The Ultimate Guide to Understanding Macronutrients

What are macronutrients?

"Macro" means large. Macronutrients are the nutrients you need in large amounts to give your body energy and building materials: carbohydrates, protein and fat.

They are different from micronutrients, such as vitamins and minerals, which you need in much smaller amounts. The NHS describes vitamins and minerals as nutrients your body needs in small amounts to work properly.

You do not need to be a scientist to use this idea. The plain-English message is to eat a mix of all three, mostly from whole foods, and to pick the healthier types within each group.

This guide explains each macronutrient, what a healthy balance looks like and how to put it on your plate.

Carbohydrates: your main energy source

Carbohydrates are in bread, rice, potatoes, pasta, oats, fruit, vegetables, beans and sugary foods. Your body breaks them down into glucose, which fuels your brain and muscles.

The NHS says starchy foods should make up just over a third of the food you eat, based on the Eatwell Guide.

Wholegrain versus refined

The NHS recommends choosing wholegrain varieties where possible. It says they give a slow release of energy, contain more fiber and help you feel full for longer. It also notes that many cereal products are refined and can be high in added salt and sugar, so it is worth checking labels.

Fiber is a carbohydrate too

The NHS says adults should aim for 30 g of fiber a day, though most people currently average about 20 g. Good sources include wholemeal bread, oats, brown rice, pulses, vegetables and fruit.

The NHS also says adequate fiber is associated with a lower risk of heart disease, stroke, type 2 diabetes and bowel cancer.

A myth to drop

Carbs do not have to be the enemy. The NHS says starchy foods contain fewer than half the calories of fat, gram for gram, though how you cook and serve them matters.

Protein: for building and repair

Protein helps build and repair muscles and other tissues. The NHS says meats such as chicken, pork, lamb and beef are rich in protein. Fish, eggs, dairy, beans, lentils, nuts and tofu are other options.

The NIDDK lists seafood, lean meats, beans, nuts and low-fat dairy among nutrient-rich foods.

Choosing your protein

• Include a protein food at each meal.
• Aim for at least 2 portions of fish a week, with 1 being oily fish, as the NHS suggests.
• Choose lean cuts and poultry without skin. The NHS says the more white you can see on meat, the more fat it contains.
• If you eat more than 90 g of red or processed meat a day, the NHS suggests cutting down to 70 g a day on average.
• Add beans, lentils and tofu for plant-based protein and fiber.

The NHS notes that eating a lot of red and processed meat probably increases the risk of bowel cancer, and that processed meats can be high in salt.

Use our protein calculator for a starting point on how much you need.

Fat: needed, but choose wisely

Fat provides energy, helps you absorb some vitamins and supports cells. But it is very energy-dense, and the type matters.

The NHS says eating too much saturated fat can raise LDL, or bad, cholesterol in your blood, while replacing saturated fat with some unsaturated fat can help lower cholesterol.

• Saturated fat: found in fatty meat, butter, cheese, cream, biscuits, cakes and pastries. The NHS gives limits of 30 g a day for men and 20 g a day for women.
• Unsaturated fat: found in olive and rapeseed oil, nuts, seeds, avocados and oily fish.
• Trans fat: found in small amounts in meat and dairy and in partially hydrogenated oils. The NHS says the recommended maximum is about 5 g a day.

Read more in our article on the top 5 healthy fats.

How much of each do you need?

People often ask for exact percentages. Official UK guidance focuses on food groups, not strict macro splits. The Eatwell Guide, as described by the NHS, puts starchy foods at just over a third of your plate, with fruit and vegetables and other groups making up the rest.

• Starchy carbohydrates: just over a third of your food.
• Fruit and vegetables: at least 5 portions a day.
• Protein: some at each meal, with fish twice a week.
• Fat: small amounts, mostly unsaturated.
• Fluids: the NHS suggests 6 to 8 glasses a day.

Your needs vary with your age, size, activity and health. If you want a personalized macro plan, a registered dietitian can build one for you.

Putting macros on your plate

You do not need a food scale to eat well. A simple plate does the job.

• Fill about half your plate with vegetables and fruit.
• Add a portion of protein.
• Add a portion of starchy carbohydrate, choosing wholegrain where you can.
• Add a small amount of healthy fat, such as olive oil, nuts or avocado.

Our guide on how to build a balanced plate goes into more detail, and weekly meal planning shows how to plan a week.

A sample day

• Breakfast: oats with milk, fruit and seeds.
• Lunch: a lentil and vegetable soup with wholemeal bread.
• Snack: yogurt and an apple.
• Dinner: baked salmon, brown rice and broccoli.

This day has carbohydrates from oats, bread, rice and fruit, protein from milk, lentils, yogurt and fish, and fat from seeds, fish and a little oil.

