This isn't medical advice. Macros are useful for normal people doing normal things; they aren't a prescription. If you have a medical condition, are pregnant or breastfeeding, are managing an eating disorder, or are taking medication that interacts with food, see a qualified professional and use this article as background reading, not a plan.

If you'd rather have an app handle the math from your kitchen instead of from a spreadsheet, the macro tracker app page is the short version of what follows.

Calories first, macros second

Macros are calories sliced into protein, fat, and carbs. You can't set macros without first deciding the calorie budget — they're constraints inside that budget.

Order of operations:

  1. Set a calorie target (maintenance, slight deficit, slight surplus).
  2. Set a protein target.
  3. Set fat to a sensible minimum.
  4. The rest is carbs.

That's it. Anything more elaborate is for people in competition prep. For an honest take on the calorie part, see how accurate are calorie trackers.

Protein: the only one that's non-negotiable

Protein is the macro you actually have to think about. Two reasons:

  1. Muscle preservation in a deficit. If you're in a calorie deficit (eating less than maintenance), low protein means losing muscle alongside fat. Higher protein keeps the muscle.
  2. Satiety. Gram for gram, protein keeps you fuller than carbs or fat. Higher protein → fewer "where did the rest of the day go" snacks.

The working number for most people: 1.6–2.2g of protein per kg of body weight per day. So a 70kg person aiming for the higher end: 154g/day. A 90kg person: 200g/day.

If that sounds like a lot, it is — for most people, hitting it requires conscious effort. Eggs at breakfast, yogurt at snack, real protein at dinner. If you only ever change one number, change this one.

Fat and carbs: the trade-off

After calories and protein are set, the calories left over are split between fat and carbs. There's no universally "right" split — it depends on what you actually like to eat and what keeps you full.

Practical defaults:

  • Active person, standard diet: 0.8–1.0g fat per kg, rest carbs.
  • Lower-carb preference: 1.2g fat per kg, rest carbs.
  • Higher-carb preference (endurance training): 0.6–0.7g fat per kg, more carbs.

Going below 0.6g/kg of fat is a bad idea (hormones, fat-soluble vitamin absorption, joint health). Going to zero carbs is a fad and not necessary for most goals.

The simple math (not the bro math)

Here's the entire calculation, for a 70kg person who wants to lose a little weight:

  1. Calories: maintenance (~2400 for a moderately active person) minus 400 = 2000 kcal.
  2. Protein: 1.8g × 70 = 126g → 126g protein (504 kcal).
  3. Fat: 0.9g × 70 = 63g → 63g fat (567 kcal).
  4. Carbs: 2000 − 504 − 567 = 929 kcal → 232g carbs.

Result: 2000 kcal / 126P / 63F / 232C. Round to nice numbers; nobody's checking.

Recalculate the calories every 6–8 weeks; recalculate the macros if your weight has shifted by 3+ kg. Otherwise, the same numbers work for months.

How to adjust over 4 weeks

Most people set their macros, fail to hit them perfectly week one, and quit. Don't quit. Adjust:

  • Week 1: Aim for "directionally correct". Get within 20g of protein, within 200 kcal of total.
  • Week 2: Tighten protein (within 10g) while keeping the calorie tolerance loose.
  • Week 3: Tighten calories (within 100 kcal) while keeping protein on target.
  • Week 4: You're hitting the numbers without thinking too hard.

If week 1 is impossible, your protein target is too high — drop it by 0.2g/kg and try again. Sustainable beats perfect.

Common mistakes

  1. Going too low on fat. "Low fat" diets often hit hormone walls. Don't drop below 0.6g/kg sustained.
  2. Counting protein from incomplete sources. Bread has protein; it's not the same as chicken's protein. Count "complete" sources separately if you're vegan/vegetarian.
  3. Counting "macros" but not calories. The macros add up to the calories. You can't have one without the other.
  4. Adjusting weekly based on the scale. Weight bounces day to day. Use 2-week rolling averages, not single weighings.
  5. Logging everything except the cooking oil. As covered in the calorie article — log it, always.

FAQ

Do I need to track macros every day?

For the first 4 weeks, yes — that's how you build the intuition. After that, most people get a feel for it and only spot-check (one full-tracking day every week or two).

What if I don't want to track at all?

Plate construction works as a fallback: half the plate vegetables, a palm-sized protein, a fist-sized starch, a thumb-sized fat. Less precise; more sustainable for life. Macros and plate construction aren't enemies; pick the one you'll actually do.

Can I hit my macros from a normal pantry?

Yes. How to hit your macros from your pantry goes deep on the eggs/yogurt/lentils/canned-tuna methods — the protein sources that don't require a special trip.

Should I use a macro app?

If you're tracking, yes — manual is too tedious to sustain. The macro tracker app page covers what to look for in one.