"Macros" is short for macronutrients: the three components of food that provide energy — protein, carbohydrate and fat. Calories decide whether you gain or lose; the split between them decides what happens to your body composition and how you feel getting there.
| Macro | Calories per gram | Main role |
|---|---|---|
| Protein | 4 | Building and keeping muscle, fullness |
| Carbohydrate | 4 | Readily available energy, training performance |
| Fat | 9 | Hormones, absorbing vitamins |
Note that fat is more than twice as calorie-dense. That's why a "small" tablespoon of olive oil is 120 calories while a whole apple is about 80.
The common mistake is starting from an arbitrary percentage split like 40/30/30. It's better to set them by body weight, in this order:
Set first because it matters most. 1.6–2.2 g per kg, with the high end during a deficit. Full protein guide.
0.8–1 g per kg, and not below 0.6. Going under that for long stretches risks hormonal disruption.
Whatever calories remain. Carbs are the adjustment variable — they expand or contract to fit the target.
A 75 kg person, 2,000 calorie target, cutting:
That works out at 30% protein, 39% carbs, 31% fat — without setting any percentage up front.
Which matters more, calories or macros? Calories, by a wide margin. Get those right with reasonable protein and you've captured most of the result. Fine-tuning the carb-to-fat ratio matters mainly for athletes and people already lean chasing the last few percent.
No. The body doesn't switch to a different mechanism after a certain hour. The daily total is what counts. Some people sleep better with carbs in the evening, which is a perfectly good reason to put them there.
Not necessarily. When studies match calories and protein, differences in weight loss between diets are small. The best diet is the one you can actually keep doing.
Fibre is a carbohydrate but is barely absorbed as energy. It has a large effect on fullness, so it's worth watching — 25–35 g a day is a common recommendation.
Achalti sets protein, carb and fat targets from your weight and goal and shows what's left of each in real time — no spreadsheets, no manual maths.
This guide is general information based on mainstream nutrition recommendations. It is not personal medical or dietary advice.