"Macros" is one of those fitness words that's escaped the gym and entered everyday UK conversation. But what are they really, and is counting them worth the effort? Here's the no-nonsense version.
What "macros" actually means
Short for macronutrients — the three nutrients your body needs in large amounts:
- Protein — 4 calories per gram
- Carbohydrates — 4 calories per gram
- Fat — 9 calories per gram
(Alcohol is technically a fourth at 7 kcal/g, but isn't considered a macro you should be hitting targets for.)
Counting macros means tracking how many grams of each you eat per day, not just total calories.
Why bother counting macros?
Calories tell you how much you ate. Macros tell you what it was. Two people both eating 1,800 calories can have very different bodies:
- Person A: 180g carbs, 60g fat, 90g protein
- Person B: 100g carbs, 60g fat, 180g protein
Same calories, but Person B is far better set up for fat loss with muscle preservation. They'll feel fuller, hold onto muscle in a deficit, and probably have steadier energy.
Standard macro splits (UK guidelines)
UK government guidance (from the Eatwell Guide and SACN) suggests adults aim for roughly:
| Macro | % of daily calories |
|---|---|
| Carbohydrates | ~50% |
| Fat | ~30–35% (max) |
| Protein | ~15–20% |
This is the "general healthy adult" baseline. Active people, dieters and bodybuilders typically adjust upwards on protein.
Macro splits for specific goals
Fat loss (preserving muscle)
- Protein: 30–40% (1.6–2.2g per kg bodyweight)
- Fat: 25–30%
- Carbs: 35–45% (the remainder)
Muscle gain
- Protein: 25–30% (1.6–2.0g per kg)
- Fat: 25%
- Carbs: 45–50%
General health / maintenance (UK Eatwell-aligned)
- Protein: 15–20%
- Fat: 30–35%
- Carbs: 45–55%
Endurance training
- Protein: 15–20%
- Fat: 20–25%
- Carbs: 55–65%
Worked example
If your daily target is 2,000 kcal and you want to lose fat (40% protein / 30% fat / 30% carbs):
- Protein: 2,000 × 0.40 = 800 kcal ÷ 4 = 200g protein
- Fat: 2,000 × 0.30 = 600 kcal ÷ 9 = 67g fat
- Carbs: 2,000 × 0.30 = 600 kcal ÷ 4 = 150g carbs
That's a roughly fat-loss-friendly split for someone weighing about 75kg.
Should you count macros?
Yes, if...
- You've stalled on calories alone and want a more refined approach
- You're training seriously (gym 3+ times a week)
- You're trying to build muscle and need to make sure protein is high enough
- You enjoy data and find tracking motivating
No, if...
- You're new to nutrition — start with calories first
- Tracking food triggers anxiety or disordered eating thoughts
- You eat mostly whole foods and feel good — you probably don't need it
- You can't sustain the tracking long-term
The "flexible dieting" approach (IIFYM)
"If It Fits Your Macros" is a popular approach where any food is allowed as long as it fits your daily targets. It's psychologically easier than restrictive diets, but doesn't account for food quality — 200g of carbs from broccoli is very different to 200g from sweets.
A sensible middle ground: hit your macros from 80% whole foods, 20% flexible. That's enough room for a takeaway or biscuit without losing the nutritional benefits of real food.
Tracking apps used in the UK
- MyFitnessPal — biggest food database, includes UK supermarket products
- Cronometer — better for micronutrients (vitamins/minerals)
- Nutracheck — UK-built, smaller but more accurate UK product database
- Lose It! — simpler interface, calorie-focused
The bottom line
Macros are protein, fat and carbs. Most UK adults can ignore detailed tracking and just focus on hitting a protein target. Counting macros becomes useful when calories alone stop working or when you're training seriously. If tracking ever feels stressful, stop — it's a tool, not a moral obligation.
Sources: SACN (Scientific Advisory Committee on Nutrition), NHS Eatwell Guide, British Nutrition Foundation, International Society of Sports Nutrition position stands.