Macros for Cutting: How to Set Your Numbers

Step 1: Set your calories

Start from your maintenance calories, the amount that keeps your weight steady. Estimate it with the calculator, then confirm it with two to three weeks of tracked eating and daily weigh-ins. How to calculate your maintenance calories walks through it.

Then choose a rate of loss. In their 2014 evidence-based recommendations for natural bodybuilders, Helms and colleagues advise losing about 0.5 to 1% of your body weight a week to hold on to muscle, and note that, in theory, a deficit of about 500 calories a day loses about 0.45 kg (1 lb) of fat a week. The leaner you are, the closer to 0.5% you should be.

Step 2: Set protein

Protein comes first because it protects muscle in a deficit and helps keep hunger down.

• A 2018 meta-analysis by Morton and colleagues (British Journal of Sports Medicine) found that the benefit of protein for muscle levels off at about 1.6 g per kg of body weight a day, with 2.2 g/kg covering most people.
• On a cut, aim toward the top. Helms and colleagues suggest 2.3 to 3.1 g per kg of lean body mass for lean lifters dieting hard.
• Spread it out. The International Society of Sports Nutrition suggests 20 to 40 g per meal.

If you are carrying a lot of body fat, base your protein on your goal weight rather than your current weight, or the number comes out unrealistically high. How much protein you need covers food sources, or use the protein calculator.

Step 3: Set fat

Helms and colleagues suggest getting 15 to 30% of your calories from fat, using the lower end if more fat would squeeze protein or carbohydrate below where you want them.

Do not take fat to the floor for months just to fit in more carbohydrate. A 2021 meta-analysis of six trials by Whittaker and Wu found that low-fat diets lowered testosterone in men, though the authors say more well-designed trials are needed to confirm it. You also need some fat: the British Dietetic Association notes that it helps you absorb vitamins A, D, E and K, and supplies essential fatty acids.

Step 4: Let carbohydrate fill the rest

Whatever calories are left after protein and fat go to carbohydrate. It is the main fuel for hard training, so on a cut it is worth keeping as high as your calories allow. Helms and colleagues even suggest that, once a competitor is at or near stage leanness, adding a little carbohydrate back may help protect performance and muscle.

Choose mostly high-fibre, filling carbohydrates: potatoes, oats, rice, beans, lentils, wholegrain bread, fruit and vegetables. The NHS recommends 30 g of fibre a day for adults, and most people manage only about 20 g.

A worked example

Two people, each aiming to lose about 0.5% of their body weight a week.

	Person A	Person B
Body weight	80 kg (176 lb)	65 kg (143 lb)
Maintenance (from their own data)	2,750	2,100
Target loss a week	0.4 kg (0.9 lb)	about 0.33 kg (0.7 lb)
Deficit a day	about 450	about 350
Calories	2,300	1,750
Protein (about 2.2 g/kg)	175 g = 700 calories	145 g = 580 calories
Fat (about 25%)	65 g = 585 calories	50 g = 450 calories
Carbohydrate (the rest)	255 g = 1,020 calories	180 g = 720 calories

How Person A's numbers were worked out:

1. Calories: 2,750 − 450 = 2,300.
2. Protein: 80 kg × 2.2 = 176 g, rounded to 175 g. 175 × 4 = 700 calories.
3. Fat: 25% of 2,300 is 575 calories; 575 ÷ 9 ≈ 64 g, rounded to 65 g (585 calories).
4. Carbohydrate: 2,300 − 700 − 585 = 1,015 calories; 1,015 ÷ 4 ≈ 254 g, rounded to 255 g.

Totals land within a few calories of the target because of rounding, which is fine. These are example numbers, not targets for you: your own maintenance and body weight decide yours.

How to adjust your macros as you go

Your numbers will not stay right for the whole cut.

Your maintenance falls as you lose weight. A 2011 paper in The Lancet by Hall and colleagues gives a rule of thumb for an average overweight adult: each 24 calories a day of intake is worth about 1 kg (2.2 lb) of eventual body weight. Turned around, after losing 5 kg (11 lb), your maintenance is likely about 120 calories a day lower. Helms and colleagues also point out that calories need adjusting as body mass falls.

There is no tested rule for exactly when to change things, so this is common coaching practice:

• On target? Change nothing.
• Weekly average flat for two to three weeks, with honest tracking and steady steps? Take a small amount out of carbohydrate or fat. For scale, 25 g of carbohydrate is 100 calories and 10 g of fat is 90. Keep protein where it is.
• Training suffering? Move some calories from fat to carbohydrate, keeping the total the same.
• Losing faster than about 1% a week, or feeling awful? Add a little back, usually as carbohydrate.
• Hungry all the time? Keep protein high, lean on high-volume foods and check your sleep. How to stop feeling hungry on a diet covers what the research shows.

Make one change at a time, then give it two weeks before judging it.

How exact do you need to be?

Calories and protein matter most, so get those close every day. Fat and carbohydrate can move around within your calories, depending on what you eat that day and how you train. Weigh foods for the first few weeks so you learn what a real portion looks like, and log cooking oils, sauces and drinks, which are easy to forget.

If you have a health condition such as diabetes or kidney disease, or take regular medication, speak to your doctor before changing your diet.

How coaching helps

The first set of macros is the easy bit. Knowing when to change them, and which one, is where most people get stuck. With one-to-one coaching from CoachAk, your daily calories, macros, step target and any cardio sit in a private app and are updated as your body responds. Each weekly check-in covers your weight, training and nutrition adherence, steps, sleep, energy, hunger and stress, and your coach replies with written feedback on what went well, what changes next week and why.

If you want your cutting macros set and adjusted for you, apply for coaching.