Fitness Diet Apps: The Big Lie About Calories Burned

The Myth of App-Calculated Calories

You use an app that tells you burned 450 calories during your workout? This estimate is probably wrong by 20 to 90%. Here is why science says these calculations are impossible without specialized equipment.

Why BMI is Useless

Most apps use BMI (Body Mass Index) as their calculation base. The problem?

• A 200lb bodybuilder will be classified as obese according to BMI
• A sedentary 155lb person with 30% body fat will be normal
• BMI completely ignores body composition (muscle vs fat)
• It does not account for bone density or fat distribution

Caloric Formulas: Averages from Last Century

Apps use formulas like Harris-Benedict (1918) or Mifflin-St Jeor (1990). These equations:

• Are based on population averages from specific groups
• Do not account for your unique genetics
• Ignore your metabolic history (yo-yo dieting, etc.)
• Have a 10 to 30% margin of error even in best conditions

What Would Actually Be Needed to Measure

To know your real caloric expenditure, you would need:

• Indirect calorimetry - Measuring your O2 consumption and CO2 production (000-5000)
• DEXA Scan - Precise body composition bone/muscle/fat (50-300 per scan)
• VO2max test - Real aerobic capacity in a laboratory
• Hormonal analysis - Thyroid, cortisol, testosterone that influence metabolism

NEAT: The Invisible Factor

NEAT (Non-Exercise Activity Thermogenesis) represents calories burned outside exercise: walking, fidgeting, standing. This factor:

• Varies from 200 to 900 kcal/day between individuals
• Is impossible to measure by an app
• Can compensate or cancel your gym efforts
• Changes based on your fatigue and stress levels

Metabolic Adaptation: Your Body Adapts

After a few weeks of dieting, your metabolism slows down. Apps cannot detect:

• The reduction in basal metabolism of 10 to 25%
• The increase in muscular efficiency (fewer calories for same effort)
• Hormonal changes (leptin, ghrelin)

The Danger: Diets Based on Lies

Millions of people eat 1200 kcal/day because an app decided so. Consequences:

• Accelerated muscle mass loss
• Guaranteed yo-yo effect
• Eating disorders
• Chronic fatigue and performance decline

The Smart Rabbit Approach: Performance, Not Calories

At Smart Rabbit, we made a different choice: not pretending to measure the unmeasurable. Our AI focuses on:

• Your performance progression (weights, reps, time)
• Your subjective recovery and energy levels
• Adapting your training program, not your plate

Because ultimately, a good personalized training program will have more impact on your body composition than any approximate calorie counter.