Macronutrients are the three primary nutrients your body uses for energy and structural functions: Protein (4 kcal/g), Carbohydrates (4 kcal/g), and Fat (9 kcal/g). Each plays a distinct role — protein repairs muscle, carbs fuel performance, and fat supports hormones and cell membranes.

For most active individuals, 1.6–2.2g of protein per kg of bodyweight daily is optimal for muscle retention or growth. Sedentary adults need less (~0.8g/kg). This calculator personalises your target based on your goal and activity level using research-backed formulas.

Yes — protein has the highest thermic effect of food (TEF), meaning your body burns more calories digesting it. It also preserves lean muscle during a caloric deficit and keeps you feeling fuller for longer, reducing overall calorie intake.

A classic muscle-gain split is roughly 30–35% protein, 40–50% carbohydrates, and 20–25% fat, in a caloric surplus of 10–15% above TDEE. Adequate carbohydrates are crucial for training performance and recovery — don’t cut them too low when bulking.

BMR (Basal Metabolic Rate) is the calories your body burns at complete rest. TDEE (Total Daily Energy Expenditure) multiplies your BMR by an activity factor to estimate real-world daily calorie burn. We use the Mifflin-St Jeor formula — the most validated equation for most adults.

A ketogenic diet typically consists of ~70% fat, 25% protein, and only 5% carbohydrates (usually under 20–50g net carbs). This forces the body into ketosis, burning fat as its primary fuel source. It can be effective for certain goals but requires medical guidance for some individuals.