1.6 – 1.8 g / kg
In a calorie surplus, the extra energy already protects your muscle. No need to chase the top of the range: 1.6 to 1.8 g/kg is enough to support growth.
Blog · Nutrition
How much protein per day for strength training?
May 24, 20269 min readBy ZymFit
Short answer: to build muscle, aim for 1.6 to 2.2 g of protein per kilogram of body weight per day. That's the range backed by recent meta-analyses for anyone training seriously in the gym. There's no need to push much higher — beyond that, the marginal gains become negligible.
The real questions are how to adjust that number to your goal, how to spread it across the day, and where to actually source your protein. That's what we unpack here, without folklore and without pushing any brand.
01 / The range
The 1.6 to 2.2 g per kilogram rule
Three references form the consensus in the literature. The review by Helms et al. (2014) suggests 2.3 to 3.1 g of protein per kilogram of lean body mass for athletes in a deficit, which lands most lifters around 1.8 to 2.2 g/kg of total body weight.
The meta-analysis by Morton, Murphy, McKellar et al. (2018) places the useful ceiling at roughly 1.6 g/kg/day, beyond which additional gains in lean mass become negligible. The ISSN position stand (Jäger et al., 2017) recommends 1.4 to 2.0 g/kg/day as the working range for strength and hypertrophy athletes.
In practice, only one thing to remember: 1.6 to 2.2 g/kg/day covers almost every situation. Lower than that, you blunt muscle protein synthesis. Higher, you're just filling your plate without any measurable benefit.
02 / Goal
Dial it in to your goal
Where you sit inside the range shifts depending on whether you're eating in a surplus, at maintenance, or in a deficit. Here's the simple grid to keep in mind.
1.6 – 2.0 g / kg
The standard for lifters looking to stabilize or recomp. 1.8 g/kg is a solid anchor point for the vast majority of cases.
2.0 – 2.5 g / kg
In a deficit, muscle is more exposed. Pushing to 2.2 or even 2.5 g/kg helps preserve lean mass and satiety as calories drop.
For cutting specifically, the Helms meta-analysis is clear: the more aggressive the deficit and the leaner the athlete, the more protein needs to climb. We dig into the mechanics in our full cutting protocol guide.
Important note: if you're significantly overweight, calculate your protein from your target weight or your estimated lean body mass, not your current scale weight. Otherwise, 2 g/kg on a 243 lb (110 kg) frame works out to 220 g of protein per day — far more than necessary.
03Distribution
How much per meal (and why)
Daily total matters most. Distribution matters too, but less than people claim. The useful principle: to fully trigger muscle protein synthesis, a meal needs enough leucine. The threshold sits around 2.5 to 3 g of leucine, which in practice translates to 30 to 40 g of protein per sitting for an adult.
The simple rule: 4 to 5 servings of 30 to 40 g spread across the day. Three solid meals plus one or two protein snacks — that's exactly what you need. You don't have to force-feed yourself every 3 hours on the dot: order of magnitude is what matters, not the clock.
For older lifters or those on a plant-based diet, aiming toward the higher end (35 to 40 g per meal) compensates for a slightly weaker anabolic response per gram of protein.
Pocket rule
4 to 5 × (30 to 40 g) = daily target
For a 150 g total, that's 4 meals of ~38 g. For 180 g, 5 servings of ~36 g.
04 / Sources
Where to source your protein
A good protein source ticks three boxes: a complete essential amino acid profile, high protein density, and solid digestibility. Here are the staples worth knowing, both animal and plant-based.
Animal
Complete profile, high density
- Chicken breast — 31 g / 100 g
- Whole eggs — 13 g / 100 g (≈ 6 g per egg)
- Whey or casein — 22 to 25 g per scoop
- Skyr or Greek yogurt — 10 to 11 g / 100 g
- Tuna, cod, salmon — 20 to 25 g / 100 g
- Lean beef 5% — 26 g / 100 g cooked
Plant-based
Vary sources to cover amino acids
- Firm tofu — 14 to 17 g / 100 g
- Tempeh — 19 g / 100 g
- Seitan — 20 to 25 g / 100 g
- Cooked lentils — 9 g / 100 g
- Cooked chickpeas — 8 g / 100 g
- Rice + pea protein blend — complete profile
On the plant side, the point to watch is complementarity. Grains are low in lysine, legumes are low in methionine. Combining the two across the day (and ideally within the same meal) is enough to get a complete profile, no fancy math required.
