Lose 0.5–1% of body weight per week, no faster. Eat 2.3–3.1 g of protein per kg of fat-free mass. Keep the heavy lifts and cut volume, not load. Sleep seven-plus hours. Athletes losing 0.7% per week gained lean mass and strength; those losing 1.4% did not. Androgens protect muscle in a deficit but change none of these rules.
- 0.7% body weight per week: lean mass +2.1%, 1RM up. 1.4% per week: lean mass unchanged, less strength gain. Same fat loss (Garthe et al., 2011, 24 elite athletes).
- Protein for lean, trained people in a deficit: 2.3–3.1 g per kg of fat-free mass per day, higher end when leaner (Helms et al., 2014).
- Fat at 15–30% of calories, the rest carbohydrate around training (Helms, Aragon, Fitschen 2014).
- Load on the bar is the muscle-retention signal; switching to light high-rep work removes it.
- Short sleep shifts weight loss toward muscle and away from fat.
The four rules
| Rule | Number | Why |
|---|---|---|
| Rate of loss | 0.5–1% of body weight per week | Faster costs muscle and strength (Garthe 2011) |
| Protein | 2.3–3.1 g per kg fat-free mass | Amino acids from food, not from muscle (Helms 2014) |
| Training | Same loads, 20–30% fewer sets | Tension keeps muscle; recovery is lower in a deficit |
| Sleep | 7–9 hours | Short sleep shifts loss from fat to muscle |
Rate
Garthe and colleagues randomised 24 elite athletes to lose 0.7% or 1.4% of body weight per week with the same lifting programme. Slow group: lean mass up 2.1%, one-rep max up. Fast group: no lean gain, less strength. Fat loss the same. Weigh daily, judge by the weekly average, and if it drops faster than 1%, eat more. The calorie deficit sets the rate; nothing else does.
Protein
Set it first. 2.3–3.1 g per kg of fat-free mass, not body weight, higher end as you get leaner. Example: 90 kg at 15% fat is ~76 kg fat-free, so 175–235 g per day. Three to five meals with a real portion each.
Carbs and fat
Fat 15–30% of calories for hormone production. The rest carbohydrate, placed around training. Cutting carbs to zero is the most common cause of strength loss on a cut.
Training
Keep the compound lifts and the weight on the bar. Drop total sets by about a quarter. Progress is not the goal; holding your lifts while losing fat is the win. Cardio: 2–4 moderate sessions a week, enough for heart and deficit, not enough to eat recovery.
Mistakes that cost muscle
- Big deficit in week one. Start moderate, cut further only when progress stalls.
- Dropping protein with everything else.
- Two hours of daily cardio.
- Judging by the scale alone: water hides fat loss for a week or more. Use waist, photos, gym numbers.
- Carbs to zero.
On androgens
They blunt muscle loss in a deficit, which is why they are used before competition. They do not speed fat loss, replace protein or fix training. Same rules, better retention. Whether and how to use them is a decision with your physician, with bloodwork on the table.
Frequently asked questions
How big a deficit?
Whatever produces 0.5–1% of body weight lost per week on the weekly average. For most, a few hundred calories below maintenance. Faster means muscle.
How much protein?
2.3–3.1 g per kg of fat-free mass. A 90 kg lifter at 15% fat has ~76 kg fat-free mass: 175–235 g per day, in 3–5 meals.
How much cardio?
Enough to help the deficit and the heart, not enough to wreck recovery: 2–4 moderate sessions a week is typical. Create most of the deficit with food.
Will I lose strength?
Little, with a moderate deficit, high protein and heavy training. A sharp early drop means the deficit is too aggressive.
What changes on anabolic steroids?
Muscle loss in the deficit is much smaller, which is why they are used before competition. Rate of fat loss, protein needs and training rules do not change.
Sources
- Garthe I et al. Effect of two different weight-loss rates on body composition and strength and power-related performance in elite athletes. IJSNEM, 2011.
- Helms ER et al. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes. IJSNEM, 2014.
- Helms ER, Aragon AA, Fitschen PJ. Evidence-based recommendations for natural bodybuilding contest preparation: nutrition and supplementation. JISSN, 2014.
- Morton RW et al. Protein supplementation and resistance training-induced gains: systematic review and meta-analysis. BJSM, 2018.