14 June 2026

How much protein do you actually need on a cut?

Search this and you'll get answers between 0.8 and 2.2 grams per kilogram, quoted with equal confidence. The spread isn't because nobody knows — it's because the recommendations answer different questions. Here's what protein is actually doing while you're in a deficit, and the one number worth aiming for.

The deficit changes the job protein does

When you eat at maintenance, protein mostly just builds and repairs as normal. When you eat below maintenance, your body needs to find the missing energy somewhere — and it can pull that energy from fat or from muscle. Protein is the lever that biases it toward fat.

That's the whole point of a higher protein intake on a cut: not to "build muscle" in a deficit (hard to do), but to protect the muscle you already have while you lose fat. Lose weight on too little protein and a meaningful chunk of what comes off is lean tissue — which is exactly the tissue keeping your metabolism up and your shape looking like progress.

Why the 0.8 g/kg number is a trap

The figure you'll see quoted as the "official" requirement — around 0.8 g per kg — is the amount needed to prevent deficiency in a sedentary person eating at maintenance. It's a floor for not getting sick, not a target for keeping muscle while dieting. Using it on a cut is like setting your thermostat to "won't freeze to death" and calling it comfortable.

The number that actually works

For someone losing fat, the well-supported range is roughly 1.6 to 2.2 g of protein per kg of body weight per day. The honest summary of the research: more than about 1.6 g/kg buys you very little extra muscle protection, and going to the top of the range mostly helps with appetite rather than physiology.

If you prefer pounds, the lazy-but-fine version is "about one gram per pound of goal weight." It slightly overshoots, but protein is the one macro where erring high is harmless for most people.

The underrated benefit: it keeps you full

Protein is the most satiating macro by a wide margin. On a deficit — when you're hungry by design — hitting your protein first tends to blunt the appetite that makes people cave. Two people eating the same calories can have completely different experiences of a cut depending on whether those calories were mostly protein or mostly snacks. The hunger isn't willpower; it's macronutrient composition.

Where carbs and fat fit

Once protein is set, the rest is preference. Carbs and fat are interchangeable for fat loss as long as total calories stay in a deficit — there's no magic ratio. Keep fat high enough for hormones and satiety (a common floor is around 0.5 g/kg), and let carbs fill whatever calories remain. Train hard? Lean toward carbs. Don't? It genuinely doesn't matter much.

The takeaway

On a cut, protein isn't about building — it's about defending. Set it around 1.8 g per kg of goal weight, hit that number most days, and stop agonising over the carb-to-fat split. The deficit drives the fat loss; the protein decides how much of what you lose is fat versus muscle.