The Mifflin-St Jeor equation (1990) is considered more accurate for most modern populations, especially those with average or higher body fat. The Harris-Benedict equation (1918, revised 1984) tends to slightly overestimate BMR. For general use, Mifflin-St Jeor is recommended.

A safe deficit is 250–500 kcal/day, leading to approximately 0.25–0.5 kg loss per week. Deficits above 1,000 kcal/day can cause muscle loss and nutritional deficiencies and should only be pursued under medical supervision.

TDEE (Total Daily Energy Expenditure) is the total number of calories your body burns daily, including all physical activity. It's calculated by multiplying your BMR by an activity level factor ranging from 1.2 (sedentary) to 1.9 (extra active).

Macronutrients are distributed from your target calories based on the selected split. Protein and carbs provide 4 kcal/g while fat provides 9 kcal/g. For example, in a Balanced split (30% protein, 40% carbs, 30% fat), each macro's grams are calculated from those percentages of your target calorie intake.