It is one example of many possible patterns.

Reading macros on food labels

Food labels list carbohydrates, protein and fat, and often break them down further into sugars, saturates and fiber. You can use them to compare products quickly.

The NHS advises reading labels and choosing products with more green than amber or red, and it warns that many cereal products can be high in added salt and sugar.

• Compare products using the per-100 g column.
• Check saturated fat, sugars and salt first.
• Look for higher fiber in bread, cereals and grains. The NHS says high-fiber foods have 6 g or more of fiber in every 100 g.
• Notice the serving size. It may be smaller than what you actually eat.

Our guide on how to read a nutrition label walks through this step by step.

Macronutrient myths

Myth 1: Carbs make you fat

No single nutrient does that. Weight change depends on your overall intake and activity. The NHS notes that starchy foods contain fewer than half the calories of fat, gram for gram.

Myth 2: You need huge amounts of protein

Most people can meet their needs with regular meals that include a protein food. Protein powders and extra supplements are not needed by most people.

Myth 3: All fats are bad

Unsaturated fats from fish, nuts, seeds and plant oils are part of a healthy diet. The NHS suggests swapping saturated fats for unsaturated ones.

Myth 4: You must count every gram

Careful tracking is a tool some people use for specific goals. It is not required for healthy eating, and it can cause stress for some people.

Eating these foods on a budget

You do not need expensive products to get balanced macros. Everyday foods do the job, and many are cheap.

The NHS says fresh, frozen, canned and dried fruit and vegetables all count toward your 5 A DAY, so frozen and canned options are good value and keep for longer.

• Buy oats, rice, potatoes and wholemeal bread as your base carbohydrates.
• Use eggs, beans, lentils, canned fish and frozen chicken as protein.
• Choose oils such as rapeseed or olive oil and use small amounts.
• Buy frozen and canned vegetables.
• Cook in batches and freeze portions.

Plan your meals for the week and write a shopping list. Our guide on weekly meal planning shows how, and it also cuts food waste.

Read labels on canned foods for added salt or sugar, and rinse canned beans and vegetables where suitable.

A simple seven-day plan

Add one small change each day, and keep the earlier ones going. By the end of the week you will have several new habits.

• Day 1: choose a wholegrain carbohydrate for one meal.
• Day 2: add a protein food to breakfast.
• Day 3: add a vegetable to every meal.
• Day 4: swap one saturated fat source for an unsaturated one, such as butter for olive oil.
• Day 5: eat fish, or beans and lentils, for dinner.
• Day 6: check labels on two products you buy often.
• Day 7: review the week and choose one habit to keep.

You do not need to follow this plan exactly. Use it as a guide and swap foods for ones you enjoy, can afford and can get locally.

Aim for progress, not perfection. If a day goes off plan, start again the next day.

Common mistakes to avoid

• Cutting a whole macronutrient. Very restrictive plans are hard to sustain, and the NHS advises avoiding restrictive diets for rapid weight loss.
• Ignoring food quality. Two foods can have the same macros but very different nutrients.
• Forgetting fiber. The NHS says most people get about 20 g a day, not the recommended 30 g.
• Overdoing processed meat. The NHS notes processed meats can be high in salt.
• Copying someone else's numbers. Your needs depend on your body and goals.

Keep things simple, choose mostly whole foods and ask a dietitian for personalized advice.

Macros and your goals

Your goal changes how you use these ideas.

• Weight loss: focus on vegetables, protein and whole grains for fullness, and limit sugary drinks and high-fat extras. See our best foods for fat loss.
• Building strength: make sure you eat protein regularly, and enough carbohydrate to fuel training.
• General health: follow the balanced plate, eat plenty of fiber and limit salt, saturated fat and sugar.
• Medical conditions: follow your doctor's or dietitian's advice.

Recap: the main points

• Macronutrients are carbohydrates, protein and fat.
• Starchy foods should make up just over a third of your food, and wholegrain options are best.
• Include protein at each meal, and choose fish, beans and lean meats.
• Choose unsaturated fats over saturated fats.
• Use the balanced plate as a simple guide, and see a dietitian for a personalized plan.

Macronutrients: frequently asked questions

Want the full picture? Read our Healthy Eating Guide.

Related reading: Daily Protein Needs by Activity Level: How Much Do You Really Need? · Protein Needs by Activity Level

Sources and further reading

We checked the figures and guidance in this article against these sources. This article does not give personal medical advice.

• NHS: Starchy foods and carbohydrates
• NHS: Fat, the facts
• NHS: Meat in your diet
• NHS: How to get more fibre into your diet
• NHS: Eight tips for healthy eating
• NIDDK: Health tips for adults
• NHS: Vitamins and minerals

Want more? Head back to the Nutrition hub or read the Start Here guides.