How Much Protein Do I Need Per Day?
The Short Answer
Most adults do well on 1.2 to 1.6 grams of protein per kilogram of body weight per day, above the 0.8 g/kg RDA that only prevents deficiency. If you lift weights, added protein stops improving muscle gain at about 1.6 g/kg. During a calorie deficit, go higher. For a 70 kg adult that is roughly 84 to 112 grams.
Why Doesn't One Protein Number Work for Everyone?
Ask five sources how much protein you need and you will get five answers, ranging from 50 grams to 200. They are not contradicting each other so much as answering different questions. One number prevents deficiency. Another maximises muscle growth. A third protects lean mass while you are eating less than you burn.
Protein needs also scale with body size, which is why any answer given in flat grams per day is only right for the person it was calculated for. The research reports targets in grams per kilogram of body weight, and that is how this guide works too.
What Is the Minimum Protein I Need Per Day?
The Recommended Dietary Allowance for protein is 0.8 grams per kilogram of body weight per day, set by the Institute of Medicine in 2005. For a 70 kg adult that comes to 56 grams.
Read how the RDA is defined and the number stops looking like a goal. It is the intake that meets the requirements of 97 to 98 percent of healthy people, meaning it is the level at which almost nobody develops a deficiency. Nothing in that definition promises optimal muscle retention, bone health, or appetite control. It is a floor.
Almost every population studied since has done better on more.
| Body weight | 0.8 g/kg (RDA) | 1.2 g/kg | 1.6 g/kg | 2.0 g/kg |
|---|---|---|---|---|
| 55 kg (121 lb) | 44 g | 66 g | 88 g | 110 g |
| 70 kg (154 lb) | 56 g | 84 g | 112 g | 140 g |
| 85 kg (187 lb) | 68 g | 102 g | 136 g | 170 g |
| 100 kg (220 lb) | 80 g | 120 g | 160 g | 200 g |
How Much Protein Do I Need to Build Muscle?
Morton and colleagues pooled 49 studies covering 1,863 participants for a 2018 meta-analysis in the British Journal of Sports Medicine. Extra protein reliably improved strength and fat-free mass gains during resistance training, with one important qualification: the benefit flattened at a total intake of 1.62 g/kg per day. Beyond that point, more protein produced no further measurable gain in fat-free mass.
That figure is the most useful single number in the protein literature. It gives you a target that is high enough to matter and a ceiling that saves you money.
The International Society of Sports Nutrition's 2017 position stand lands in the same territory, recommending 1.4 to 2.0 g/kg per day for building and maintaining muscle in exercising individuals. The upper half of that range makes sense if you are training hard or eating in a deficit; the lower half is fine for general training.
For an 85 kg lifter, 1.6 g/kg is 136 grams a day. Four meals of roughly 30 to 35 grams gets you there, which lines up with what we cover in how much protein you need per meal.
How Much Protein Should I Eat While Losing Weight?
Protein needs go up when calories go down, for two reasons that reinforce each other.
The first is muscle preservation. Longland and colleagues (2016, American Journal of Clinical Nutrition) put young men in a 40 percent energy deficit for four weeks with hard training. The group eating 2.4 g/kg gained 1.2 kg of lean mass and lost 4.8 kg of fat. The group eating 1.2 g/kg held their lean mass steady and lost 3.5 kg of fat. Same deficit, better body composition on the higher intake.
Helms and colleagues (2014) reviewed the evidence for lean, resistance-trained athletes cutting weight and recommended 2.3 to 3.1 g/kg of fat-free mass, scaled up as the deficit deepens and the athlete gets leaner. Those are the highest numbers in the mainstream literature, and they apply to a specific population: already lean people in an aggressive cut.
The second reason is appetite. Protein is the most satiating macronutrient per calorie, so a high-protein deficit is simply easier to stick to than a low-protein one. If you are working out how many calories to eat to lose weight, setting protein first and letting carbs and fat fill the remainder is the practical way to build the plan.
For most people losing weight without competition-level leanness, 1.6 to 2.2 g/kg of body weight covers it.
Do Protein Needs Change After 50?
They rise. Ageing muscle shows what researchers call anabolic resistance: the same dose of protein triggers a smaller muscle-building response than it did at 25.
The PROT-AGE study group (Bauer et al., 2013) recommended 1.0 to 1.2 g/kg per day for healthy older adults, and 1.2 to 1.5 g/kg for those with acute or chronic illness. Older adults with severe illness or injury may need more still.
The irony is that appetite tends to fall with age at exactly the point where the requirement climbs. Anyone over 65 tracking intake for the first time is often surprised at how far under they are.
What Do These Targets Look Like in Real Food?
