Lose fat without losing muscle

1. Not too fast

The bigger the deficit, the more muscle goes with the fat. A good guide for people who lift: 0.5 to 1 % of bodyweight a week. At 80 kg that is 400 to 800 g.

In a study with elite athletes, one group lost 0.7 % a week, the other 1.4 %. Both lost the same in the end. The slower group also gained 2.1 % lean mass, the faster one did not.

What that means in calories

Fat tissue stores about 7,700 kcal per kilogram. So 400 to 800 g a week is roughly 450 to 850 kcal a day below your maintenance calories. A meta-analysis advises anyone who wants to keep muscle while losing weight to cut no more than about 500 kcal a day. So start at the low end. Whether it fits shows in your 7-day average after two to three weeks, not in a calculator.

2. More protein than usual

In a deficit you need more. In a four-week study with a large deficit and hard training, two groups ate 1.2 or 2.4 g of protein per kg. The 2.4 g group gained muscle despite the deficit and lost more fat.

A good range for most people: 1.8 to 2.4 g per kg of bodyweight. The protein calculator shows your number.

3. Stay heavy, adjust the volume

Training is the signal that tells the body to keep its muscle. Drop it and the body breaks muscle down. So keep the weight on the bar as high as you can. When recovery slips, take away a set rather than weight.

Your main lifts are the gauge. If bench, squat and deadlift hold steady, that is a good sign. If they drop clearly over two to three weeks, the deficit is probably too big.

4. Enough sleep

In one study people ate the same reduced amount for two weeks, once with 8.5 hours of sleep and once with 5.5. On short sleep they lost 55 % less fat and 60 % more lean mass. Sleep is part of the plan.

How you know it works

• The 7-day average of your bodyweight drops by 0.5 to 1 % a week.
• Your strength in the main lifts holds.
• Your waist gets smaller.

Single days say little. Water, salt and digestion move the scale by 1 to 2 kg. More in Why the scale jumps after the weekend.

What to avoid

• Slashing calories. The coach in Trilluminati never plans below 1,200 kcal a day, and for most people who lift even that is too little.
• Swapping lifting for cardio. Cardio helps with the deficit but does not replace the signal for your muscles.
• Deciding by the scale every day. The direction over weeks counts, not Monday.