Macro split for muscle gain, cutting and maintenance

The short answer: protein first, carbs last

A percentage split asks you to choose three numbers that must add up to 100. A better order is to choose them one at a time, because they are not equally well supported by evidence. Protein has a target in grams per kilogram of body weight. Fat has a sensible range as a share of calories. Carbohydrate has no minimum worth fighting over, so it takes whatever calories are left. The rule we used for every goal below:

• Calories: set by the goal, from a maintenance estimate (estimated 2,700 for our example man), then above it for muscle gain or below it for cutting.
• Protein: 1.6 g per kg for maintenance and muscle gain, 2.0 g per kg for cutting (128 g and 160 g for an 80 kg man, estimated).
• Fat: 25% of calories, which is 61 g, 75 g or 83 g depending on the calorie level (estimated).
• Carbs: everything else, divided by 4 calories per gram.

The same arithmetic is laid out step by step in our guide to calculating macros. Here we change only the goal and watch what moves.

Three goals for one 80 kg man

Our example is a 35-year-old man, 180 cm and 80 kg (5 ft 11 in, 176 lb). The Mifflin-St Jeor equation, derived from 498 healthy adults (Mifflin and colleagues, 1990), gives him 10 × 80 + 6.25 × 180 − 5 × 35 + 5 = 1,755 calories at rest, and 2,720 at a multiplier of 1.55, which we round to 2,700 as his maintenance estimate. That is an estimate that could be off by a tenth either way, so a real person would adjust it from a few weeks of experience.

From there we picked the steps ourselves: 300 calories above maintenance for muscle gain and 500 below for cutting. These are illustrative choices, not recommendations, and a professional may suggest others for you. Protein is higher for cutting for a reason covered in the next section.

All three sit inside the National Academies' acceptable macronutrient distribution ranges for adults, 10% to 35% of calories from protein, 20% to 35% from fat and 45% to 65% from carbohydrate (National Academies, 2024). Cutting is the tight one: carbs land at 46%, barely above the 45% floor, because 29% of calories go to protein.

Why protein moves with the goal and carbs take the rest

Two sources set the protein numbers. A meta-analysis of 49 trials and 1,863 healthy adults found that, in people doing resistance training, protein supplementation stopped producing extra fat-free mass beyond a total intake of about 1.62 g per kg a day (Morton and colleagues, 2018). The International Society of Sports Nutrition goes a little wider: 1.4 to 2.0 g per kg a day is enough for most exercising people who want to build or keep muscle (Jäger and colleagues, 2017). So 1.6 g per kg for maintenance and muscle gain sits inside the range, and 2.0 g per kg for cutting sits at the top of it.

Why the top for cutting? When you eat below maintenance, protein is the number people raise to protect lean mass. The same position stand says higher intakes, 2.3 to 3.1 g per kg, may be needed to maximize the retention of lean body mass in resistance-trained people during hypocaloric periods. We stayed at 2.0 for an example man whose training we do not know. If you are lean and train hard, ask a professional: 2.3 g per kg would be 184 g for this man, a third of his 2,200 calories (estimated).

Higher protein intakes (2.3-3.1 g/kg/d) may be needed to maximize the retention of lean body mass in resistance-trained subjects during hypocaloric periods.

For fat, a review of preparation for natural bodybuilding contests suggests most competitors respond best to 15% to 30% of calories from fat, with the remainder as carbohydrate (Helms and colleagues, 2014). That is advice for people preparing for a stage, so we read it as a range to stay inside, not a target to chase. We chose 25%, the middle of the range, for all three days. It keeps the arithmetic simple and leaves room for oil, nuts and the fat that comes inside eggs and fish.

Why a percentage split can mislead you

Popular splits such as 40% carbs, 30% protein and 30% fat, or 40% carbs, 40% protein and 20% fat, look neutral. They are not, because a fixed share of calories means protein in grams rises and falls with calories. The table divides the protein those splits imply by the body weight of our 80 kg man.

At 2,200 calories a 30% split happens to land close to our number. At 3,000 it asks for 225 g, which is 2.8 g per kg, well above the 1.62 g per kg point where Morton and colleagues saw no further gain in fat-free mass, and above the 1.4 to 2.0 range the ISSN calls sufficient for most people (estimated). Nothing says that is harmful for a healthy adult, and nothing in these sources says it helps. It does mean you are buying more protein, and giving up carbohydrate calories, for no reason a percentage can explain. Divide your protein grams by your weight in kilograms before you copy a split.

The same foods, three portions: what the plate looks like

Targets are only arithmetic. To see them on a plate, we composed one day for each goal from the same 16 foods, changing only the portions. Breakfast is oats, milk, banana and an egg; lunch is chicken, rice and broccoli; the snacks are yogurt, blueberries, an apple and, on the larger days, bread with peanut butter; dinner is salmon, a baked potato and spinach. Olive oil is split between lunch and dinner. Portions are in 5 to 50 g steps, chosen by a small search that minimizes the distance to the protein, fat and carb targets, then checked line by line. It is one example, not a recommendation to eat it.

