How to log food with Claude

Claude can log meals, track nutrition, and analyze calorie trends when connected to a food database. This guide shows how to connect Claude (iPhone, Claude.ai, Claude Desktop, or Claude Code) to Zolt's free nutrition MCP server so you can log food through normal conversation, search the database, track macros, and review progress — all with editable drafts that confirm before saving.

Claude supports MCP natively across every platform: one-click OAuth on iPhone and Claude.ai, a terminal command for Claude Code, and a config file for Claude Desktop. Once connected, Claude searches Zolt's food database (USDA, restaurant menus, saved recipes) instead of estimating, shows you the proposed meal before saving, and keeps logs so trends persist across weeks.

What is the Zolt MCP server?

Zolt's MCP (Model Context Protocol) server connects Claude to your Zolt account. Claude can search foods, log meals, track weight, review trends, and analyze progress through conversation. Every write goes through an editable draft: Claude shows you the complete proposed meal with servings and macros, waits for your confirmation, and saves it only after you approve.

Free tier includes food, water, and weight logging with 30 daily food lookups and 3 months of history. Pro adds advanced analytics, full history, and higher limits.

Claude supports MCP on every platform. Setup takes under two minutes.

How to connect Claude.ai

Claude.ai (web) uses one-click OAuth setup.

Step 1: Open Connectors settings

  1. Go to claude.ai
  2. Click your profile or settings icon
  3. Select Customize → Connectors (or go directly to claude.ai/settings/connectors)

Step 2: Add Zolt as a custom connector

  1. Click Add custom connector
  2. Name it Zolt (or any name you prefer)
  3. Paste the MCP server URL:
https://mcp.zolthealth.com/mcp
  1. Click Add

Step 3: Connect and authorize

  1. Click Connect next to the Zolt connector
  2. A browser window opens for OAuth login
  3. Sign in to your Zolt account (or create one if you haven't yet)
  4. Tap Connect to authorize Claude
  5. Return to Claude.ai — the connection is active

You're done. Claude can now search foods, log meals, and read your Zolt data.

How to connect Claude on iPhone

The Claude iPhone app (iOS 17.4+) supports MCP with one-tap OAuth.

Step 1: Open Integrations settings

  1. Open the Claude app on iPhone
  2. Tap your profile icon (top right)
  3. Go to Settings → Integrations

Step 2: Add the Zolt connector

  1. Tap Add integration or Custom MCP server
  2. Paste the Zolt MCP URL:
https://mcp.zolthealth.com/mcp
  1. Tap Add or Connect

Step 3: Authorize with Zolt

  1. Safari opens for Zolt OAuth login
  2. Sign in to your Zolt account
  3. Tap Connect to authorize
  4. Return to Claude — you're connected

Now you can log food, track macros, and review trends from your iPhone through Claude.

How to connect Claude Code

Claude Code (CLI tool) uses a one-line terminal command, then browser OAuth.

Step 1: Run the add command

Open your terminal and run:

claude mcp add --transport http zolt-health https://mcp.zolthealth.com/mcp

Claude Code registers the Zolt MCP server and prepares OAuth.

Step 2: Trigger OAuth in Claude Code

In Claude Code, type:

/mcp

This opens your browser for Zolt login.

Step 3: Authorize

  1. Sign in to your Zolt account in the browser
  2. Tap Connect to authorize Claude Code
  3. Return to Claude Code — the connection is complete

Claude Code now has access to your Zolt data. You can log food, review logs, and analyze trends from the terminal.

How to connect Claude Desktop (API key method)

Claude Desktop does not yet support OAuth, so it uses a manual API key. This method requires Zolt Pro (OAuth connections work with the free tier).

Step 1: Generate an API key in Zolt

  1. Open the Zolt app on your iPhone
  2. Go to Settings → Experimental Features
  3. Enable MCP API Keys
  4. Tap Manage API Keys → Generate Key
  5. Copy the zhk_... key

Step 2: Edit Claude Desktop config

Open the Claude Desktop config file in a text editor:

macOS:

~/Library/Application Support/Claude/claude_desktop_config.json

Windows:

%APPDATA%\Claude\claude_desktop_config.json

Add the Zolt server:

{
  "mcpServers": {
    "zolt-health": {
      "type": "http",
      "url": "https://mcp.zolthealth.com/mcp",
      "headers": {
        "Authorization": "Bearer zhk_your_key_here"
      }
    }
  }
}

Replace zhk_your_key_here with your actual API key.

Step 3: Restart Claude Desktop

Quit and reopen Claude Desktop. Zolt appears in the available tools list.

How to log food with Claude

Once connected, tell Claude what you ate. Examples:

  • "Log 2 eggs and a coffee for breakfast"
  • "I had a Chipotle burrito bowl with chicken, brown rice, black beans, and cheese"
  • "Log 500mL of water"
  • "Copy yesterday's lunch to today but halve the rice"

Claude will:

  1. Search Zolt's food database for matches
  2. Show you the proposed meal with serving sizes, calories, and macros
  3. Wait for you to confirm or correct the draft
  4. Save the complete meal after you approve

Log from a photo

Attach a meal photo to your Claude conversation (iPhone, Claude.ai, or Claude Desktop) and ask:

  • "Log this as lunch"
  • "What's in this meal and how many calories?"

