Muscle gain: build, don't balloon.

A dirty bulk — eating in a massive surplus without watching what's on the plate — works on paper. You put on size, sure, but a big chunk of it is fat. Six months later, you're left with a few pounds of real muscle, a lot of fat to drop, and a chipped motivation.

A lean bulk works on a different idea: a modest surplus (5 to 15% above maintenance), steady macros, measured progress. You gain slower, but what you gain is more usable. The cut that follows is shorter, less painful, and your energy stays steady the whole way through.

There's no perfect surplus number. What exists are reasonable ranges and the discipline to adjust. That's exactly what we're about to walk through.

Protein: 0.7 to 1.0 g per pound

That's the research-backed range for hypertrophy (roughly 1.6 to 2.2 g per kilo). Below it, you cap your muscle protein synthesis. Above it, there's no extra benefit — just more nitrogen to flush. For a 165 lb lifter, that's 120 to 165 g of protein per day, spread across 3 to 5 meals.

Fat: 0.35 to 0.5 g per pound

Fat keeps your hormones running, testosterone included. Drop below that range for too long and you risk tanking your hormonal output and recovery. Stick to the good sources: olive oil, avocado, nuts, fatty fish, egg yolks.

Carbs: the fuel that fills the rest

Once protein and fat are locked in, carbs take whatever calories are left. They're the main fuel for your training. On a heavy training day, you can easily land at 2 to 3 g per pound. Best sources around workouts: rice, sweet potato, oats, whole-grain bread, fruit.

Crunch the numbers once, track them daily

You can do the math by hand, or let ZymFit pull it straight from your profile. From there, the app gives you three ways to log meals: AI photo scan, barcode scan, and manual search. New to macros? We wrote a dedicated guide on calculating your surplus and macros for muscle gain.

The 7-day moving average

Weigh in every morning, fasted, after the bathroom, before drinking. Across 7 consecutive days, calculate the average. Compare that average to last week's. That difference — not today's raw number — is what tells you where you're heading.

The right rate of gain

For a beginner, aiming for 0.3 to 0.5% of body weight per week is reasonable. For an intermediate, 0.2 to 0.3%. For an advanced lifter, 0.1 to 0.2%. For a 165 lb intermediate, that's about 0.3 to 0.5 lb per week. Faster than that, and the extra gain is almost certainly fat.

Reading the smoothed line

ZymFit shows your trend as a 7-day moving average specifically to filter out the daily zigzag. You see the real slope, not the noise. Want to dig into how it works? We wrote a piece on reading the true weight trend.

Watch before you touch

Give yourself 2 to 3 weeks of data before changing anything. One week of flat progress is noise. Three weeks of flat progress at steady macros is a real signal.

Three scenarios, three adjustments

If you're gaining faster than the target range (say +1.3 lb/week instead of 0.5), drop 150 to 200 kcal/day, mostly off non-training-day carbs. If you stall for 3 weeks, add 100 to 200 kcal/day. If you're gaining at the right rate but your waist is growing faster than your arms, cut 100 kcal and check your training volume.

Change one variable at a time

If you tweak your calories, your program, and your sleep all at once, you'll never know what worked. One variable, two weeks of watching, then the next. It's slow, it's boring, it's what works.