The -20% rule
To lose fat, you eat below maintenance. The sweet spot for most guys:
Cutting calories = maintenance x 0.80 (a 20% deficit)
Example: maintenance 2,550 -> 2,550 x 0.80 = ~2,040 calories to cut.
Why 20%? It's aggressive enough to see weekly progress but moderate enough that you keep your strength, sleep, and muscle. Bigger deficits (30%+) burn out fast and eat muscle. Smaller ones (10%) are fine but slow.
Recalculate your macros for the cut
Protein goes up (high end, 1.0 g/lb — it protects muscle and keeps you full). Fat holds at its floor. Carbs absorb the cut.
| Macro | Target | Grams | Calories |
|---|---|---|---|
| Protein | 1.0 g/lb | 170 g | 680 |
| Fat | 0.35 g/lb (floor) | 60 g | 540 |
| Carbs | remainder | 205 g | 820 |
| Total | ~2,040 |
Math: 2,040 - 680 (protein) - 540 (fat) = 820 cal for carbs / 4 = 205 g carbs.
Notice carbs drop but don't disappear. Keep enough to fuel training — that's what preserves muscle and strength.
How fast should the scale move?
Target: 0.5–1% of bodyweight per week.
A 170 lb guy -> about 0.85-1.7 lb/week. Faster than that and you're risking muscle and a miserable experience. Slower and you might tweak the deficit.
The adjustment protocol (this is the whole game)
You set the number once. Then you let the scale tell you when to change it. Every week:
- Take your weekly average morning weight.
- Compare to last week's average.
- Decide:
| If your weekly average... | Then... |
|---|---|
| Dropped 0.5–1% | Perfect. Change nothing. |
| Didn't move for 2 weeks | Drop calories ~150 (cut carbs) or add 1,500 daily steps |
| Dropped too fast (>1.5%) + strength tanking | Add ~150 calories — you're cutting too hard |
Don't chase the scale daily. Adjust every 1–2 weeks off the average. Patience here is literally the skill.
Cardio: a tool, not the engine
Diet creates the deficit. Cardio is a small accelerant:
- Steps first — they're sustainable and don't spike hunger. Hit your step floor before adding gym cardio.
- Then low-intensity cardio (incline walk, easy bike) 2–3x/week if needed.
- Keep some intensity (a little HIIT) only if you enjoy it — it's not required.
Avoid the trap of slashing calories AND doing hours of cardio. You'll crash. Move the smaller lever (a little cardio or steps) before you gut your food further.