What are macros and why do they matter?
Macronutrients (macros) are the three main dietary energy sources: protein (4 kcal/g), carbohydrates (4 kcal/g), and fat (9 kcal/g). Total calorie intake controls weight gain or loss, but the macro split determines body composition — how much of that weight change is fat vs. muscle. High protein preserves muscle during a cut; sufficient carbohydrates fuel performance; adequate fat supports hormones. Tracking macros is more precise than just counting calories.
How much protein do I need per day?
The evidence-based range for muscle building and preservation is 1.6–2.2 g of protein per kg of bodyweight per day (0.73–1.0 g/lb). Aim for the higher end during a calorie deficit or if over age 40 to counteract muscle-protein breakdown. A 75 kg person needs roughly 120–165 g of protein daily. Spreading protein over 3–5 meals of 30–40 g maximises muscle protein synthesis (the leucine threshold per meal). Whey, chicken, fish, eggs, and Greek yogurt are high-quality sources.
What is the best macro split for fat loss (cutting)?
For cutting, a common evidence-based split is: Protein 30–35% of calories (high, to preserve muscle), Fat 25–35% (for hormones and satiety), Carbohydrates 35–45% (fuels training). Example for 1,800 kcal: ~155 g protein, ~60 g fat, ~185 g carbs. Adjust carbs and fat to personal preference — some people perform better on higher carbs for gym sessions; others prefer more fat and fewer carbs. Protein should remain non-negotiable.
What is the best macro split for muscle building (bulking)?
For bulking: Protein 25–30% of calories, Carbohydrates 45–55% (glycogen fuels training, supports anabolism), Fat 20–30%. Example for 3,000 kcal: ~185 g protein, ~375 g carbs, ~75 g fat. Carbohydrates are prioritised because they replenish muscle glycogen, support insulin-mediated nutrient delivery, and power high-volume workouts. Protein above 2.2 g/kg shows diminishing returns in trained individuals.
What is a ketogenic macro split and who is it suited for?
Keto limits carbohydrates to under 50 g/day (~5% of calories), with fat at 65–75% and protein at 20–30%. This forces the body into ketosis — producing ketones from fat as the primary fuel source. Keto can be effective for fat loss and may benefit people with type 2 diabetes, epilepsy, or metabolic syndrome. Downsides: adaptation takes 2–4 weeks (keto flu), it can impair high-intensity athletic performance due to reduced glycogen availability, and requires strict adherence.