Track nutrition and fitness via webhook with OpenAI, Google Sheets and Slack alerts

AI Nutrition Tracker with Webhook, OpenAI, Google Sheets & Slack Alerts

This workflow is an AI-powered nutrition and fitness tracking system built in n8n. It receives user input via webhook, analyzes food or activity using AI, updates daily calorie and protein intake in Google Sheets and sends alerts via Slack when limits or risks are detected. It also resets daily metrics automatically using a scheduled trigger.

Quick Start Guide (Fast Implementation)

Connect your Google Sheets account with required columns. Configure OpenAI API credentials. Set up Slack integration for alerts. Deploy the Webhook node for receiving user input. Enable the Schedule Trigger for daily reset. Test by sending a sample message (food/activity) to the webhook.

What It Does

This workflow automates real-time nutrition tracking by processing user input such as food consumption or physical activities. When a user sends a message through a webhook, the system fetches their profile data from Google Sheets and validates their existence before continuing.

The input is then analyzed using an AI model that classifies it as food or activity. Based on this classification, it estimates calories, protein intake, calories burned and identifies potential health risks. The processed data is combined with existing user metrics to maintain an updated daily summary.

Additionally, the workflow monitors calorie thresholds and risk patterns. If a user exceeds their daily calorie target or shows unhealthy behavior patterns, alerts are sent to Slack. A scheduled process resets all users’ daily metrics, ensuring accurate tracking for each new day.

Who’s It For

Fitness app developers Health and wellness platforms Personal trainers and nutritionists Automation engineers building health tracking systems Businesses managing user diet and activity tracking

Requirements to Use This Workflow

n8n instance** (self-hosted or cloud) Google Sheets account** with a structured sheet OpenAI API credentials** Slack workspace** with API access Basic understanding of webhook usage

Required Google Sheets Columns: Name Phone (used as unique identifier) Goal Daily_Calorie_Target Consumed_Calories Protein Last_Meal Status Risk_Count

How It Works & How To Set Up

Step 1: Configure Webhook

Node:** Receive User Input Set webhook path (e.g., /diet-input) This endpoint will receive user messages (food/activity input).

Step 2: Connect Google Sheets

Node:** Fetch User Data Map Phone column with incoming webhook data (body.phone). Ensure correct Sheet ID and Sheet Name.

Step 3: Validate User

Node:** Validate User Exists Ensures only valid users are processed.

Step 4: Configure AI Analysis

Node:** AI Nutrition Analyzer
Uses OpenAI model to: Detect input type (FOOD / ACTIVITY) Estimate calories & protein Detect risks Generate suggestions and replies Node:** AI Model (GPT) Ensure OpenAI credentials are properly connected.

Step 5: Process Data

Node:** Process Nutrition Data
Updates: Total calories, Protein intake and Risk count. Handles both food intake and activity adjustments.

Step 6: Monitor Thresholds

Node:** Check Calorie Threshold Sends Slack alert if calorie limit is exceeded.

Step 7: Risk Detection

Node:** Check Health Risk: Sends alert if any risk is detected. Node:** Check Critical Risk: Sends critical alert if risk count >= 3.

Step 8: Respond to User

Node:** Send API Response
Returns: AI-generated reply, calories consumed and daily total.

Step 9: Update User Data

Node:** Update User Data Writes updated metrics back to Google Sheets.

Step 10: Daily Reset Automation

Node:** Daily Reset Trigger Node:** Fetch All Users → Reset Daily Stats
Resets: Calories = 0, Protein = 0, Risk Count = 0, Status = NEW_DAY.

How To Customize Nodes

AI Prompt (AI Nutrition Analyzer):** Modify calorie logic, risk definitions or add new dietary rules. Calorie Threshold:** Change comparison logic based on different fitness goals. Slack Messages:** Customize alert messages and formatting. Google Sheets Mapping:** Add more fields like carbs, fats or water intake. Webhook Input Structure:** Adjust input format if integrating with mobile apps or chatbots.

Add-ons (Extend Functionality)

Add WhatsApp/SMS notifications for user alerts. Integrate with mobile apps for real-time tracking. Add meal history logging. Include weekly/monthly analytics dashboards. Add AI meal recommendations based on user goals. Integrate wearable data (steps, workouts).

Use Case Examples

Fitness App Backend:** Automatically track user diet and activity in real time. Personal Trainer Dashboard:** Monitor client calorie intake and risks. Corporate Wellness Programs:** Track employee health metrics and send alerts. Diet Coaching Automation:** Provide AI-based suggestions and feedback. Health Monitoring Systems:** Detect unhealthy patterns and escalate alerts.

Troubleshooting Guide

| Issue | Possible Cause | Solution | | :--- | :--- | :--- | | Webhook not receiving data | Incorrect webhook URL | Verify webhook path and method | | User not found | Phone mismatch in Sheets | Ensure phone format matches input | | AI response parsing fails | Invalid JSON from AI | Adjust prompt to enforce strict JSON | | Slack alerts not sent | Incorrect Slack credentials | Reconnect Slack API | | Data not updating in Sheets | Column mapping issue | Verify matching column (Phone) | | Calories not updating | Parsing or logic issue | Check code node calculations | | Daily reset not working | Schedule trigger configuration | Verify interval settings |

Need Help?

If you need assistance setting up this workflow, customizing AI logic or building advanced automation features, our n8n development team at WeblineIndia is here to help.

We specialize in:

n8n workflow automation AI-powered business solutions Custom integrations and scaling systems

📩 Reach out to WeblineIndia to accelerate your automation journey and build powerful, production-ready workflows tailored to your needs.