Eating for muscle gain: a complete guide with numbers

You are eating more than you used to, training four times a week, and the scale has read the same number for three weeks. Or the opposite is happening — you are putting on a kilogram a week and the only thing clearly growing is your waist. Both problems come from the same place: the food is being guessed at and the progress is not being measured.

Building muscle is slow work with narrow margins. The gap between a surplus that builds tissue and a surplus that builds fat is often 200 to 300 calories a day. So this guide runs on numbers, one step at a time.

Step 1: find out where you are starting

Before you add anything, you need a baseline — how much you eat now, and what your weight does at that intake. Ten to fourteen days is enough. Weigh yourself every morning, after the loo and before breakfast, and write it down.

Judge by the weekly average, never a single day. Daily swings of 0.5 to 1.5 kg are normal and come from water, salt and gut contents, and the weekly gain you are aiming for is smaller than that swing.

If your average after two weeks matches where you started, that intake is your maintenance. If you have no patience for tracking, a rough figure is 30 to 35 calories per kilogram of bodyweight for someone training three to five times a week in a desk job. For an 80 kg person that is roughly 2400 to 2800 calories. The estimate can be 300 calories out in either direction, so the scale still has the final say. The full method, with the formulas, is in our guide on working out your calories and macros step by step.

Step 2: how big a surplus, and how fast

A surplus of 10 to 15 per cent above maintenance covers nearly everyone. In plain numbers, 250 to 400 calories a day. A bigger surplus does not speed up muscle growth, because that rate is biologically capped. It only speeds up fat gain.

Track the rate as a percentage of bodyweight per week:

• First year of proper training: 0.25 to 0.5 per cent a week. At 80 kg that is 200 to 400 grams.
• After two or three years: around 0.25 per cent, so up to 200 grams a week at the same bodyweight.
• Long-term trained lifters: progress is measured in months rather than weeks, and some of the gain will be fat however careful you are.

Gaining faster than that? Take off 150 to 200 calories. Average flat for three weeks running? Add the same amount. Change nothing until those three weeks have passed, or you are adjusting to noise rather than signal.

Step 3: protein

1.6 to 2.2 grams per kilogram of bodyweight per day. Above that ceiling the evidence shows no further benefit for growth, however hard the marketing pushes. For an 80 kg lifter that is 130 to 175 grams.

Spread it over three to five meals, roughly 0.4 grams per kilogram in each one, which lands at 30 to 40 grams for most people. One meal with 150 grams of protein and three without is not the same stimulus as an even spread.

Sources that do the heavy lifting, per 100 grams: chicken breast 28 to 30 g cooked, beef around 26 g, tinned tuna around 25 g, Greek yoghurt 9 to 10 g, cottage cheese 11 to 12 g, cooked lentils around 9 g. An egg gives about 6 g. If your daily target looks out of reach, put a protein source at every meal before you start counting anything else.

Step 4: fat and carbohydrate

Set fat first, because it has a floor: 0.8 to 1 gram per kilogram, or 20 to 30 per cent of total calories. Below that most people simply feel worse, and there is nothing to gain from it.

Whatever calories remain go to carbohydrate, which usually works out at 4 to 6 grams per kilogram. That is the fuel for hard sets, and the main reason training feels sharper when there is enough of it.

A worked example at 80 kg and 2900 calories: 160 g protein is 640 calories, 75 g fat is 675 calories, and the remaining 1585 calories are carbohydrate — about 395 grams.

Step 5: the food that fills those numbers

Take roughly 80 per cent of your calories from food that carries micronutrients too: meat, fish, eggs, dairy, rice, potatoes, pasta, oats, pulses, fruit, vegetables, nuts, olive oil. The rest can be whatever you fancy.

When you are gaining, the sticking point is rarely quality — it is volume. If 3000 calories feels impossible, cut back the salad and raw veg alongside main meals, cook with oil rather than steaming, and lean on calories that go down easily: milk, nuts, peanut butter, honey, dried fruit. Fresh fruit is a cheap way to add 80 to 150 calories without filling you up, and we have broken down exactly what a single portion carries using the peach as an example.

