The number, up front

For a healthy adult who is training with the intent to build or preserve muscle, the actual research consensus lands in this range:

  • Maintenance or surplus (bulking): 0.7 to 1.0 grams of protein per pound of bodyweight per day.
  • Calorie deficit (cutting): 0.9 to 1.1 grams per pound. Higher protein protects muscle when calories are low.
  • Older adults (50+): 1.0 to 1.2 grams per pound. Older muscle is more resistant to protein synthesis signals, so you need a bit more to get the same effect.

For a 180-pound person, that's between 130 and 200 grams of protein per day depending on goal and age. Not 350. Not 270. 130 to 200.

This is what the meta-analyses have been saying for over a decade. The 1.5-2 grams per pound number you've heard at the gym predates most of that research and was largely propagated by supplement company marketing in an era where higher-protein meant selling more whey.

Where the number came from

The most cited synthesis paper on this is the 2018 meta-analysis from Morton, Murphy, McKellar, et al. in the British Journal of Sports Medicine. They pooled 49 studies of resistance-trained adults and found:

  • Protein intake increases muscle gain up to roughly 1.6 grams per kilogram of bodyweight per day — that's about 0.73 grams per pound.
  • Above that threshold, additional protein intake produced no additional muscle gain in the studies they examined.
  • The 95% confidence interval upper bound was about 2.2 g/kg (1.0 g/lb), which is why most evidence-based coaches recommend the 0.7 to 1.0 range.

This is a well-replicated finding. Phillips, Helms, Aragon, and others have all converged on similar numbers. There is no current evidence that pushing protein much above 1.0 g/lb does anything for muscle gain in a non-clinical population.

Why the gym number is so much higher

Three reasons the broscience number runs 50-100% above the actual research:

  1. Bodybuilders historically over-shot to be safe. When you don't know the threshold, eating extra protein is the conservative play. Once a generation of bodybuilders normalized 1.5-2 g/lb, the next generation inherited it as gospel.
  2. Protein supplement marketing. Selling whey protein at scale required convincing people they needed enormous amounts of it. That message saturated fitness media for two decades.
  3. Real exceptions exist. Elite bodybuilders in heavy contest prep on prescription anabolics may genuinely benefit from higher protein intake. That edge case got generalized to everyone in the gym.

What about distribution across the day?

The research on protein distribution is messier than the research on total daily intake. The general findings:

  • Spreading protein across 3-5 meals seems to slightly outperform getting it all in 1-2 meals, especially for older adults.
  • Per-meal threshold for maximum muscle protein synthesis is around 0.4 grams per kilogram per meal — about 30-40 grams of high-quality protein for most adults.
  • Pre-bed protein has a small effect in some studies, especially with slow-digesting protein (casein, cottage cheese). Worth doing if it fits your eating pattern, not worth forcing.
  • Protein timing around training (the "anabolic window") barely matters. As long as your daily total is right and you eat protein within a few hours of training, the timing details fall in the noise.

The practical upshot: hit your daily total, spread it across 3-5 meals if convenient, don't stress about the rest.

Endurance athletes and hybrid trainers

If you're primarily an endurance athlete (distance running, cycling, triathlon) you can usually get away with the lower end of the range — 0.7-0.8 g/lb is plenty. Your training stimulus is different and the protein needs scale less aggressively with volume.

Hybrid athletes (CrossFit-style, the kind of person who lifts heavy and runs hard) should aim for the middle of the range — 0.8-0.9 g/lb. The strength stimulus warrants more protein than pure endurance work, but the volume of training can crowd out appetite, so 1.0+ g/lb is hard to actually eat.

This is part of why TrakMac's protein target adjusts based on the fitness assessment. Your training profile changes the recommended intake within this evidence-based range.

Plant-based protein

A practical adjustment: if your protein is mostly from plant sources (legumes, grains, tofu, seitan), bump your target by 10-15%. Plant proteins have less complete amino acid profiles and slightly lower digestibility scores than animal proteins. The fix is volume — eating a bit more, especially of the higher-quality plant sources (soy, peas, hemp). For someone targeting 150g animal-based, the plant-based equivalent is closer to 170g.

This is not a moral argument about diet. It's a math argument about amino acid availability.

How to actually hit the number

Protein intake is the single most under-hit macro for people who track. Almost everyone undershoots until they actively focus on it. Some practical adjustments that move the number reliably:

  • Front-load protein at breakfast. Two eggs and toast is 14g of protein. Two eggs and toast plus a Greek yogurt or a scoop of cottage cheese gets you to 35g. Same calories range, double the protein. Most undershooters are losing the day at breakfast.
  • Default to higher-protein options. Chicken breast over thigh, Greek yogurt over regular, cottage cheese over cheese, lean ground beef over fattier blends. None of these are huge per-meal differences. Stacked across the day they're 50+ grams.
  • A protein shake closes any gap. One scoop of whey isolate is 25g of protein for 110 calories. For people who consistently hit 130g but want to be at 160g, this is the laziest fix.

If you're using TrakMac, the daily protein number on your dashboard is the one to focus on. Carbs and fat can flex around your eating preferences. Protein is the one to actually hit.

When the higher numbers do make sense

For full transparency: a few populations should target the high end of the range or slightly above it.

  • People in aggressive calorie deficits (more than 25% below maintenance) — protein protects muscle when calories are low.
  • People over 65 — sarcopenia (age-related muscle loss) is partially offset by higher protein intake.
  • People recovering from injury or surgery, where tissue repair demands are elevated.
  • People on GLP-1 medications, where appetite suppression makes hitting protein especially hard. The compensation is to make every meal protein-dense.

For everyone else: 0.7-1.0 g/lb is the answer, and the difference between 0.7 and 1.0 matters less than the difference between hitting your number and missing it by 30%.