LINE Food Photo Nutrition Analysis with Gemini to Google Sheets

Turn LINE food photos into nutrition logs (automatically)

This n8n workflow listens to LINE Messaging API webhooks, uses Google Gemini to analyze uploaded food images, saves the photo to Google Drive, records nutrition estimates in Google Sheets, and replies to the user in LINE with a clear nutrition summary.

What this workflow does

• Receives LINE messages via a webhook (POST) whenever a user sends something through the LINE Messaging API.
• Validates the message type and checks whether the incoming message is an image.
• Downloads the image binary from the LINE data API using the LINE channel access token.
• Analyzes the photo with Gemini to determine if it contains food, estimate the meal name, and generate nutrition values.
• Parses Gemini’s JSON response and keeps the original image binary for later steps.
• If it’s food: uploads the image to Google Drive, appends the nutrition record to Google Sheets, and sends a nutrition/advice reply back in LINE.
• If it’s not food: replies in LINE asking the user to send a clearer food photo.

Use cases

• Building a photo-to-nutrition bot for dietary tracking using LINE and n8n.
• Logging meals from user-submitted photos into Google Sheets for quick reporting.
• Creating an operator-friendly workflow that stores evidence photos in Google Drive alongside nutrition estimates.

Technical details

• Core nodes/workflow logic: webhook, if, switch, code, HTTP Request, Google Drive, Google Sheets.
• Uses Google Gemini (PaLM) API credentials in n8n to perform nutrition analysis from the food image.
• Requires LINE webhook setup and a secure LINE channel access token for Authorization headers.
• Needs Google Drive OAuth2 to upload photos and Google Sheets OAuth2 to append nutrition results.