Step 6: timing around training

A meal with protein and carbohydrate one to three hours before you train, and another within a few hours afterwards, covers everything that matters. The thirty-minute window after a session does not exist in the form it gets sold: if you ate beforehand, those amino acids are still circulating.

In practice, 30 to 40 grams of protein and 60 to 100 grams of carbohydrate before, and something similar after. If you train early and cannot face food, move one meal closer to the session and leave it at that.

Longer, sweatier sessions need more fluid and more sodium than most people assume, especially in summer. How much salt and potassium you actually need, and how to cover it from ordinary food, is set out in our piece on electrolytes from everyday meals.

Step 7: no training, no mass

A calorie surplus does not build muscle. It supplies the material. The signal comes from strength training: roughly 10 to 20 hard sets per muscle group per week, reps anywhere from 5 to 30 taken close to failure, and progression you can see in the numbers month on month.

If your working weights on the squat, press and row have not shifted in three months, the problem is not your macros. Fix the training first, then the plate.

Step 8: what to track

• Morning weight every day, judged as a weekly average.
• Waist at navel height, once a week. If it is growing faster than your chest and arms, the surplus is too big.
• Working weights and reps on three or four main lifts.
• Photos once a month, same time of day and same lighting.

The most common mistakes

An 800 calorie surplus because it is quicker. It is not quicker. The rate of growth is capped by biology, not by calories, and everything above the cap becomes fat you will spend months removing.

Weighing once a week, at a different time each time. A single reading tells you nothing, because the daily swing is larger than the weekly gain.

Protein maxed out, carbohydrate squeezed to nothing. A habit people carry over from dieting. The result is flat sessions and the feeling that nothing is moving.

Drinking calories instead of eating meals. A 1200 calorie shake fixes the number, kills your appetite for hours and leaves you short on fibre.

Cutting out every bit of movement outside the gym. People stop walking so they do not burn anything, then lose both their conditioning and their appetite. Keeping the steps and eating a bit more is the better trade — how much they actually shift the balance is covered in our piece on walking and daily step counts.

A new plan every ten days. Nothing runs long enough to produce data you could make a decision from.

When to see a doctor

Book an appointment if you are losing weight without meaning to, if a higher intake brings persistent stomach pain, diarrhoea or constipation, if you have diagnosed kidney or liver disease and are planning a high protein intake, or if food, weighing and counting start taking up a disproportionate share of your day.

If you take medication for your thyroid, diabetes or blood pressure, a change in bodyweight and intake can call for a dose adjustment. That decision belongs to your doctor.

Common questions

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

Reliably, only in three situations: a complete beginner, someone returning after a long layoff, and someone carrying a higher body fat percentage. In those cases strength training plus enough protein works even at maintenance. If you have trained for three years and are already lean, you have to pick a direction.

Do I need protein powder?

No, but it helps when hitting 160 grams from whole food alone means too much cooking. It is food in a more convenient form, not a supplement with special properties. Among supplements, creatine monohydrate has the strongest evidence for strength and size, at 3 to 5 grams a day, with no loading phase needed.

How many meals a day?

Three to five. Below three it is hard to spread protein evenly and fit the calories in; above five there is no extra benefit unless smaller meals simply sit better with you.

When should I stop the gaining phase?

When your waist is five to seven centimetres up on where you started, when you feel sluggish, and when sessions start dragging for no obvious reason. That is the point to switch to a cut, and the same arithmetic runs in reverse — the figures are in our article on the calorie deficit.

The short version

• Spend two weeks tracking weight and intake so you know your maintenance.
• Add 250 to 400 calories and aim for 0.25 to 0.5 per cent of bodyweight a week.
• Protein 1.6 to 2.2 g/kg, fat 0.8 to 1 g/kg, carbohydrate takes the remainder.
• Adjust only after three flat weeks, and only by 150 to 200 calories.
• Track weight, waist and working weights. If strength is not rising, fix the training before the diet.