How Much Protein Per Day Needs By Age And Activity?

Protein needs change across your lifetime, and the amount that supports a sedentary office worker is not the same amount that supports a competitive athlete or a 75-year-old trying to preserve muscle. For most healthy adults, the Recommended Dietary Allowance is 0.8 grams of protein per kilogram of body weight per day. That works out to roughly 56 grams daily for a 70 kg (154 lb) man and about 46 grams for a 57 kg (125 lb) woman. But that number is a minimum to prevent deficiency, not a target for optimal health at every age and activity level.

What Is the Standard Protein Recommendation for Adults?

The 0.8 g/kg/day figure comes from the Institute of Medicine (now the National Academy of Medicine) and represents the amount needed to meet the basic nutritional requirements of nearly all healthy, sedentary adults. It is calculated from nitrogen balance studies, which measure how much protein the body retains versus how much it loses.

That number was designed to prevent deficiency, not to optimize muscle mass, bone health, or healthy aging. This is where most confusion starts. People hear “0.8 g/kg” and assume it is the ideal target for everyone. It is not. It is the floor.

To put it in practical terms, here is what 0.8 g/kg/day looks like across a range of body weights:

For a sense of scale, a large egg contains about 6 grams of protein. A 3-ounce chicken breast has roughly 26 grams. A cup of cooked lentils provides about 18 grams. Hitting 56 grams in a day is not difficult for most people eating a mixed diet, but it does require some attention for those who skip meals or eat mostly processed foods.

How Much Protein Do You Need If You Exercise?

Physical activity increases protein requirements. Exercise causes microscopic damage to muscle fibers, and the body uses amino acids from dietary protein to repair and rebuild that tissue. The more you train, the more protein your body needs to recover.

For recreational exercisers who work out a few times a week, research suggests roughly 1.1 to 1.4 grams per kilogram of body weight per day. For people doing regular resistance training or endurance training at a moderate to high volume, the range shifts higher, to about 1.4 to 1.7 g/kg/day.

Competitive athletes and those in heavy training blocks may need up to 2.0 g/kg/day. Some research indicates that very high-volume strength athletes can benefit from intake at the upper end of that range, though there is a point of diminishing returns. The body can only use so much protein for muscle repair in a given period.

It is worth noting that these higher intakes are not just about muscle. Endurance athletes also break down protein during long training sessions, and adequate intake helps preserve lean mass during periods of heavy calorie expenditure.

Here is what those ranges look like for a 70 kg (154 lb) person:

• Sedentary: about 56 g/day
• Recreational exerciser: about 77–98 g/day
• Regular resistance trainer: about 98–119 g/day
• Competitive athlete: up to about 140 g/day

These are general ranges from sports nutrition research. Individual needs vary based on training intensity, total calorie intake, age, and whether the person is trying to build muscle or maintain it.

Do Protein Needs Change With Age?

Yes, and this is one of the most important shifts in protein research over the past two decades. Adults over 65 need more protein than younger adults to maintain muscle mass, even if they are not exercising.

The reason is a condition called anabolic resistance. As people age, their muscles become less responsive to the anabolic (muscle-building) signal from dietary protein. A younger adult might build muscle efficiently after eating 20 grams of protein in a meal. An older adult may need 30 to 40 grams in that same meal to get a similar response.

Research in this area suggests that healthy older adults should aim for roughly 1.0 to 1.2 grams of protein per kilogram of body weight per day, with some researchers recommending 1.2 to 1.5 g/kg/day for those who are frail, recovering from illness, or at risk of sarcopenia (age-related muscle loss).

For a 70 kg (154 lb) older adult, that means about 70 to 105 grams per day, depending on health status. This is meaningfully higher than the standard 0.8 g/kg recommendation.

Sarcopenia affects roughly 5–13% of adults aged 60–70 and up to 50% of those over 80, according to some estimates. Adequate protein intake, combined with resistance exercise, is one of the few interventions shown to slow its progression.

How Much Protein Do Children and Teenagers Need?

Children and adolescents need protein for growth, not just maintenance. Their requirements are higher per kilogram of body weight than adults because they are actively building new tissue.

According to the Institute of Medicine’s Dietary Reference Intakes, the RDA for protein by age group is:

For a 10-year-old weighing 32 kg (about 70 lb), that is roughly 30 grams per day. For a 15-year-old boy weighing 60 kg (132 lb), it is about 51 grams per day.

Teenage athletes may need more, but there is less research on protein requirements in adolescent athletes than in adults. Some sports nutrition guidelines suggest 1.2 to 1.6 g/kg/day for active teenagers, but the evidence base is thinner. No clinical guidelines currently exist for protein supplementation in children and adolescents outside of medical supervision.

Does Protein Need Change During Pregnancy and Breastfeeding?

Yes. Pregnancy and breastfeeding increase protein needs because the body is building fetal tissue, the placenta, and producing milk.

The RDA for pregnant women is 1.1 grams per kilogram of body weight per day. For breastfeeding women, it is 1.3 g/kg/day. These are established recommendations from the Institute of Medicine.

For a 65 kg (143 lb) pregnant woman, that is about 71 grams per day. While breastfeeding, it rises to about 84 grams per day.

These are minimums to support healthy fetal development and milk production. Some research suggests that higher intakes may be beneficial in certain cases, but the evidence is not strong enough to recommend a specific higher target for all pregnant or breastfeeding women.

Protein needs during pregnancy and breastfeeding should be discussed with a healthcare provider, especially for women with kidney conditions, preeclampsia, or other complications.

Can You Eat Too Much Protein?

For most healthy adults, protein intakes up to 2.0 g/kg/day are considered safe and do not harm kidney function. This is supported by multiple studies in healthy populations.

The concern about kidney damage from high protein intake comes from research in people who already have kidney disease. In those individuals, reducing protein intake can slow disease progression. But in people with healthy kidneys, higher protein intakes have not been shown to cause harm in controlled studies.

That said, very high intakes (above 2.0 g/kg/day) offer no additional benefit for most people and may displace other important nutrients from the diet. Protein-rich foods can also be high in saturated fat if they come from certain animal sources, which matters for heart health.

People with chronic kidney disease, liver disease, or certain metabolic disorders should follow protein recommendations from their healthcare provider, not general guidelines.

Another point often missed: protein quality matters. Animal proteins and soy are complete proteins, meaning they contain all nine essential amino acids. Most plant proteins are incomplete on their own, but eating a variety of plant foods throughout the day can provide all essential amino acids.

How Do You Calculate Your Own Protein Target?

Start with your body weight in kilograms. If you know your weight in pounds, divide by 2.2 to get kilograms. Then multiply by the grams-per-kilogram figure that matches your age and activity level.

For example, a 40-year-old recreational runner weighing 68 kg (150 lb) would fall into the 1.1–1.4 g/kg range. That is about 75–95 grams per day. A 70-year-old sedentary adult weighing 80 kg (176 lb) would aim for 1.0–1.2 g/kg, or about 80–96 grams per day.

These are estimates. Individual needs vary. If you are unsure, a registered dietitian can help you set a target based on your health history, medications, and goals.