Look at the chicken row. The muscle gain day has the least chicken of the three, 50 g against 150 g on the cutting day. Protein barely changes between the days, so the chicken, salmon and yogurt that carry it on the cutting day are replaced on the larger days by more rice, potato, oats and bread, which carry the calories. This is the practical meaning of protein first: you hold a protein anchor and let carbohydrate flex.

What each day adds up to

Every food was multiplied by its USDA value per 100 g and the lines summed. The result, against the targets:

All three calorie totals land within 2% of their targets, and carbs and fat within about 3 g. The loose one is protein on the muscle gain day: 136.8 g is 8.8 g, about 7%, above 128 g, because there was no smaller step that kept the day looking like ordinary food (estimated). That is 1.71 g per kg, still inside the ISSN range.

Now compare the columns. From the cutting day to the muscle gain day, carbs rise by about 180 g, fat by about 21 g, and protein falls by about 21 g (estimated). On the standard factors of 4 calories per gram for carbs and 9 for fat, carbs account for about 720 calories of the difference and fat for about 185, while protein takes back about 85. The USDA energy values for the same foods differ by 791 calories between the two days, a few percent less than that tally, because 4 and 9 are averages and fiber sits inside the carbs (estimated). The point holds either way: when the goal changes, the carbohydrate line does most of the moving, which is why a split that fixes protein and fat first is easier to adjust than one that fixes three percentages.

Cutting, maintenance and muscle gain in one table

Here is the whole picture as the three splits an 80 kg man would be working to, rounded from the targets above (estimated).

Notice that protein as a percentage is highest when you eat least. That is not a contradiction: 160 g is a larger share of 2,200 calories than 128 g is of 3,000. If a calculator shows you a muscle gain split with less protein than a cutting split, it may be doing the same arithmetic.

How to pick yours

Start from your own numbers, not from ours. Estimate your maintenance calories (the macro calculator does it in a minute), multiply your weight in kilograms by 1.6 for protein, take about a quarter of calories as fat, and give the rest to carbs. If you are cutting, move protein up toward 2.0 g per kg and watch that carbs stay at 45% or more; if you are aiming for muscle gain, add calories as carbs.

Then treat it as a hypothesis. Follow it for two or three weeks and watch your training, your hunger, your energy and the trend of your weight, not a single morning. If it does not fit, change the calories first and keep the method. Day-to-day precision matters less than the weekly pattern, and a day that is 5% off is an ordinary day. For the question of whether to count macros at all or just calories, see macros or calories: which to count, and for how much protein a day, how much protein per day.

A practical note on weighing: the grams in our tables are cooked or dry weights as labeled, because 100 g of cooked white rice is 130 calories while 100 g of dry oats is 389 (estimated). Entering a cooked weight against a dry value, or the reverse, can move a meal by hundreds of calories. Our guide to counting macros raw or cooked explains how to keep one convention.

When to ask a professional instead

This is general information, not medical advice. If you have diabetes, kidney disease or a food allergy, are pregnant or breastfeeding, are under 18, have or have had an eating disorder, or take medication that affects your appetite or blood sugar, ask a doctor or a registered dietitian for your numbers before you follow any macro split. If a professional has given you calorie or macro targets, use theirs. Eating well below maintenance is a decision to make with advice, and counting grams can become an unhealthy habit for some people, so stop and talk to someone if it causes worry about food.

Doing this every week without the spreadsheet

This part is written by the team behind MacroRecipe, so read it with that in mind. The method above is easy to do once and tedious to repeat: each day needed 16 lines and a search to hit the targets, and a week of different days is more than 100. If you enjoy the arithmetic, a spreadsheet and a kitchen scale are enough, and USDA FoodData Central is where to look values up.

MacroRecipe does the matching step instead. It plans your week of menus around your macros and the goal you choose, from dishes you pick, with ingredient data from USDA and CIQUAL (ANSES). It sizes portions toward your estimated calorie and protein targets, and when you swap a dish the portions and the grocery list follow, with quantities added up across recipes.

Who it isn't for: MacroRecipe runs on iPhone only, not on Android. It has no barcode scanner, no food database to search and no complete daily food diary, though a photo scan of a meal eaten elsewhere comes with the subscription. You can preview your first menu for free, after which it is a paid subscription. If you would rather log everything you eat, see our MacroFactor alternatives guide.

How we calculated

Every food line is the portion in grams multiplied by its value per 100 g in USDA FoodData Central, SR Legacy, read from the April 2018 CSV downloaded from the USDA dataset page on 2026-10-31. Calories are USDA's own energy values, not recomputed. Carbohydrate is by difference, as USDA lists it. We used one matching food per item and did not mix brands.

• Equation. Mifflin-St Jeor in its simplified form, times 1.55, rounded to the nearest 50 calories (estimated 2,720 to 2,700).
• Targets. Protein by body weight, fat at 25% of calories, carbs the rest at 4 calories per gram; the calorie steps of plus 300 and minus 500 are our illustrative choice.
• Portions. The day for each goal was fitted from the same 16 foods in steps of 5 to 50 g, to be close to the three gram targets, then summed line by line. The fit is ours, so other days are possible.
• Not tested. We did not measure anyone's energy use or results, and the days were not cooked and weighed in a kitchen. This is a recount of composed menus, not a trial.

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