How to Track Macros: Complete Beginner Guide
Master macronutrient tracking to optimise your nutrition for weight loss, muscle gain, or maintenance. The science-backed approach used by professional athletes and coaches worldwide.
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What Are Macros and Why Do They Matter?
Macronutrients — or macros — are the three main nutrients your body needs in large amounts: protein, carbohydrates, and fats. Unlike micronutrients (vitamins and minerals), macros provide energy in the form of calories and form the foundation of your diet. Understanding and tracking them gives you a level of control over your body composition that no other dietary approach can match.
The beauty of macro tracking is its flexibility. Unlike restrictive diets that ban entire food groups, macro tracking lets you eat whatever you want as long as you hit your targets. This approach, sometimes called flexible dieting or IIFYM (If It Fits Your Macros), has been shown in research to produce equivalent body composition results to rigid meal plans while being significantly more sustainable long-term.
The Three Macronutrients Explained
Builds and repairs muscle tissue, supports immune function, produces enzymes and hormones, and helps you feel full longer. The most important macro for body composition. Your body cannot store excess protein efficiently, so consistent daily intake is essential.
Your body's preferred energy source for high-intensity exercise and brain function. Stored as glycogen in muscles and liver. Carbs are not the enemy — they fuel your workouts, support recovery, and regulate mood. The amount you need depends on your activity level.
Essential for hormone production (including testosterone), vitamin absorption (A, D, E, K), cell membrane integrity, and long-term energy. Fats are calorie-dense, so they are easy to overconsume. Aim for mostly unsaturated sources with some saturated fat.
Step 1: Calculate Your Daily Calorie Needs (TDEE)
Before setting macros, you need to know your Total Daily Energy Expenditure (TDEE). This is the total number of calories you burn each day, including your basal metabolic rate (BMR), the thermic effect of food, non-exercise activity (NEAT), and exercise itself.
The simplest method is a bodyweight multiplier. It is not perfectly accurate, but it gives you a solid starting point. You will refine from there based on real-world results over the first 2-3 weeks.
| Activity Level | Description | Multiplier (kcal/lb) |
|---|---|---|
| Sedentary | Desk job, little to no exercise | 12–13 |
| Lightly Active | 1–3 gym sessions per week | 13–14 |
| Moderately Active | 3–5 gym sessions + some walking | 14–16 |
| Very Active | 6–7 sessions + active lifestyle | 16–18 |
| Extremely Active | Athlete or physical labour job | 18–20 |
Worked Example
A 180lb person who trains 4 days per week (moderately active):
180 × 15 = 2,700 kcal/day (maintenance)
For fat loss: 2,700 − 400 = 2,300 kcal/day
For muscle gain: 2,700 + 300 = 3,000 kcal/day
Step 2: Set Your Macro Split
Once you have your calorie target, the next step is splitting those calories across the three macronutrients. The key principle is: set protein first (it is the most important), then fats (minimum threshold for health), and fill the rest with carbs.
For Fat Loss
Prioritise protein to preserve muscle mass during a deficit. Keep fats high enough for hormonal health. Carbs are lower but still present to fuel training. A 300-500 calorie deficit is the sweet spot — aggressive enough to see results, mild enough to maintain performance.
40%
Protein
30%
Carbs
30%
Fats
Example (2,300 kcal): 230g protein | 172g carbs | 77g fat
For Muscle Gain
Increase carbs to fuel intense workouts and support recovery. Protein stays high. A 200-300 calorie surplus minimises fat gain while supporting muscle growth. Going much higher just adds unnecessary body fat.
30%
Protein
45%
Carbs
25%
Fats
Example (3,000 kcal): 225g protein | 338g carbs | 83g fat
For Maintenance / Recomp
Eating at maintenance while training hard allows slow body recomposition — building muscle and losing fat simultaneously. This works best for beginners and those returning from a break.
