What are macros? Slide your calories and see the grams

You will see the word "macros" everywhere: on food labels, in apps, in diet talk. It is short for macronutrients, the three nutrients your body needs in large amounts and that provide energy: carbohydrate, protein and fat. This guide shows what they are, how grams turn into calories, and what a day can look like.

The three macros in one minute

• Carbohydrate (bread, rice, pasta, fruit, potatoes, oats) is the body's main quick fuel. It gives about 4 kcal per gram.
• Protein (fish, eggs, dairy, meat, beans, lentils, tofu) helps build and repair tissue. It also gives about 4 kcal per gram.
• Fat (olive oil, nuts, oily fish, butter, avocado) is a concentrated energy store and carries some vitamins. It gives about 9 kcal per gram, more than twice the others.

Alcohol is not a macro in the usual sense, but it does carry energy: about 7 kcal per gram. These per-gram figures are standard averages used on labels (the Atwater factors), so real foods differ a little.

Try it: grams from calories

Pick a daily calorie amount and a split. The split is the share of your calories that comes from each macro. The tool turns it into grams using 4, 4 and 9 kcal per gram.

Macros tell you where your calories come from. Calories tell you how much. Neither needs to be exact to work.

What do the health bodies say?

The European Food Safety Authority (EFSA) suggests that adults get roughly 45–60% of their energy from carbohydrate and 20–35% from fat. For protein, EFSA's reference intake for adults is 0.83 g per kg of body weight a day, which is a level meant to cover almost everyone, not a target to hit exactly. Higher-protein and lower-carb splits are popular, and research on them is mixed, so treat them as options, not rules.

Notice that the "Lower carb" button above falls outside the usual carbohydrate range. That is fine to look at, but it is a bigger change to how you eat. See our low-carb guides before trying it.

Do you need to track macros?

Most beginners do not. A plate with vegetables, a protein food, a carbohydrate food and a little fat already lands close to a balanced split. Tracking grams can help if you are curious or have a specific plan with a professional, but it can also become stressful. If counting makes you anxious, or you have or had an eating disorder, skip it and talk to a doctor or dietitian.

Quick reality checks

• Macros do not replace food quality. 50 g of carbohydrate from lentils and from sweets have very different fibre and vitamins.
• Labels are rounded and bodies differ by 10% or more, so an exact number is false precision.
• Not medical advice. If you have a condition, are pregnant or breastfeeding, or take medication (especially for diabetes or blood pressure), talk to a doctor before changing how you eat.

Sources

• EFSA: European dietary reference values for nutrient intakes (carbohydrate and fat ranges)
• EFSA: Dietary reference values for protein (0.83 g/kg)
• FAO: Food energy, methods of analysis and conversion factors (4, 4, 9 and 7 kcal per gram)