Macro tracking — counting grams of protein, carbohydrates, and fat rather than just calories — gives you a more complete picture of what you're eating and why it's working (or not). This guide covers how to set your macros, how to track them, and how to use them for sustainable weight loss.
What Are Macros?
Macros (macronutrients) are the three nutrient groups that provide calories:
- Protein — 4 calories per gram. Essential for muscle maintenance, satiety, and metabolism support. Found in meat, fish, eggs, dairy, legumes.
- Carbohydrates — 4 calories per gram. Your body's preferred energy source. Found in grains, fruit, veg, legumes, sugar.
- Fat — 9 calories per gram. Required for hormone production, brain function, and fat-soluble vitamin absorption. Found in oils, nuts, dairy, fatty meat and fish.
Alcohol (7 cal/g) is technically a fourth macronutrient but is rarely tracked directly — its calorie impact shows up in your daily total.
Why Track Macros Instead of Just Calories?
You can lose weight by tracking only calories. But macro tracking gives you more control over what kind of weight you lose.
The most important example: protein. Two people in the same calorie deficit will get very different results if one eats 180g of protein per day and the other eats 60g. The high-protein person preserves significantly more muscle mass, maintains a higher metabolic rate, and feels fuller. Their body composition improves. The low-protein person loses weight but more of it is muscle — a worse outcome even at the same scale number.
Macro tracking makes protein intake visible and intentional. That's the core reason to do it.
How to Set Your Macros for Weight Loss
Start with your calorie target, then allocate macros within it. Use our TDEE calculator to find your maintenance calories, then subtract 300–500 to find your weight loss calorie target.
With that target set, allocate macros in this order:
Step 1: Set Protein (Non-Negotiable)
Set protein at 1.6–2.2g per kilogram of bodyweight. This range is supported by the scientific literature for preserving muscle in a calorie deficit.
Example: 75kg person → 120–165g protein per day → start at 150g as a round number.
Use our protein calculator for a personalised recommendation based on your goals.
Step 2: Set Fat (Minimum Threshold)
Set fat at a minimum of 0.8g per kilogram of bodyweight. Going below this threshold disrupts hormone production and fat-soluble vitamin absorption. Don't go lower than 50–60g total regardless of bodyweight.
Example: 75kg person → minimum 60g fat per day.
Step 3: Fill Remaining Calories with Carbohydrates
After protein and fat are accounted for, remaining calories come from carbohydrates.
Example calculation for a 75kg person at 1,900 calories/day:
- Protein: 150g = 600 calories
- Fat: 65g = 585 calories
- Remaining for carbs: 1,900 − 600 − 585 = 715 calories ÷ 4 = 179g carbs
- Final macros: 150P / 179C / 65F
Our macro calculator does this automatically — enter your details and get your personalised macro targets in seconds.
How to Track Your Macros
Three approaches, from most to least rigorous:
- Food scale + tracking app: Weigh everything, log in an app (MyFitnessPal, Cronometer, Nutracheck). Most accurate. Best for the first 4–6 weeks to calibrate your understanding of portion sizes.
- Portion-based tracking: Use visual guides (a palm of protein, a fist of carbs) without weighing. Less accurate but faster and more sustainable long-term. Works well once you've done some scale-based tracking and have a feel for portions.
- Meal plan tracking: Build or use a preset meal plan with known macros and repeat it. No daily logging required — you just follow the plan. PrepSmart generates plans with pre-calculated macros so you can track without logging every meal individually.
Common Macro Tracking Mistakes
Tracking protein in product weight, not cooked weight
100g of dry chicken breast and 100g of cooked chicken breast are very different — the raw version has more protein per gram because water hasn't been added. Log ingredients in their raw/dry state for consistency, or weigh cooked and use a cooked-weight database entry.
Ignoring liquid calories
Milk in coffee, olive oil in cooking, protein in protein shakes — these add up. A tablespoon of olive oil is 14g fat / 126 calories. It's easy to add 300–400 untracked calories through cooking fats and drinks alone.
Only hitting protein on gym days
Protein targets apply every day, not just training days. Muscle protein synthesis is elevated for 24–48 hours after exercise, meaning rest day nutrition matters. Hitting 150g protein Monday-Friday and 80g on weekends undermines the weekly average significantly.
Setting an unsustainably low fat target
Fat makes food taste good and keeps you full. Dropping fat too low to create a bigger calorie deficit increases hunger and reduces diet adherence. The minimum 0.8g/kg guidance exists for a reason — don't go below it.
How Long Until You See Results?
With consistent tracking at a 400–500 calorie deficit: expect 0.3–0.5kg of fat loss per week. Most people see noticeable changes in body composition (how you look and feel) within 4–6 weeks, even if the scale hasn't moved dramatically. Scale weight fluctuates day-to-day by 1–2kg due to water, glycogen, and food volume — measure weekly averages, not daily numbers.
Getting Started with a Macro-Tracked Meal Plan
The fastest path from zero to macro tracking is to start with a plan that already has the macros calculated. PrepSmart builds 7-day meal plans calibrated to your specific calorie and protein targets — every recipe has pre-calculated macros, and the shopping list is generated automatically.
Start with the macro calculator to set your targets, then generate your personalised meal plan around them. The plan handles the maths so you can focus on cooking and eating.