Macros for Weight Loss: Protein, Carbs & Fat

Macros for Weight Loss: A Complete Guide

Calories determine whether you gain or lose weight. But macronutrients — protein, carbohydrates, and fat — determine what kind of weight you lose, how you feel during the process, and how sustainable your results are. Getting your macros right can mean the difference between losing fat while preserving muscle and losing a mixture of both.

What Are Macronutrients?

Macronutrients are the three major categories of nutrients that provide energy (calories):

Protein (4 calories per gram)

• Builds and repairs muscle tissue
• Supports immune function and hormone production
• Has the highest thermic effect of food (TEF) — your body burns 20–30% of protein calories just digesting it
• Most satiating macronutrient — keeps you feeling full longer

Carbohydrates (4 calories per gram)

• Primary fuel source for the brain and high-intensity exercise
• Stored as glycogen in muscles and liver
• Provides fibre (essential for digestive health)
• Thermic effect: 5–10% of calories consumed

Fat (9 calories per gram)

• Essential for hormone production (including testosterone and oestrogen)
• Required for absorption of fat-soluble vitamins (A, D, E, K)
• Provides essential fatty acids the body cannot make
• Thermic effect: 0–3% of calories consumed

How to Calculate Your Macros from TDEE

Your Total Daily Energy Expenditure (TDEE) is the total number of calories you burn in a day. To lose weight, you eat below your TDEE. Your macro split determines how those calories are distributed.

Step 1: Determine Your TDEE

Use our calorie calculator or this estimate:

• Sedentary (desk job, little exercise): Body weight in kg × 28–30
• Lightly active (exercise 1–3 days/week): Body weight in kg × 31–33
• Moderately active (exercise 3–5 days/week): Body weight in kg × 34–36
• Very active (exercise 6–7 days/week): Body weight in kg × 37–40

Step 2: Set Your Calorie Deficit

For sustainable fat loss, subtract 400–600 calories from your TDEE. This produces approximately 0.5–0.75 kg (1–1.5 lbs) of fat loss per week.

Example: TDEE of 2,400 calories → Target: 1,900 calories

Step 3: Calculate Protein First

Protein is the most important macro for weight loss. Set it first:

• General recommendation: 1.6–2.2 g per kg of body weight
• If overweight (BMI 25–30): 1.6–2.0 g per kg of target body weight
• If obese (BMI 30+): 1.2–1.6 g per kg of target body weight, or 2.0–2.4 g per kg of lean body mass

Example: 80 kg person aiming for 2.0 g/kg = 160 g protein = 640 calories from protein

Step 4: Set Fat Intake

Fat is essential — never go below 0.5 g per kg of body weight, and most people function best at 0.8–1.2 g per kg.

• Minimum: 0.5–0.7 g per kg body weight
• Recommended: 0.8–1.2 g per kg body weight
• Higher fat preference: 1.0–1.5 g per kg body weight

Example: 80 kg person at 1.0 g/kg = 80 g fat = 720 calories from fat

Step 5: Fill Remaining Calories with Carbohydrates

After protein and fat, the remaining calories go to carbs.

Example: 1,900 total − 640 (protein) − 720 (fat) = 540 calories from carbs = 135 g carbohydrates

Final macros: 160 g protein / 135 g carbs / 80 g fat = 1,900 calories

Recommended Macro Splits for Weight Loss

The High-Protein Balanced Approach (40/30/30)

• 40% protein / 30% carbs / 30% fat
• Best for: Most people starting a weight loss program
• Advantages: High satiety, muscle preservation, balanced energy
• At 1,900 calories: 190 g protein, 143 g carbs, 63 g fat

The Moderate Approach (30/35/35)

• 30% protein / 35% carbs / 35% fat
• Best for: People who need more carbs for energy (active individuals, endurance exercise)
• Advantages: More fuel for workouts, sustainable long-term
• At 1,900 calories: 143 g protein, 166 g carbs, 74 g fat

The Lower-Carb Approach (35/20/45)

• 35% protein / 20% carbs / 45% fat
• Best for: People with insulin resistance, PCOS, or who feel better on fewer carbs
• Advantages: Better blood sugar control, reduced cravings for some people
• At 1,900 calories: 166 g protein, 95 g carbs, 95 g fat

