Bmr Calculator

① Liver (~27%): The largest single metabolic contributor, responsible for detoxification, glycogen storage, and nutrient processing.

② Brain (~19%): Consumes continuous energy for neurotransmitter synthesis and electrical impulse signaling even during deep sleep.

③ Skeletal Muscle (~18%): Maintains core posture and resting muscle tone. The only organ whose metabolic rate can be expanded through resistance training.

④ Kidneys (~10%) & Heart (~7%): Fuel continuous blood filtration and 24/7 cardiovascular circulation.

⑤ Other Tissues (~19%): Adipose fat tissue, dermal skin layers, and gastrointestinal smooth muscle maintenance.

① Revised Harris-Benedict (1984) Equations:

- Men: $\text{BMR} = 88.362 + (13.397 \times W) + (4.799 \times H) - (5.677 \times A)$

- Women: $\text{BMR} = 447.593 + (9.247 \times W) + (3.098 \times H) - (4.330 \times A)$

② Mifflin-St Jeor (1990) Equations:

- Men: $\text{BMR} = (10 \times W) + (6.25 \times H) - (5 \times A) + 5$

- Women: $\text{BMR} = (10 \times W) + (6.25 \times H) - (5 \times A) - 161$

*(Where $W$ is weight in kg, $H$ is height in cm, and $A$ is age in years)*

① Calorie Deficit for Fat Loss: Subtract 300 to 500 kcal from your TDEE ($\text{Target} = \text{TDEE} - 400$) for sustainable weight loss. Never consume fewer calories than your BMR, as this triggers adaptive thermogenesis and muscle catabolism.

② Calorie Surplus for Lean Hypertrophy: Add 300 to 500 kcal to your TDEE ($\text{Target} = \text{TDEE} + 400$) alongside progressive overload resistance training.

③ Macronutrient Distribution Principles:

- Protein: $1.6\text{g} \sim 2.2\text{g}$ per kg of bodyweight to preserve lean mass.

- Fat: $20\% \sim 30\%$ of total calories to sustain hormonal function and cell membrane integrity.

- Carbohydrates: Fill remaining calories with complex carbs for athletic performance.