The Mathematics of Fat Loss
Weight loss essentially comes down to thermodynamics. To lose 1 lb of body fat, you must create a deficit of approximately 3,500 calories. (In metric terms, to lose 1 kg, you need a deficit of roughly 7,700 calories).
TDEE - Goal = Deficit. If your body burns 2,500 calories (TDEE) and you eat 2,000 (Goal), your deficit is 500.
Why "Slow and Steady" Wins
It is tempting to starve yourself to move the date closer, but aggressive deficits often backfire.
- Metabolic Adaptation: Your body lowers its BMR to save energy, making it harder to keep losing weight.
- Muscle Loss: Your body breaks down muscle tissue for fuel, which ruins your physique and lowers your metabolism further.
Frequently Asked Questions
Why isn't my weight loss linear? ▼
You might eat perfectly for a week and see the scale stay the same. This is often due to water retention masking fat loss. Fat cells fill with water as they empty of triglycerides. Eventually, a "Whoosh" effect occurs.
Should I calculate exercise calories? ▼
It's safest to treat exercise calories as a "bonus." Fitness trackers often overestimate calorie burn by 20-50%. If you eat back all the calories you think you burned, you might accidentally erase your deficit.