What are macros? A simple explanation
Macronutrients are the three major categories of nutrients that provide energy. Every food contains some combination of them:
- Protein: 4 calories per gram. Builds and repairs muscle, supports immune function, highly satiating.
- Carbohydrates: 4 calories per gram. Primary fuel source for the brain and muscles during exercise.
- Fat: 9 calories per gram. Essential for hormones, brain function, and fat-soluble vitamin absorption.
Alcohol provides 7 calories per gram but is not a macronutrient. Fibre is a type of carbohydrate that provides minimal calories and is tracked separately.
Step 1: Calculate your targets
Before tracking, you need numbers to track towards. The process:
- Calculate your TDEE (Total Daily Energy Expenditure) — use our TDEE Calculator
- Apply your goal adjustment: subtract 300–500 kcal for fat loss, eat at TDEE for maintenance, or add 200–300 kcal for muscle gain
- Set protein first: 1.6–2.0g × body weight in kg
- Set fat at 25–30% of total calories
- Fill remaining calories with carbohydrates
Example: 75 kg person, fat loss goal, TDEE 2,200 kcal
Target calories: 2,200 − 400 = 1,800 kcal
Protein: 75 × 2.0 = 150g (600 kcal)
Fat: 1,800 × 28% = 504 kcal ÷ 9 = 56g
Carbs: 1,800 − 600 − 504 = 696 kcal ÷ 4 = 174g
Step 2: Choose a tracking tool
A food tracking app is essential for beginners. The most popular and most comprehensive options:
- MyFitnessPal: Largest food database, barcode scanner, integrates with fitness apps. Free version is sufficient for most users.
- Cronometer: More accurate micronutrient data, better for people also tracking vitamins and minerals.
- Nutrfy / Macrofactor: More expensive but uses AI to adjust targets based on actual weight trends.
Start with MyFitnessPal if you are a beginner — its database size and user-friendliness make it the easiest to build the habit with. Use the barcode scanner for packaged foods and the search function for whole foods.
Step 3: Weigh your food (at least initially)
This is non-negotiable in the beginning. Visual portion estimates are notoriously inaccurate — research shows people underestimate portions by 20–40% on average, and even experienced trackers miss up to 20%. A digital kitchen scale (£10–20) is the most impactful purchase you can make for nutrition tracking.
Weigh everything raw before cooking for the most accurate readings, as cooking changes the weight of foods (meat loses 20–30% weight when cooked due to water loss; pasta and rice approximately double in weight). Most food databases provide both raw and cooked values — just be consistent.
Step 4: Build a core of simple meals
The biggest macro-tracking mistake beginners make is trying to track every meal from scratch immediately. Instead, build a core of 8–12 simple, high-protein meals you rotate through. Once you have logged them a few times, the macros become automatic and tracking takes less than 5 minutes per day.
Save meal combinations in your tracking app as custom meals so you can log them with a single tap rather than entering each ingredient individually. This dramatically reduces the friction of daily tracking.
The 80/20 approach: when perfection is the enemy of progress
You do not need to hit your macros perfectly every day to get results. Aim to be within 5g of your protein target and within 10% of your total calories. Weekly averages matter more than daily precision — if one day is higher, a slightly lower day later in the week balances it out.
After 4–8 weeks of consistent tracking, most people develop an intuitive understanding of the macro content of common foods and can transition to more relaxed tracking — using the detailed daily logs for occasional check-ins rather than every single day.