Macronutrients Explained: Proteins, Carbs, and Fats
Master the three macronutrients, understand their functions, and learn optimal ratios for your health and fitness goals.
What Are Macronutrients?
Macronutrients (or "macros") are the three main types of nutrients your body needs in large quantities to function properly: protein, carbohydrates, and fats. Unlike micronutrients (vitamins and minerals) which you need in smaller amounts, macros provide the energy and building materials your body requires every day.
Each macronutrient provides a different number of calories per gram: protein and carbohydrates provide 4 calories per gram, while fat provides 9 calories per gram. Understanding the ratio and types of macros you consume is crucial for achieving health goals like weight loss, muscle gain, or athletic performance.
Protein: The Building Block Macronutrient
What Does Protein Do?
- • Builds and Repairs Muscle: Protein provides amino acids needed to build muscle tissue, essential for strength and recovery.
- • Supports Immune Function: Antibodies that fight infection are made of protein.
- • Increases Satiety: Protein is the most satiating macronutrient, helping you feel full longer.
- • High Thermic Effect: Your body burns 20–30% of protein calories digesting it, the highest of all macros.
- • Hormone and Enzyme Production: Many hormones and enzymes are protein-based.
How Much Protein Do You Need?
- General recommendation: 0.8g per kilogram of body weight
- For muscle gain: 1.6–2.2g per kilogram
- For weight loss: 1.2–1.6g per kilogram (helps preserve muscle)
- For sedentary adults: 0.8g per kilogram minimum
Best Protein Sources
Animal-Based Protein
- • Chicken breast (31g/100g)
- • Beef (26g/100g)
- • Fish (20–25g/100g)
- • Eggs (6g per egg)
- • Greek yogurt (10g/100g)
- • Cottage cheese (11g/100g)
Plant-Based Protein
- • Lentils (9g/cooked cup)
- • Chickpeas (15g/cooked cup)
- • Tofu (15–19g/100g)
- • Tempeh (19g/100g)
- • Nuts and seeds (5–6g/oz)
- • Whole grains (3–8g/cup)
Carbohydrates: Your Primary Energy Source
What Do Carbohydrates Do?
- • Primary Energy Source: Your brain and muscles prefer glucose from carbs for fuel.
- • Brain Function: Your brain uses 120g of glucose daily—carbs are essential for focus and memory.
- • Athletic Performance: Carbs fuel intense exercise and help with recovery.
- • Fiber for Digestion: Whole-grain carbs provide fiber for gut health.
- • Mood and Sleep: Carbs increase serotonin, improving mood and sleep quality.
Types of Carbohydrates
Simple Carbs (Monosaccharides & Disaccharides)
Quickly absorbed sugar. Examples: white bread, candy, soda, white rice. Best consumed around workouts only.
Complex Carbs (Polysaccharides)
Slower digestion, stable energy. Examples: oatmeal, sweet potatoes, brown rice, whole wheat bread. Best for daily consumption.
Fiber
Indigestible carbs that support gut health. Aim for 25–30g daily from vegetables, fruits, and whole grains.
How Many Carbs Do You Need?
- Sedentary: 2–3g per kilogram body weight
- Lightly active: 3–5g per kilogram
- Moderate exercise: 5–7g per kilogram
- Intense training: 7–10g per kilogram
Fats: Essential for Health
What Do Fats Do?
- • Hormone Production: Fats are essential for testosterone, estrogen, and other hormones.
- • Vitamin Absorption: Fat-soluble vitamins (A, D, E, K) require fat to be absorbed.
- • Brain Health: Your brain is 60% fat; DHA and EPA omega-3s support cognitive function.
- • Cell Membrane Integrity: Fats form the structure of cell membranes.
- • Satiety: Fat slows digestion and promotes fullness.
Types of Dietary Fat
Unsaturated Fats (Healthy) ✓
Reduce inflammation and support heart health. Examples: olive oil, avocados, nuts, fatty fish, seeds.
Saturated Fats (Moderate)
Okay in moderation (less than 10% of calories). Examples: coconut oil, butter, full-fat dairy, red meat.
Trans Fats (Avoid) ✗
Harmful, increase heart disease risk. Found in processed foods and fried items. Banned in many countries.
How Much Fat Do You Need?
- General recommendation: 0.5–1.5g per kilogram body weight
- Minimum: 20% of daily calories (essential fatty acids)
- Maximum: 35% of daily calories
- Omega-3: 1–2g daily from fish oil or flax
Optimal Macronutrient Ratios
There's no single "perfect" macro ratio—it depends on your goals and preferences. Here are evidence-based guidelines:
Balanced Diet (General Health)
45–65% carbs, 10–35% protein, 20–35% fat
Best for: Overall health, steady energy, sustainable
High Protein (Muscle Gain & Weight Loss)
40% carbs, 30% protein, 30% fat
Best for: Building muscle, preserving lean mass during cutting
Low Carb (Keto-ish)
20–30% carbs, 30% protein, 40–50% fat
Best for: Some people find this easier for weight loss; may need adaptation
High Carb (Endurance Athletes)
60–65% carbs, 15–20% protein, 20–25% fat
Best for: Fueling intense endurance training
How to Track Your Macronutrients
Step 1: Calculate Your Calorie Goal
Use our calorie calculator to find your TDEE (Total Daily Energy Expenditure).
Step 2: Choose Your Macro Split
Pick a macronutrient ratio based on your goal (see chart above).
Step 3: Calculate Grams
Example: 2,000 calorie diet, 40/30/30 split
Carbs: 2,000 × 0.40 = 800 calories ÷ 4 = 200g
Protein: 2,000 × 0.30 = 600 calories ÷ 4 = 150g
Fat: 2,000 × 0.30 = 600 calories ÷ 9 = 67g
Step 4: Use a Tracking App
Popular options:
- MyFitnessPal (largest food database)
- Cronometer (micronutrients too)
- Lose It! (simple interface)
- FatSecret (community-driven)
Track Your Nutrition
Start with our calorie calculator to determine your daily caloric needs and macronutrient targets.
Calculate Your Macros →