Nutritional guide
Macronutrients explained
Understanding each macronutrient's function will help you distribute them intelligently according to your body composition goal.
What are macros
Macronutrients are the three energy pillars of the diet: proteins (4 kcal/g), carbohydrates (4 kcal/g) and fats (9 kcal/g). Their distribution directly affects body composition, satiety, energy and physical and mental performance.
Proteins and muscle mass
Proteins are the building blocks of muscle. In strength training or caloric deficit, increasing protein intake (1.6–2.2 g/kg) preserves muscle mass, increases satiety and slightly raises metabolic expenditure through its thermic effect (~25%).
Carbohydrates and insulin
Carbohydrates are the preferred fuel for the brain and muscles during intense exercise. They stimulate insulin, which facilitates glucose and amino acid uptake. During bulking phases, more carbohydrates improve performance and recovery. In deficit, reducing them helps control blood sugar.
Quick reference
Macro distributions by goal
Ratios used in this calculator, based on the most widely accepted recommendations in sports and clinical nutrition.
| Goal | Proteins | Carbohydrates | Fats | Suitable for |
|---|---|---|---|---|
| Deficit / Weight loss | 40% | 35% | 25% | Preserve muscle in caloric deficit |
| Maintenance | 30% | 45% | 25% | Energy balance and body composition |
| Bulk / Muscle gain | 30% | 50% | 20% | Maximise energy and muscle synthesis |
Frequently asked questions
All About Macronutrients
Evidence-based answers about proteins, carbohydrates, fats and how to distribute them.
Macronutrients are the three groups of nutrients that provide energy to the body: proteins (4 kcal/g), carbohydrates (4 kcal/g) and fats (9 kcal/g). Unlike micronutrients (vitamins and minerals), macros are consumed in large quantities and are the main energy substrate. Their proper distribution impacts body composition, performance, satiety and metabolic health.
For sedentary people, the minimum RDA is 0.8 g/kg of body weight. For those who exercise regularly, current evidence recommends between 1.6 and 2.2 g/kg to optimise muscle protein synthesis. In a caloric deficit, increasing protein to 2.0–2.4 g/kg helps preserve muscle mass while losing fat.
Not inherently. Body fat gain occurs from a total caloric excess, regardless of which macronutrient causes it. Carbohydrates are the main energy source for the brain and muscles during exercise. Quality matters: prioritise wholegrains, legumes, fruits and vegetables over refined sugars and white flour.
Dietary guidelines recommend that fats represent between 20% and 35% of total calories. Not going below 20% is important for maintaining hormone production (testosterone, oestrogens) and absorption of fat-soluble vitamins (A, D, E, K). Prioritise unsaturated fats: extra virgin olive oil, avocado, nuts and oily fish.
For losing or gaining weight, total calories are the most important factor. But macro distribution affects body composition, satiety, energy and performance. Ideally, control both: calories determine whether you lose or gain weight; macros determine what type of tissue (fat or muscle) you change. To start, first secure your minimum protein intake and adjust carbs and fats according to your preferences.
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