How to cut without losing muscle

What keeps your muscle

In a deficit your body looks for energy everywhere, muscle included. To make it take that energy from fat, you have to give it reasons to keep the muscle:

• Load — heavy training tells your body the muscle is needed.
• Protein — the material your muscle repairs itself with, even in a deficit.
• Pace — the gentler the deficit, the less you lose.

The review by Helms, Aragon and Fitschen (2014) on natural bodybuilding contest prep comes down to these three points. Sleep and stress matter too, but nothing saves you without these three.

How fast to lose weight

Helms et al. recommend losing 0.5–1% of bodyweight a week. For 80 kg that's 0.4–0.8 kg a week. The leaner you are, the closer to the bottom end: when there's little fat left, a fast cut eats into muscle more often.

You'll always want to go faster, especially in the first weeks. But the difference between a two-month and a three-month cut is a few weeks, while the strength you lose stays with you much longer.

How big a deficit

Start at 10–20% below maintenance: the calorie calculator works out both your maintenance and a cutting range. For someone with a maintenance of 2,700 kcal, that's about 2,150–2,450 kcal a day.

After that, the scale is in charge. Weigh yourself under the same conditions and compare weekly averages: if you're losing less than 0.5% a week for two or three weeks running, take away another 100–200 kcal. Faster than 1% — add some back. In the first week weight often drops faster because of water — don't panic and don't draw conclusions from it.

Keep lifting heavy

The most common mistake is switching to "light weights and high reps for definition". Definition comes from low body fat, not from reps. Light weights take away the very signal that keeps your muscle.

Keep your main lifts and working weights the same as on a bulk. You can cut volume a little — by 2–3 sets per muscle per week if your recovery suffers. The goal on a cut isn't records; it's holding on to what you have. If your weights hold steady, you're doing it right. How to progress in general is in the guide on progressive overload.

More protein

In a deficit, protein matters more than on a bulk. Helms et al. recommend 2.3–3.1 g per kg of lean mass; across total bodyweight, for a typical lifter, that's roughly 1.8–2.7 g per kg. The ISSN position stand (Jäger et al., 2017) also says higher protein in a deficit helps preserve muscle.

Bonus: protein is filling, which makes a deficit easier to stick to. Work out your range in the protein calculator with the "Cut" goal. Kidney disease — talk to a doctor first.

What happens to your strength

On a cut, strength usually holds or dips slightly — especially near the end, when there's little fat left. That's normal. What's not normal is your estimated max on the main lifts dropping week after week right from the start.

That's a sign the deficit is too big, protein is too low or you're short on sleep. Add 100–200 kcal and check your protein. I see it in your log: I work out your estimated max after every workout, with your bodyweight trend right next to it.

Cardio and steps

Cardio helps with the deficit but doesn't replace lifting. The simplest option is steps: walking barely gets in the way of recovery. Hard leg-heavy cardio the day before squats or deadlifts steals strength from the bar.

The order goes: lifting first, then food, then steps, and cardio only if that's not enough. If there's so much cardio that your weights drop, it's not a cut anymore — it's marathon prep.

Keep your steps steady from day to day: if you start walking less, you burn less, and the scale will show it a week or two later.

Common questions

Can I lose fat and build muscle at the same time? Beginners, people coming back after a break and those with plenty of fat — often yes. People who've trained for years — slowly, which is why it's easier to alternate bulking and cutting.

How long should a cut last? Until you reach your goal — usually 8–16 weeks. Longer without a break is hard on your head and your body: you can spend a couple of weeks at maintenance and then continue.

How do I know it's time to stop? You've hit your goal in the mirror, or your strength keeps dropping despite every adjustment. Then ease back up to maintenance — see how to bulk after a cut.

Read next

• Calories per day
• Protein per day
• How many calories you need to build muscle
• Progressive overload