How much protein when you are cutting

17 August 2026·7 min read

Most macro arguments are not worth having. The split between carbohydrate and fat matters far less than people think, and the best split is largely the one you can live with for as long as the diet lasts. Protein is the exception. It is the one macro worth being deliberate about while you are losing weight, and it is worth it for three separate reasons rather than one.

Why it matters more in a deficit

When you eat less than you burn, your body makes up the difference from stored energy. You would very much like that stored energy to be fat. Some of it can be lean tissue instead, and how much depends heavily on two things: whether you are giving your body a reason to keep its muscle, which is resistance training, and whether you are giving it the raw material, which is protein.

This is not vanity, or not only vanity. Muscle is metabolically active tissue, so losing it lowers the very burn rate you are trying to preserve, which makes every later stage of the cut harder than it needed to be. It also changes what the result looks like: two people can lose the same 10 kg and end up looking completely different depending on what that 10 kg was made of.

The second benefit is more immediate. Protein is the most satiating macronutrient per calorie, and in a deficit hunger is the main reason plans fail. A meal built around protein keeps you full noticeably longer than the same calories of carbohydrate or fat, which means the deficit costs you less willpower per day. Over three months, that compounds into the only thing that actually matters: whether you are still doing it.

The third is smaller but real. Digesting food costs energy, and protein costs the most: commonly cited figures put roughly 20 to 30 per cent of protein calories back into the cost of processing it, against about 5 to 10 per cent for carbohydrate and very little for fat. It is not a licence to ignore the arithmetic, but it does mean the calories on a protein label are worth slightly less to you than the same calories from anything else.

Roughly how much

The commonly cited range for someone losing fat while training is around 1.6 to 2.2 grams per kilogram of bodyweight per day. For most people most of the time, landing anywhere in that band is fine, and the difference between 1.8 and 2.1 is not worth a single minute of agonising.

Two practical adjustments to that table:

• If you carry a lot of fat, scaling to your total bodyweight overshoots. Body fat does not need feeding with protein. Using a target weight, or a lean-mass estimate, gives a more sensible figure: a 120 kg person aiming for 90 is better served by the 90 kg row than by a 264 gram target they will never hit.
• The steeper the deficit, and the leaner you already are, the more the top of the band earns its place. That combination is when muscle is genuinely at risk. A gentle deficit at a higher starting bodyweight can sit comfortably at the bottom of the range.

For a 90 kg person, then, roughly 145 to 200 grams a day. That is considerably more than most people eat without paying attention, and it is the single most useful thing to actually track.

What that looks like in food

Targets in grams are abstract until you see the portions. These are approximate, and labels vary, but they are close enough to plan a day with.

Read that table and the shape of a 150 gram day becomes obvious: three anchored meals of 40 grams each, plus a yoghurt or a shake, and you are there without anything unusual happening. Read it a second time and you will also notice why people miss the target. Nothing on the list is a snack food, and the foods most people reach for between meals contribute almost nothing.

Hitting it without it becoming a project

• Anchor each meal. Decide the protein first and build the rest of the plate around it, rather than assembling a meal and hoping. Three meals at 40 grams each does most of the work before you have thought about anything else.
• Breakfast is where it is usually lost. Cereal, toast and fruit is a near zero protein start, and it leaves an unrealistic amount to make up after lunch. Eggs, Greek yoghurt or a shake changes the whole day, and it is one decision rather than a hundred.
• Keep dense options within reach. Greek yoghurt, cottage cheese, eggs, tinned fish, cooked chicken, tofu, milk, whey. Convenience is the deciding factor on a bad day, and bad days are the ones that decide the average.
• Front-load if evenings are unpredictable. If dinner is often out of your hands, get 100 grams in before you leave work and the evening stops mattering.
• Do not fear the timing question. Total daily intake matters far more than distributing it perfectly across the day, and the anabolic window has been considerably overstated. Spreading protein across three or four meals is a reasonable default, not a rule to be anxious about.
• Plant-based works, it just needs a plan. Tofu, tempeh, soy milk, seitan, lentils, beans and a soy or blended protein powder will get you there. It takes more deliberate assembly than a chicken breast, so it rewards deciding in advance rather than improvising.

What Cut does about it

Cut sets a protein target from your bodyweight alongside your calorie target, and shows both as you log. The macro breakdown flags when a day is running protein-light while there is still time to do something about it, rather than reporting it as a failure at midnight when the information is useless.

It also keeps a fat floor rather than letting the arithmetic drive fat towards zero, and it does not moralise about carbohydrate. Protein is the deliberate one. The rest is preference, and preference is what you can actually sustain.

None of this is medical advice, and individual needs vary. If you have kidney disease or another condition that affects how much protein you should eat, that is a conversation for your doctor rather than for an app.