“Macros” is short for macronutrients: the three nutrients your body needs in large amounts — protein, carbohydrate and fat. Every calorie you eat comes from one of them (or from alcohol). Understanding them is the difference between eating by number and eating with intention.
The three macros and their calories
- Protein — 4 calories per gram. Builds and repairs muscle, keeps you full, and costs the most energy to digest.
- Carbohydrate — 4 calories per gram. Your body’s preferred quick fuel, especially for the brain and hard exercise.
- Fat — 9 calories per gram. Essential for hormones, cell membranes and absorbing certain vitamins. Calorie-dense, so portions matter.
Protein: the priority macro
If you get one macro right, make it protein. It preserves muscle in a calorie deficit, blunts hunger, and has the highest thermic effect. Most people benefit from 1.6–2.2g per kg of bodyweight.
Carbs: fuel, not the enemy
Carbs aren’t inherently fattening — excess calories are. They power your workouts and your brain. Favor whole sources (oats, rice, potatoes, fruit, beans) over refined ones for steadier energy and more fiber.
Fat: essential in the right amount
Dietary fat is necessary, but at nine calories per gram it adds up fast. Prioritize sources like olive oil, nuts, seeds, avocado and fatty fish, and keep an eye on portions.
How to balance them
A flexible starting split for many goals: protein around 30%, carbs 40%, fat 30% — adjusted to your preference and activity. There’s no single magic ratio; protein sufficiency and total calories matter most.
Tracking macros sounds fiddly, but a photo-based tool like Fotocal estimates them from your plate, so you can see your protein, carbs and fat without manual math.
Key takeaways
- Protein and carbs have 4 cal/g; fat has 9 cal/g.
- Prioritize protein to protect muscle and control hunger.
- Carbs aren’t the enemy — choose whole sources.
- There’s no single perfect ratio; total calories and protein come first.