Claude's vision model identifies the foods and estimates portions, then searches Zolt for database matches. You see the complete proposed log before anything saves. The photo stays in Claude — Zolt receives only the food names.

Example prompts

  • "What did I eat yesterday?"
  • "How are my macros looking this week?"
  • "Am I hitting my protein target this month?"
  • "What's my average calorie intake over the last 7 days?"
  • "Log my weight at 175 lbs"
  • "What's my current TDEE and how is it trending?"
  • "Search for fage greek yogurt"
  • "What foods do I eat most often?"
  • "Copy yesterday's breakfast to today"
  • "Save this nutrition label as a custom food"

Claude can analyze trends, suggest meals that fit your remaining targets, and answer questions about your nutrition data across weeks and months.

How confirm-before-save drafts work

Every food log in Zolt goes through an editable draft:

  1. You ask Claude to log a meal
  2. Claude calls Zolt's resolve_food_log_draft tool
  3. Zolt searches the database and returns food matches with serving options
  4. Claude shows you the complete proposed meal: foods, servings, section (breakfast/lunch/dinner/snack), date, and macros
  5. You confirm, correct, or cancel
  6. On confirmation, Claude calls prepare_food_log, then confirm_action
  7. Zolt saves the meal in one atomic write

Nothing writes until you explicitly approve the displayed draft. This prevents accidental logs, wrong servings, and hallucinated food data.

The same confirmation workflow applies to:

  • Editing or deleting food logs
  • Logging weight
  • Setting weight goals
  • Weekly check-ins (updating calorie targets)
  • Saving custom foods or recipes
  • Logging workouts

Claude always shows you what will save before it commits.

Why log food with Claude instead of a traditional app?

Conversational logging: Describe the meal naturally. No tapping through screens, searching separately for each ingredient, or adding foods one by one. "I had scrambled eggs with cheese and toast" resolves all three items in one search.

Context across weeks: Claude reads your food history, recent meals, usual servings, and saved foods. When you say "log my usual breakfast," it knows what that means from your logs.

Trend analysis: Ask "How did my protein intake this month compare to last month?" or "Why did my TDEE estimate change?" Claude reads weeks of data and explains the pattern.

Editable drafts: Every proposed meal shows all foods, servings, and macros before saving. Correct portions or swap an item before committing.

Photo logging: Attach a meal photo, Claude identifies the foods, Zolt searches the database, you confirm the draft. No manual entry.

Alternative: log food with ChatGPT instead

ChatGPT also supports MCP through Developer mode (paid plans). Setup and features are similar to Claude.

See How to log food with ChatGPT for setup, accuracy expectations, and prompts.

Frequently asked questions

Is Claude food logging free?

Yes. Zolt's free tier includes food, water, and weight logging with 30 daily food lookups and 3 months of history. Claude (web, iPhone, Code) is also free. Claude Desktop requires an API key, which is Pro-only, but the other Claude platforms use OAuth and work with Zolt's free tier.

Can I use this on Claude Desktop without paying for Pro?

Not yet. Claude Desktop does not support OAuth, so it requires a manual API key, which is Pro-only. Use Claude.ai, Claude iPhone, or Claude Code for free OAuth-based access instead.

How accurate is Claude for nutrition data?

Plain Claude (without a database) estimates nutrition from training data and averages roughly 36% calorie error on test foods (similar to ChatGPT in published studies). With Zolt's MCP connection, Claude searches USDA data, verified restaurant menus, and nutrition labels — the same sources traditional calorie tracking apps use.

Does Claude see all my Zolt data?

Claude only fetches data you explicitly ask about. If you ask "What did I eat yesterday?" it reads yesterday's food logs. If you never mention workouts, it never reads workout data. Your MCP connection can be revoked at any time from Zolt Settings → API Keys (for API-key connections) or by disconnecting the integration in Claude settings (for OAuth).

What if I want to log on desktop but don't have Pro?

Use Claude.ai (web) instead of Claude Desktop. Claude.ai supports OAuth and works with Zolt's free tier. Open claude.ai in any browser, add Zolt as a connector, and authorize with one click.

Can Claude log restaurant meals?

Yes. Zolt's database includes verified nutrition data for 60+ restaurant chains (Chipotle, Cava, Chick-fil-A, Panda Express, Subway, In-N-Out, and more). Tell Claude what you ordered — for example, "Log a Chipotle chicken burrito bowl with brown rice, black beans, mild salsa, and cheese" — and it searches the menu database for matches.

See the full restaurant nutrition calculator list for covered chains.

Does Claude track macros?

Yes. Every Zolt food log includes protein, carbohydrates, and fat. Claude can show daily macro totals, weekly averages, adherence to protein targets, and macro trends over time. Ask "How are my macros this week?" or "Am I hitting my protein target?"

Can I log water or weight through Claude?

Yes. The same MCP connection covers water logging ("Log 500mL of water") and weight logging ("Log my weight at 182 lbs"). Claude can also review hydration trends and weight progress over time.

Track nutrition and body composition with Zolt

Zolt learns your real metabolism from weight trends and logged intake, then adapts calorie and protein targets as your body and goals change. Log through Claude, ChatGPT, iMessage, or the Zolt app — your adaptive TDEE updates automatically.

Download Zolt free on the App Store for iPhone.

Want to understand how Zolt calculates maintenance calories? Read Understanding Adaptive TDEE or try the TDEE calculator.