The amount of protein you need depends on many factors, including activity level, age, muscle mass, and overall health.

Protein is one of three essential macronutrients, alongside carbohydrates and fats. These are nutrients that the human body needs in relatively large quantities to function properly.

Most official nutritional organizations recommend a fairly modest protein intake. However, opinions regarding how much protein you need vary.

The Food and Drug Administration suggests that most US adults require around 50 grams (g) of protein daily. However, this total depends of your age, sex, health status, and activity levels. (1)

This article examines the optimal amounts of protein and how lifestyle factors like weight loss, muscle building, and activity levels factor in.

Proteins are the main building blocks of your body. They’re used to make muscles, tendons, organs, and skin, as well as enzymes, hormones, neurotransmitters, and various molecules that serve many important functions (2).

Proteins consist of smaller molecules called amino acids, which link together like beads on a string. Your body produces some of these amino acids, but you must obtain others known as essential amino acids via your diet.

Different dietary sources of protein have different amino acid compositions. Many lean meats and dairy products contain all the ‘essential’ amino acids, while these are less abundant in a plant-based diet (3).

However, with a small amount of research and nutritional consideration, it is perfectly possible to get all the essential protein elements in good quantities on a plant-based diet. For example, complete vegan protein powders and other supplements are a helpful way to reach protein targets.

Summary

Protein is a structural molecule comprising amino acids, many of which your body can’t produce on its own. Animal foods are usually high in protein, providing all essential amino acids.

Protein is important when it comes to losing weight. As you may know, you need to consume fewer calories than you burn to lose weight.

Evidence suggests that eating protein can increase the number of calories you burn by boosting your metabolic rate (calories out) and reducing your appetite (calories in) (4).

A 2020 review and meta-analysis concluded that a long-term high protein diet could increase weight loss, reduce the risk of gaining weight back, and help prevent obesity and obesity-related diseases (5).

Summary

A protein intake at around 30% of calories seems to be optimal for weight loss. It boosts your metabolic rate and causes a spontaneous reduction in calorie intake.

As with most body tissues, muscles are dynamic and constantly being broken down and rebuilt. To gain muscle, your body must synthesize more muscle protein than it breaks down.

As such, people who want to build muscle often eat more protein, as well as exercise. A higher protein intake can help build muscle and strength (6).

For example, a 2018 meta-analysis concluded that dietary protein supplementation significantly increased muscle strength and size following a weight training program in healthy adults (7).

The authors of the above analysis found that protein intakes of 1.6 g/kg/day were adequate to support muscle building and improve performance.

Summary

It’s important to eat enough protein if you want to gain and/or maintain muscle. Most studies suggest that 0.7–1 gram per pound (1.6–2.2 grams per kg) of lean mass are sufficient.

During pregnancy, the body needs more protein for tissue development and growth. Protein benefits both the parent and the baby.

The Food and Drug Administration’s Dietary Guidelines for Americans notes that people require around 70 g of protein daily during pregnancy. This equates to 10–35% of daily calorie intake in most cases (1).

People who are chestfeeding also require higher-than-typical protein intake.

As in all situations, lean meats, fish, dairy, and legumes are good protein sources during pregnancy. However, during pregnancy and lactation, choose fish that are low in mercury and high in omega-3 fatty acids, such as salmon, sardines, and anchovies.

However, take care to avoid those that may be high in mercury, such as shark, swordfish, tilefish, and king mackerel (8, 9).

Regardless of muscle mass and physique goals, those who are physically active need more protein than those who are sedentary. This includes people with active jobs, all the way to endurance athletes.

Older adults have significantly increased protein needs as well — up to 50% higher than the DRI, or about 0.45–0.6 grams per pound (1–1.3 grams per kg) of body weight (10)

This can help prevent osteoporosis and sarcopenia, both of which are significant problems among older adults.

Summary

People who are physically active, as well as older adults and those recovering from injuries, have significantly increased protein requirements.

Some research suggests casual links between high protein diets and kidney function impairments. However, there is no evidence to suggest a direct cause and effect between the two. However, further research has shown that following a high-protein diet can aggravate preexisting chronic kidney disease (11, 12).

As a result, people with preexisting kidney conditions should consult their doctor or other healthcare professional before drastically changing their protein intake (13).

Overall, there’s no evidence that a reasonably high protein intake has any adverse effects in healthy people trying to optimize their health.

Summary

Protein does not have any negative effects on kidney function in healthy people, and studies show that it leads to improved bone health.

There is a broad range of foods that are high in protein. These include:

However, most people generally don’t need to track their protein intake.

If you’re healthy and trying to stay that way, simply eating quality protein sources with most of your meals, along with nutritious plant foods, should bring your intake to an optimal range.

This is a very common area of misunderstanding.

In nutrition science, “grams of protein” refers to the number of grams of the macronutrient protein, not the number of grams of a protein-containing food like meat or eggs.

An 8-ounce serving of beef weighs 226 g but only contains 61 g of protein. Similarly, a large egg weighs 46 g but only packs 6 g of protein.

If you’re at a moderate weight and don’t lift weights regularly, protein should constitute 10–35% of your daily calorie needs. However, different people require different amounts depending on their activity level, weight, age, sex, and health status (1).

The U.S. adult should typically consume around

  • 34–56 g per day for the average male
  • 34–46 g per day for the average female

Still, given that there’s no evidence of harm and significant evidence of benefit, it’s likely better for most people to err on the side of consuming more protein rather than less.

Protein is essential for good health. It plays a vital role in muscle and bone strength, immune support, and cellular function.

A typical U.S adult should consumer around 50 g of dietary protein per day. However, this number will vary depending on a person’s age, sex, health status, and activity levels.