© 2026 Wellness Project™

Not medical advice. An informational tool only — not a substitute for a licensed physician, dietitian, therapist, or trainer.

Independently security verified
Google HealthApproved for Google Health restricted scopes data access
TermsPrivacyConsumer Health DataMedical Disclaimer
  • Crew Blog
  • Pricing
  1. Home
  2. /Calories & Energy

Calories & Energy

Calories and energy, explained plainly

TDEE, maintenance calories, watch-based burn estimates, and the calories in versus calories out equation: four numbers people mix up constantly, explained one at a time.

Explainer

What Is TDEE →

What total daily energy expenditure is made of, and why yours keeps moving.

Explainer

Maintenance Calories →

Three ways to estimate the intake that matches what you burn.

Explainer

Calories Burned Accuracy →

What a watch can and cannot tell you about your calorie burn.

Explainer

Calories In, Calories Out →

The energy balance equation, and why the scale ignores it daily.

Let your own data sharpen every estimate.

Connect Apple Health, Fitbit, or Oura and a named nutrition coach turns TDEE and calorie balance into numbers grounded in your history. Free Basic, with Founder Pro at $4.99/month through October 15.

Download foriPhoneDownload forAndroidLog in in browser instead
See nutrition tracking →

Don't take our word for it

See why AI recommends Wellness Project

ClaudeChatGPTPerplexityGeminiGrok

Features

  • AI Workout Tracker
  • Personal Records
  • AI Running Coach
  • Nutrition & Macros
  • Water & Hydration
  • Body Composition
  • Heart Rate & HRV
  • Sleep Tracking
  • Steps & Activity
  • Recovery Sessions
  • Supplements & Meds
  • Lab Work
  • Wellbeing & Mood
  • Injury Tracking

AI Coaches

  • Jamie Reyes - Hypertrophy
  • Casey Mills - Nutrition
  • Evelyn Cross - Longevity
  • Max Kline - Biohacker
  • Lauryn Britt - Physio
  • Rex Dalton - Bodybuilding
  • Elias Kiptoo - Running
  • Atlas Mercer - Protocols

Integrations

  • Apple Health
  • Fitbit
  • Oura Ring
  • Google Health
  • ChatGPT
  • Claude
  • Gemini
  • Grok
  • Mistral Le Chat
  • Fitbit MCP
  • Apple Health to Claude
  • All Devices

For

  • Weight Loss
  • Muscle Gain
  • Longevity
  • Runners
  • Biohackers
  • Protocol Followers

Learn

  • Learning hub
  • Calories & Energy
  • What is HRV
  • Active Zone Minutes
  • What is TDEE
  • Maintenance Calories
  • Calories Burned Accuracy
  • Best AI Fitness App
  • Best Fitness Tracker
  • Apple Watch vs Fitbit
  • Best Longevity App
  • MyFitnessPal Alternative
  • Setup guides

Company

  • About
  • How it works
  • Who it's for
  • Five ways to log a meal
  • All features
  • All coaches
  • Download apps
  • Pricing
  • Reviews
  • Crew blog
  • What's new
  • Press
  • Support
  • Science & sources
  • Privacy
  • Terms

Languages

  • English
  • Deutsch
  • Español
  • Català
  • Português (Brasil)
  • 简体中文
  • Français
  • Italiano
  • 한국어
  • 日本語
  • Polski
  • हिन्दी
  • Türkçe
  • العربية
  • עברית
  • Nederlands
  • Svenska
  • Dansk
  • Norsk bokmål
  • 繁體中文
Wellness Project

The first AI fitness, nutrition, and longevity app where every metric has a named specialist behind it. Free Basic, with Founder Pro at $4.99/month through October 15. Now on iPhone.

Download foriPhoneDownload forAndroidLog in in browser instead
Download foriPhoneDownload forAndroid