30%
Protein
40%
Carbs
30%
Fats
Example (2,700 kcal): 203g protein | 270g carbs | 90g fat
Step 3: Choose a Protein Target
Protein is the single most important macro to get right. The current body of evidence suggests the following targets based on your goal:
| Goal | Protein Target | Why |
|---|---|---|
| Fat Loss | 1.0–1.2g per lb | Preserves muscle in a deficit, high satiety |
| Muscle Gain | 0.8–1.0g per lb | Maximises MPS, surplus provides extra protection |
| Maintenance | 0.8–1.0g per lb | Supports recovery and body composition |
| Endurance | 0.6–0.8g per lb | Repair + adequate carbs for fuel |
Step 4: Start Tracking
Now you have your numbers, it is time to actually track. Here is a practical step-by-step process for your first week of macro tracking:
Get a food tracking app
MyFitnessPal, Cronometer, or MacroFactor are all solid choices. Set your calorie and macro targets in the app. MyFitnessPal has the largest food database, Cronometer is the most accurate for micronutrients, and MacroFactor uses AI to adapt your targets over time.
Buy a digital kitchen scale
This is non-negotiable for the first few months. You will be shocked at how inaccurate eyeballing is — most people underestimate portions by 20-40%. A basic scale costs £5-10 and pays for itself immediately. Weigh everything raw/uncooked for accuracy.
Track everything for 7 days
Log every single thing that enters your mouth for one full week. This includes cooking oils, sauces, drinks, and those “just one bite” moments. This awareness phase is where most people have their biggest revelations about their actual intake.
Review and adjust
After your first week, review: Did you feel energised? Were you hungry? Did your weight move in the right direction? Adjust your targets if needed. The initial numbers are a starting point, not gospel. Real-world data always trumps calculations.
High-Protein Food Cheat Sheet
Struggling to hit your protein target? Here are the most protein-dense foods per 100 calories:
| Food | Protein per 100g | Calories per 100g | Protein per 100 kcal |
|---|---|---|---|
| Chicken breast | 31g | 165 | 18.8g |
| Turkey breast | 29g | 135 | 21.5g |
| Egg whites | 11g | 52 | 21.2g |
| White fish (cod) | 23g | 105 | 21.9g |
| Fat-free Greek yogurt | 10g | 59 | 16.9g |
| Whey protein | 80g | 370 | 21.6g |
| Prawns | 24g | 99 | 24.2g |
Common Mistakes That Sabotage Your Progress
- Not tracking cooking oils and sauces.
One tablespoon of olive oil is 120 calories. Two tablespoons used to cook your chicken adds 240 invisible calories to your meal. Always measure oils, dressings, and sauces.
- Eyeballing portions instead of weighing.
Research consistently shows people underestimate portions by 20-40%. A “tablespoon” of peanut butter scooped casually is often 2-3 tablespoons. Weigh it.
- Forgetting liquid calories.
A large latte is 200-300 calories. A glass of orange juice is 120. A pint of beer is 200. These add up fast and are easy to miss.
- Being too restrictive.
The goal is 90% compliance, not 100% perfection. If you hit your macros within 5-10g on most days, you will see excellent results. Obsessive perfection leads to binge-restrict cycles.
- Not adjusting over time.
As your body changes, your calorie needs change. Reassess every 4-6 weeks. If weight loss stalls, you may need to reduce calories by 100-200 or add more activity, not slash 500 immediately.
- Only tracking on good days.
Track on weekends, holidays, and bad days too. This is where the real data lives. Most people eat well Monday to Friday and undo their deficit on Saturday and Sunday.
When to Stop Weighing Everything
Macro tracking is a skill, not a lifelong obligation. After 3-6 months of consistent tracking, most people develop a strong intuitive sense of portions. At that point, you can transition to a more relaxed approach:
- Phase 1 (Months 1-3): Track everything meticulously. Weigh all food. Build the habit and the knowledge base.
- Phase 2 (Months 3-6): Track but estimate familiar meals. Weigh only new or calorie-dense foods.
- Phase 3 (6+ months): Intuitive eating with periodic check-ins. Track for 1 week every month or two to ensure you have not drifted.
The long-term goal is not to track forever — it is to develop an understanding of food so deep that you naturally make good choices without an app.
Key Takeaways
- Calculate your TDEE, then set a calorie target based on your goal (deficit, surplus, or maintenance)
- Set protein first (0.8-1.2g per lb), then fats (0.3-0.4g per lb), fill the rest with carbs
- Use a food tracking app and digital kitchen scale for the first 3+ months
- Track everything — including oils, sauces, drinks, and weekend meals
- Aim for 90% compliance, not 100% perfection
- Reassess and adjust every 4-6 weeks based on real-world results
- Macro tracking is a skill to learn, not a lifelong requirement
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