Targets in g/kg are abstract until you see the portions. Every figure below comes from USDA FoodData Central.
| Food | Portion | Protein |
|---|---|---|
| Chicken breast, roasted | 3 oz (85 g) | 26 g |
| Sirloin steak, broiled | 3 oz (85 g) | 25 g |
| Canned light tuna in water, drained | 1 can (165 g) | 42 g |
| Salmon, cooked | 3 oz (85 g) | 19 g |
| Tempeh, cooked | 100 g | 20 g |
| Greek yogurt, plain nonfat | 170 g cup | 18 g |
| Lentils, boiled | 1 cup (198 g) | 18 g |
| Black beans, boiled | 1 cup (172 g) | 15 g |
| Tofu, firm | 1/2 cup (126 g) | 11 g |
| Cottage cheese, 2% | 100 g | 11 g |
| Egg, hard-boiled | 1 large (50 g) | 6 g |
Two things usually stand out. Eggs are a weaker protein source than their reputation suggests, at roughly 6 grams each, so a three-egg breakfast is a 19-gram meal before you add anything. And a cup of beans or lentils holds real protein, but you need volume to compete with meat.
You can check any individual food against USDA figures on our protein content pages, including salmon, steak, and black beans.
How Do You Hit a Protein Target Without Weighing Every Meal?
Most people miss their protein target for a boring reason: they never find out what they are actually eating. Estimating protein by eye is unreliable, and the error runs in one direction, because the foods people forget to count are rarely the chicken breast.
A week of honest logging fixes the estimate problem faster than any rule of thumb. Forkd logs meals from a photo, a voice note, or a line of text, then shows protein against your daily target as a running total, so you know at 3pm whether dinner needs to carry 20 grams or 45. Search the App Store for "AI Calorie Tracker: Forkd" to try it.
After two or three weeks the tracking becomes mostly redundant, because you have learned what 30 grams looks like on a plate. That is the actual goal.
Frequently Asked Questions
Is 100 grams of protein a day enough?
It depends on your body weight and goals. For a 62 kg adult, 100 grams is 1.6 g/kg, which is enough to support muscle growth alongside resistance training. For a 100 kg adult, it is exactly the 1.0 g/kg mark: above the RDA but below the range associated with better lean mass retention. Convert to g/kg before judging any flat number.
Can you eat too much protein?
Healthy adults tolerate high protein intakes well. Studies running up to 3.3 g/kg per day in resistance-trained people found no harm to kidney or liver function. The practical limits are cost, appetite, and displacement: protein calories eaten past the point of benefit crowd out carbohydrate that would have fuelled training. People with existing kidney disease are the exception and should follow the intake their doctor sets.
Does protein from plants count the same as protein from meat?
For daily totals, yes, with one adjustment. Most plant proteins are lower in one or more essential amino acids, particularly leucine, so the muscle-building response per gram is smaller. Eating a varied mix of legumes, grains, soy, nuts, and seeds across the day resolves the amino acid gaps. Soy foods such as tofu and tempeh come closest to animal protein on their own. Adding roughly 10 to 20 percent to your target is a reasonable hedge on an entirely plant-based diet.
Should I count protein per kilogram of body weight or lean mass?
Body weight works for most people. Lean mass (fat-free mass) is the more precise basis at higher body fat percentages, since fat tissue has little protein requirement, so a 120 kg person at 40 percent body fat would overshoot badly using total weight. If you know your body fat percentage, use fat-free mass with the Helms range. Otherwise use body weight with the 1.2 to 1.6 g/kg range.
Do I need protein immediately after training?
The 30-minute anabolic window turned out to be much wider than early research suggested. Total daily protein matters far more than timing. Muscle stays sensitised to protein for at least 24 hours after resistance training, so a normal meal within a few hours is fine. Spreading intake across three or four meals still beats stacking it all into one.
Key Takeaways
- The 0.8 g/kg RDA prevents deficiency; it is not a performance or body composition target.
- Added protein stops improving muscle gains at about 1.62 g/kg per day (Morton et al., 2018).
- In a calorie deficit, higher intakes protect lean mass. Lean trained athletes may need 2.3 to 3.1 g/kg of fat-free mass.
- Adults over 65 should aim for 1.0 to 1.2 g/kg minimum because ageing muscle responds less to each dose.
- Convert every recommendation into grams per kilogram before acting on it, then check it against real portions.
References
- Institute of Medicine (2005). Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. National Academies Press. nap.nationalacademies.org
- Morton, R.W., et al. (2018). A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength in healthy adults. British Journal of Sports Medicine, 52(6), 376-384. pubmed.ncbi.nlm.nih.gov
- Jäger, R., et al. (2017). International Society of Sports Nutrition Position Stand: protein and exercise. Journal of the International Society of Sports Nutrition, 14, 20. ncbi.nlm.nih.gov
- Longland, T.M., et al. (2016). Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss. American Journal of Clinical Nutrition, 103(3), 738-746. ajcn.nutrition.org
- Helms, E.R., et al. (2014). A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: a case for higher intakes. International Journal of Sport Nutrition and Exercise Metabolism, 24(2), 127-138. journals.humankinetics.com
- Bauer, J., et al. (2013). Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group. Journal of the American Medical Directors Association, 14(8), 542-559. pubmed.ncbi.nlm.nih.gov
- USDA FoodData Central. Protein values for chicken breast (171477), sirloin steak (169458), tuna (171986), salmon (175168), tempeh (172467), Greek yogurt (330137), lentils (172421), black beans (173735), tofu (172448), cottage cheese (328841), and egg (173424). fdc.nal.usda.gov
Written by
Vineet Karhail builds Forkd, the AI-powered calorie and nutrition tracking app, and writes its research-backed guides on calories, macros, and micronutrients.