When to Prioritise Protein

There are specific situations where pushing protein to the higher end (2.0–2.2 g/kg) is especially important:

• During a calorie deficit: Higher protein intake preserves lean muscle mass when losing weight
• Resistance training: Your muscles need amino acids for repair and growth
• Older adults: Protein requirements increase with age due to anabolic resistance
• Higher body fat percentage: Preserving lean tissue during weight loss becomes more critical
• Rapid weight loss: The faster you lose, the more muscle you risk losing without adequate protein

Carbohydrate Timing

When you eat carbs matters less than total daily intake, but strategic timing can help performance and recovery:

Pre-Workout (1–2 Hours Before)

• 30–50 g of moderate-glycaemic carbs (oatmeal, banana, rice)
• Provides fuel for higher-intensity training

Post-Workout (Within 2 Hours)

• 30–50 g of easily digestible carbs
• Replenishes muscle glycogen
• Combines well with protein for recovery

Before Bed

• Complex carbs (sweet potato, whole grains) can actually improve sleep quality by promoting serotonin and melatonin production
• Despite the myth, eating carbs at night does not inherently cause weight gain

Lower Carb at Other Times

• If you're on a lower-carb plan, concentrate your carbs around workouts and have lower-carb meals at other times

Healthy Fats: What to Include

Not all fats are equal. Prioritise:

Best Sources

• Monounsaturated: Olive oil, avocados, almonds, cashews
• Omega-3 polyunsaturated: Salmon, mackerel, sardines, walnuts, flaxseed
• Saturated (in moderation): Eggs, coconut oil, butter, dark chocolate

Limit or Avoid

• Trans fats: Hydrogenated oils, many processed and fried foods
• Excessive omega-6: Soybean oil, corn oil, sunflower oil in large quantities

Tracking Your Macros

Getting Started

1. Download a tracking app (MyFitnessPal, Cronometer, or Lose It are popular options)
2. Invest in a food scale — portion estimation is notoriously inaccurate
3. Log everything for 1–2 weeks to build awareness of what you're actually eating
4. Aim for 80% accuracy — perfect tracking is unnecessary and unsustainable

Common Tracking Pitfalls

• Forgetting cooking oils: A tablespoon of oil adds 120 calories and 14 g fat
• Eyeballing portions: A "serving" of peanut butter by eye is often 2–3 actual servings
• Ignoring sauces and dressings: These can add 100–300 calories per meal unnoticed
• Weekend leniency: Untracked weekends can erase a week's deficit

Meal Examples at Different Calorie Levels

1,500 Calories (130P / 120C / 58F)

Breakfast: Greek yoghurt (200 g) with berries (80 g) and almonds (15 g)

Lunch: Chicken breast (150 g) with mixed salad, olive oil dressing, and half an avocado

Dinner: Salmon fillet (140 g) with roasted vegetables and 100 g sweet potato

Snack: Protein shake with water

1,800 Calories (160P / 145C / 67F)

Breakfast: 3-egg omelette with spinach and feta, 1 slice whole grain toast

Lunch: Turkey mince stir-fry (180 g) with vegetables and 150 g brown rice

Dinner: Lean beef (150 g) with roasted Mediterranean vegetables and quinoa (100 g cooked)

Snack: Cottage cheese (150 g) with a handful of walnuts

2,200 Calories (185P / 200C / 78F)

Breakfast: Overnight oats (80 g oats, protein powder, banana, chia seeds, almond milk)

Lunch: Chicken thigh (200 g) with sweet potato (200 g), broccoli, and olive oil

Dinner: Pasta (80 g dry) with lean mince bolognese (150 g), side salad

Snacks: Protein bar, apple with peanut butter (20 g)

Adjusting Your Macros Over Time

Your starting macros won't be perfect. Adjust based on results:

• Not losing weight after 2 weeks: Reduce total calories by 100–200 (typically from carbs or fat)
• Losing weight too fast (more than 1% per week): Increase calories by 100–200
• Low energy in workouts: Increase carbs by 20–30 g, reduce fat slightly
• Constantly hungry: Increase protein by 15–20 g, consider adding more fibre-rich carbs
• Stalled after initial progress: Take a 1–2 week maintenance break at TDEE, then resume the deficit

Macros are a framework, not a rigid set of rules. Use them to guide your choices, build sustainable eating patterns, and achieve the body composition changes you're working toward.