Integrations
Works through WhatsApp for end users, and the company offers a nutrition and calorie tracking API for gyms, fitness chains and wellness centers to embed in their own apps.
Rex Fit
Text a photo of your meal and get calories, macros and coaching back
Beginner API
What is Rex Fit?
Rex Fit is an AI chat bot tool. A WhatsApp based AI nutrition coach that logs meals from photos or text, tracks workouts, sends daily report cards and adds an AI body scanner for body metrics.
Rex Fit is a nutrition and fitness tracking assistant that lives inside WhatsApp. Rather than opening a dedicated logging app, a user sends a message describing a meal or attaches a photo of it, and the bot uses computer vision and AI to estimate the calories, protein, fats and carbs involved. The log builds up over the day without any manual entry on a form, and the assistant replies with context about how the day is going. The tool covers more than food. Users can tell it what they did in a workout (for example three sets of forty pushups) and it records the session in the same conversation. When someone is unsure what to train, they can ask for a workout suggestion and receive a recommendation tailored to their stated goals. Each day ends with a report card that summarizes intake and adds personalized feedback and tips on diet and lifestyle. Rex Fit also offers an AI body scanner, positioned as an alternative to BMI, which turns body measurements into insights for fitness and nutrition planning. In practice the product suits people who have repeatedly abandoned calorie counting because logging is tedious: beginners, busy professionals, and anyone who already lives in WhatsApp. It also speaks to athletes and gym members working on weight loss, muscle building or longevity, and the team advertises a nutrition and calorie tracking API aimed at gyms, fitness chains and wellness centers that want to embed the same capability in their own products. The competitive frame is the established food databases and macro trackers, along with newer photo based loggers. Rex Fit bets that conversation is stickier than forms, and users quoted on the site describe the daily messages as the accountability they were missing. The Drop, a pre-order wearable that automates nutrition capture further, shows where the company is heading.
How do you use Rex Fit?
1Open the WhatsApp chat with Rex
Use the WhatsApp link on the homepage to start a conversation with the Rex bot. The chat becomes your tracking surface for meals, workouts and questions.
2Tell Rex your goals
State what you are working toward, such as losing weight, gaining muscle or living healthier. The coaching feedback is framed around the goal you set.3Log your first meal
Send a photo of the plate or type a short description of what you ate. Rex estimates calories, protein, fats and carbs and records the meal for the day.4Record a workout or ask for one
Describe the session you completed, for example sets and reps, or ask Rex for a workout suggestion and receive a recommendation suited to your goal.5Read the daily report
At the end of the day check the report card for a summary of intake plus personalized feedback and lifestyle tips.6Try the AI body scanner
Use the body scanning feature to collect body metrics beyond BMI and feed those numbers into decisions about training and nutrition.
Pros and cons
Pros
- Logging happens by texting a photo or a short description, which removes the friction that kills most calorie tracking habitsAI
- Meals and workouts share one conversation, so daily context sits in a single thread instead of separate appsAI
- Daily report cards with personalized feedback create an accountability loop many users say they lackedAI
- AI body scanner offers an alternative to BMI for people whose shape does not fit the standard formulaAI
Cons
- Everything runs through WhatsApp, so anyone who avoids the messenger or wants a standalone app is poorly servedAI
- Nutrition estimates from photos are approximations, and the site gives no detail on portion accuracy or food database coverageAI
- No pricing is published on the homepage, so the cost of using the coach is unknown before startingAI
- The AI body scanner asks users to share body imagery, and the site does not explain how that data is stored or protectedAI
- The Drop wearable is a pre-order item with no shipping date on the page, so hardware buyers take on wait riskAI
How much does Rex Fit cost?
Features
Photo and text meal logging with calorie and macro estimates, workout logging and tailored workout suggestions, daily report cards with personalized diet and lifestyle feedback, an AI body scanner as an alternative to BMI, and a nutrition tracking API for partners.
Frequently asked questions about Rex Fit
Does Rex Fit have an API?
Yes, Rex Fit offers an API.How do you use Rex Fit?
The walkthrough on this page covers 6 steps: 1. Open the WhatsApp chat with Rex 2. Tell Rex your goals 3. Log your first meal 4. Record a workout or ask for one 5. Read the daily report 6. Try the AI body scanner.What platforms does Rex Fit support?
Rex Fit is available on Web App, iOS and Android.What does Rex Fit integrate with?
Works through WhatsApp for end users, and the company offers a nutrition and calorie tracking API for gyms, fitness chains and wellness centers to embed in their own apps.What are the limitations of Rex Fit?
Everything runs through WhatsApp, so anyone who avoids the messenger or wants a standalone app is poorly served. Nutrition estimates from photos are approximations, and the site gives no detail on portion accuracy or food database coverage. No pricing is published on the homepage, so the cost of using the coach is unknown before starting.
Status
StatusActive
Views0
Outbound clicks0
Added10/21/2026
Platforms
Web AppiOSAndroid
Pricing
Freemium
