
It can value a described meal, and that is where it stops: a chat has no diary. A new conversation starts without the day, the total lives in your head, and a portion in a photo has nothing to stop a confident guess. Connected to IZeat, the same Claude is asked to record each meal you say with the source on each item, IZeat sums the day, and Claude reads it back when you ask, from the record rather than from memory.
Does this work in the Claude iPhone app?
Yes, as tested on an iPhone on 7 September 2026: the app adds a custom connector by itself, with a name, the address, and the "Requires sign-in" switch left off. On 4 September 2026 it could not, and we have no record of when that changed, which is why the step-by-step lives on the connection guide and not in this article.
What does the button on the Assistants page do?
It opens claude.ai in your browser with the connector's name and the address already filled in, so you review them and confirm instead of pasting; it is the same connector the manual path creates. We have not tested it from the desktop app or from a phone: there, the manual steps above are the ones to follow. Once confirmed, Claude brings you to IZeat's sign-in page; sign in, tap Allow, and ask the check question.
Is my IZeat data safe with Claude connected?
Claude can read and write your IZeat record only through the connection you authorised, for the account you signed into, and you can revoke it from your Assistants page at any time. IZeat's server receives only the tool request Claude sends, such as a meal to record, and returns only the account data needed to answer it; what you say to Claude itself is governed by Anthropic's own policy. The privacy page has the detail.
Do I have to set a target to log a meal?
No. A missing name or target never blocks a meal; the receipt then shows the meal and the day's total without a remainder. When you want a target, say it: "from Monday, 1 900 kcal and 130 g of protein". IZeat records it from that day, and every receipt after that ends with what is left. IZeat calculates no target for you; Claude can reason about one with you, outside IZeat, and IZeat stores what you choose.
Can I log by voice in Claude?
If you dictate the meal into Claude's text field, yes: it is recorded the same way as typed text, with the same questions when a weight or a fat is left open; whether Claude's voice mode can use a connector is not something we have tested. What matters is that the words carry the grams; "a big bowl of pasta" said aloud is still a portion nobody weighed, and it is recorded as an estimate marked as one.
How do I fix a mistake Claude made in my diary?
Say the right figure: "the rice was 200 g, not 150", "it was almond milk, not cow's milk". The row is updated through IZeat, the day is summed again, and the previous state stays in the meal's history. Undo shows what the last change did and asks before taking it back, within 48 hours. Every write returns a receipt, so a mistake is seen when it is made.
Does the same setup work in ChatGPT or Claude Code?
The connection does, with different menus: the ChatGPT desktop app adds an MCP server from its plugin settings, and Claude Code with one command in the terminal; there is a guide for each. Once connected, the meal is the same sentence and the receipt the same receipt, because the record and the protocol are IZeat's, whichever assistant you talk to.