Most adults need at least 0.8 grams of protein per kilogram of body weight per day, which works out to about 0.36 grams per pound. For a 150-pound person, that’s roughly 54 grams. But that number is a baseline to prevent deficiency, not necessarily the amount that’s optimal for your goals, age, or activity level. Depending on your situation, you may benefit from significantly more.
The Baseline for Sedentary Adults
The Recommended Dietary Allowance (RDA) of 0.8 g/kg was set to cover the needs of most healthy adults who aren’t particularly active. It prevents protein deficiency and supports basic body functions like immune health, enzyme production, and tissue repair. For many people with desk jobs and no specific fitness goals, hitting this number through a normal diet is straightforward. A chicken breast, a cup of Greek yogurt, and a serving of lentils throughout the day gets you there easily.
That said, a growing body of evidence suggests that 0.8 g/kg is a floor rather than a target. Most nutrition experts now view it as the minimum to avoid problems, not the amount that keeps you thriving long-term.
How Exercise Changes Your Needs
If you lift weights regularly or train for endurance events like running or cycling, your muscles need more raw material to recover and grow. The recommended range for active people is 1.2 to 1.7 grams per kilogram of body weight per day. For a 170-pound person, that translates to roughly 93 to 131 grams daily.
Where you land within that range depends on intensity. Someone doing moderate strength training a few times a week can aim for the lower end. If you’re training hard five or six days a week or actively trying to build muscle, the higher end makes more sense. Going above 1.7 g/kg doesn’t appear to offer additional muscle-building benefits for most people.
Why Protein Matters More as You Age
Adults over 65 face a challenge younger people don’t: the body becomes less efficient at using protein to maintain muscle. This gradual loss of muscle mass and strength, called sarcopenia, accelerates with each decade and raises the risk of falls, fractures, and loss of independence. The RDA doesn’t change with age, but researchers who study aging now recommend older adults consume 1.0 to 1.2 grams per kilogram per day to slow muscle loss and preserve function.
That’s a meaningful jump from the standard 0.8 g/kg. For a 160-pound older adult, it means aiming for 73 to 87 grams per day instead of 58. Spreading protein across meals (rather than loading it all into dinner) becomes especially important with age, because the body’s ability to build muscle from a single meal appears to diminish over time.
Protein for Weight Loss
Protein does two things that matter when you’re trying to lose weight. First, it’s more satiating than carbohydrates or fat, so higher-protein meals help you feel full longer and eat less overall. Second, it helps preserve lean muscle mass during a calorie deficit, which is critical because losing muscle slows your metabolism and makes regaining weight more likely.
Research on adults with overweight and obesity found that eating above 1.3 g/kg per day was associated with gaining or maintaining muscle mass, while dropping below 1.0 g/kg per day raised the risk of muscle loss. Protein also generates a higher thermic effect than other nutrients, meaning your body burns more calories digesting it. For someone actively dieting, aiming for at least 1.2 to 1.5 g/kg per day is a practical target that balances satiety, muscle preservation, and realistic meal planning.
How Much Protein Per Meal
Your body can only use so much protein at once for muscle repair. Research consistently shows that muscle-building peaks at around 30 grams of protein in a single meal. One study found that a serving of beef providing 30 grams stimulated muscle protein synthesis just as effectively as a larger portion. Eating 60 grams in one sitting doesn’t double the benefit.
That said, for people eating two or more high-protein meals per day, the effective ceiling per meal may be closer to 45 grams. The key takeaway is distribution: three or four meals each containing 30 to 45 grams of protein produces a stronger association with lean mass and muscle strength than eating most of your protein at dinner, which is the pattern many people default to. If your daily target is 100 grams, splitting that across three meals and a snack is more effective than eating 15 grams at breakfast and 70 at dinner.
Protein During Pregnancy and Breastfeeding
Protein needs increase during pregnancy, but the increase is modest in the first trimester (only about 1 extra gram per day) and ramps up significantly in the third trimester, when the baby is growing fastest. By late pregnancy, you need roughly 25 to 31 additional grams per day on top of your normal intake. For most women, that means a total daily intake in the range of 75 to 100 grams.
During breastfeeding, the additional requirement is about 19 grams per day in the first six months and drops to around 13 grams after that. Multiple international guidelines note that most pregnant and breastfeeding women can meet these requirements through a regular diet without supplements, as long as total calorie intake is adequate.
Adjusting for Body Composition
Standard protein calculations use total body weight, which works well for people at a healthy weight. But if you carry a significant amount of extra body fat, using total weight can overestimate your protein needs. Fat tissue doesn’t require protein the way muscle does. A 280-pound person with 40% body fat doesn’t need twice the protein of a 140-pound lean person.
Research comparing protein calculations based on total body weight versus fat-free mass found clinically meaningful differences in most participants with obesity. If you’re significantly overweight, calculating protein based on your goal weight or lean body mass gives a more accurate target. A simpler approach: use 1 gram per pound of your goal body weight as a rough guideline that accounts for both your current size and where you’re headed.
Is Too Much Protein Harmful?
For healthy people, high-protein diets are not known to cause medical problems. The long-standing concern about protein damaging kidneys comes from studies on people who already had kidney disease, where the kidneys struggle to clear protein’s waste products. In people with normal kidney function, there’s no strong evidence that eating 1.5 or even 2 g/kg per day causes harm.
The real risk of very high protein intake is less dramatic: it can crowd out other important nutrients. If you’re eating 200 grams of protein a day, you may be skimping on fiber, healthy fats, or the variety of micronutrients that come from fruits, vegetables, and whole grains. For people with existing kidney disease or diabetes, higher protein intake does warrant more caution and medical guidance. But for the average healthy adult wondering if their protein shake habit is dangerous, the answer is almost certainly no.
Quick Reference by Goal
- General health (sedentary): 0.8 g/kg body weight (about 0.36 g/lb)
- Active adults and regular exercisers: 1.2 to 1.7 g/kg
- Weight loss while preserving muscle: 1.2 to 1.5 g/kg
- Adults over 65: 1.0 to 1.2 g/kg
- Pregnancy (third trimester): normal intake plus 25 to 31 g/day
- Breastfeeding: normal intake plus 13 to 19 g/day
To convert your weight: divide your weight in pounds by 2.2 to get kilograms, then multiply by the g/kg target that fits your situation. A 180-pound active adult aiming for 1.5 g/kg would calculate 180 ÷ 2.2 = 82 kg, then 82 × 1.5 = 123 grams of protein per day.