A simple trick to log these servings without manual entry: you can scan your plate with a photo and let ZymFit estimate the grams of protein on it.
05Timing
The anabolic window myth
For years, we were told that 30 g of whey absolutely had to hit your bloodstream within 30 minutes of your last set or you'd lose your gains. The Schoenfeld and Aragon (2018) meta-analysis dismantled that dogma: the famous anabolic window doesn't last 30 minutes, it spans several hours both before and after the session.
The right mental model: your useful window is the whole day. As long as you're eating protein every 3 to 5 hours, with one serving in the 2 to 3 hours after training, you'll tick every box.
Edge case: if you train fasted in the morning, far from your last meal, then yes — a fast-acting protein source right after the session makes sense. Otherwise, don't burn energy optimizing a detail that barely moves the needle.
06 / Real world
Three real-world cases to anchor the numbers
Numbers click better once they're attached to real profiles. Here are three examples that cover the most common situations.
Male · Cutting
165 lb (75 kg) · 4 sessions / wk
≈ 165 g / day
2.2 g/kg, split into 4 meals of 40 g + 1 skyr snack
In a 400 kcal deficit, protein stays high to preserve strength and lean mass despite the cut.
Female · Recomp
132 lb (60 kg) · 3 sessions / wk
≈ 110 g / day
1.8 g/kg, split into 4 servings of 25 to 35 g
Calories around TDEE. The goal is slow muscle gain and fat loss in parallel: protein does most of the heavy lifting.
Male · Muscle gain
187 lb (85 kg) · 5 sessions / wk
≈ 150 g / day
1.75 g/kg, split into 5 meals of 30 g
In a +300 kcal surplus, no need to push to 2 g/kg: the extra calories already spare muscle protein.
One thing to notice: none of these cases tops 2.5 g/kg. That's deliberate. Beyond that point, you add digestive workload without any further gain on lean mass — better to leave room for carbs to fuel your sessions. If you're just getting started in the gym, take a look at our beginner strength training program first: without proper stimulus, eating more protein won't do much for you.
FAQ
The questions we get asked most
Does too much protein damage your kidneys?
In healthy individuals, no study has shown that a high protein intake (up to 2.5 or even 3 g/kg) causes kidney damage. The review by Devries et al. (2018) found no negative effect on kidney function. If you have a pre-existing kidney condition, talk to your doctor before raising your intake.
Is whey protein essential?
No. Whey is convenient, affordable and easy to digest, but it's just one protein source among many. If you hit your 1.6 to 2.2 g/kg from chicken, eggs, yogurt, tofu or legumes, you have no need for it. Powder mainly fills the gap on busy days when whole-food sources are hard to fit in.
How much protein for a woman doing strength training?
Protein needs scale with body weight, not sex. A 132 lb (60 kg) woman aiming to build muscle should target 1.6 to 2.0 g/kg, which works out to about 96 to 120 g of protein per day. During a cut, she can push up to 2.2 g/kg to better preserve lean mass.
Does protein powder make you fat?
Protein doesn't make you gain weight — calories do. One scoop of whey is roughly 120 kcal. If it fits inside your calorie target, it won't add body fat. The problem only shows up when it's added on top of a diet that's already dialed in.
Should you take protein before or after your workout?
It doesn't matter precisely, as long as you eat a protein source within the 3 to 4 hours around your session. The Schoenfeld and Aragon (2018) meta-analysis showed that the famous 30-minute anabolic window is widely overstated. Your daily total spread across 4 to 5 meals matters far more.
Can you build muscle on plant proteins only?
Yes, as long as you vary your sources to cover all the essential amino acids and push your daily total slightly higher (around 1.8 to 2.2 g/kg). Combining rice + legumes, tofu, tempeh, seitan and a pea or soy isolate gets the job done.
Ready to try it
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