Fitness diet: what to eat to build muscle

How many calories should you eat to build muscle?

Building muscle requires the stimulus of strength training and energy to make new tissue. That extra energy is a calorie surplus: eating a little more than you expend. A review of energy surplus and hypertrophy suggests starting at around 350 to 480 kcal a day above maintenance needs [2].

This is a starting point, not a universal target. You then adjust it according to your progress.

Eating far more than that does not speed up muscle gain. Building muscle takes time, and a large surplus can increase body fat.

If you are new to strength training, you may build muscle even while eating enough to maintain your weight. A review of bodybuilding nutrition advises assessing progress over several weeks and adjusting the surplus more cautiously as you become more experienced [3]. A rise on the scale does not always mean muscle gain.

If you struggle to gain weight despite eating plenty, the approach is different. Find out more on our dietitian for weight gain page.

How much protein do you need each day, and how should you spread it out?

Protein provides the amino acids your muscles use to repair and grow after training. For athletes in general, the joint US and Canadian sports nutrition guidance gives a range of 1.2 to 2.0 g per kilogram of body weight per day [4].

If your goal is to build muscle, the range is 1.4 to 2.0 g per kilogram per day, enough for most people who train [1].

Distribution matters as well as the daily total. The recommendation is 20 to 40 g of high-quality protein, or around 0.25 g per kilogram, every three to four hours [1]. Three large eggs can be part of one of those servings, depending on the other foods in the meal.

People often claim that eating a lot of protein harms the kidneys. In healthy adults, one review found no difference in changes to kidney filtration between higher-protein and normal-protein diets [5].

That finding does not set a protein target for someone with kidney disease. If you have kidney disease, your nephrologist or dietitian will advise you on suitable amounts of protein, potassium, phosphorus and other minerals according to its stage. Eating more protein than you need can crowd other foods off your plate.

Carbohydrates and fats: fuel for every set

Protein gets most of the attention in the gym, but carbohydrates fuel strength training. The joint US and Canadian guidance puts needs at 3 to 5 g per kilogram per day with light activity [4]. With a moderate programme of around an hour a day, this rises to 5–7 g [4].

Glycogen is the carbohydrate stored in muscle. With those stores replenished, you can delay fatigue and complete demanding sets. How much you need depends on the length and intensity of your sessions.

Fats help produce hormones and absorb vitamins A, D, E and K. They should provide between 20% and 35% of your daily energy; dropping below 20% does not improve performance [4]. Prioritise extra virgin olive oil, avocado, nuts and oily fish.

What to eat before and after training

Eating well around a workout helps you start with energy and recover sooner. For your pre-workout meal, the recommendation is 1 to 4 g of carbohydrate per kilogram between one and four hours before exercise [4]. Include some protein and keep fat and fibre low so the meal feels easy to digest.

A plate of rice with chicken breast, or a turkey sandwich with fruit, can work well.

There is no narrow “window” that closes a few minutes after training. Protein is useful both before and after a workout, and the effect of exercise on muscle lasts at least 24 hours, although it gradually diminishes [1].

Make sure your next meal contains 20 to 40 g of protein [1] and some carbohydrate to replenish glycogen. Greek yoghurt with fruit and oats, or a tuna sandwich, are options.

A day of meals for building muscle

If you strength train in the afternoon, this example shows how to spread food across the day. We adjust portions to your appetite, schedule and training demands. You can divide your protein intake across several meals [1].

• Breakfast. Wholegrain toast with egg and tomato, plus fruit.
• Lunch. Rice with lentils, vegetables and olive oil; add yoghurt if you like.
• Pre-workout snack. A turkey sandwich and a piece of fruit, depending on how long you have before training [4].
• Dinner after training. Fish with potatoes and vegetables, or tofu with rice and vegetables.

These are examples of food combinations, without fixed calorie amounts. If you train in the morning, move the meals around your session.

Do you need any supplements?

No. The International Olympic Committee consensus on supplements concludes that most products aimed at athletes lack strong evidence [6]. It describes benefits for some products in specific circumstances [6]. Choosing one safely requires an individual assessment, especially if you compete.

Before taking a supplement, your doctor or dietitian should assess whether it makes sense for you. There is also a risk of products being contaminated with undeclared substances [6]. If you are under 18, do not take sports supplements. In any case, first look at what your meals already provide.

Can you build muscle and lose fat at the same time?

Yes, especially if you are new to strength training, returning after a break or starting with a higher body fat percentage. This is called body recomposition. It becomes slower after years of training, and alternating periods of moderate surplus with periods of gradual fat loss often works better.

If your priority is to lose fat without losing muscle, the deficit needs to be moderate. Eating too little for the amount you train is known as Relative Energy Deficiency in Sport (REDs). The International Olympic Committee consensus warns that, if sustained, it affects hormones, bone health and performance [7].

Keep protein intake high and strength training consistent, following the principles in our weight-loss diet guide.

Which mistakes do we see most often in consultations?

These are the four situations we see most often when someone trains but does not progress.

• Eating too little for fear of gaining fat. There is no surplus, so muscle gain stalls too.
• Copying a gym partner’s or social media user’s protein intake without considering your own weight or goal.
• Changing plans every few weeks because the scale has not moved. Muscle builds slowly, and changes become visible over months.
• Following food rules so rigidly that they take over your life and leave you without energy to train [7].

For general training and competition advice, see our sports nutrition guide. If you also play a team sport, our basketball diet guide shows how the approach can be adapted to a particular sport.