There are several factors that determine your optimal daily protein NEEDS. These are: your weight, your goal (weight maintenance, muscle gain, or fat loss), the amount of physical activity you have, and whether you’re pregnant or not.
Our analysis was corroborated by peer-reviewed scientific papers.

Seeing how nutrition is a very complex subject, there isn’t really a simple answer to this question. There are numerous factors that should be considered, such as your health, body composition, the main goal, and the type, intensity, duration, and frequency of your physical activity. Even with all of these questions answered, you will get a starting number. After some self-experimentation, you will be able to adapt this number to fit your physique.
In case you didn’t know, daily protein requirements are usually expressed in grams, either per kilogram of body weight (g/kg) or per pound of body weight (g/lb). These numbers vary depending on individual variances.

Here is a list of optimal daily protein for adults:

Sedentary adults should aim for 1.2–1.8 g/kg (0.54–0.82 g/lb). Remember that adding regular activity will lead to the improvement of your body composition. A good example is resistance training.

If you are an active individual with a healthy weight, and you want to maintain your current weight, you should aim for 1.4–2.0 g/kg (0.64–0.91 g/lb). You should aim for the higher end of this range if you are trying to keep the same weight but improve your body composition (have more muscle and less fat).

People who want to build muscle but are otherwise of healthy weight and active should strive for 1.6–2.4 g/kg (0.73–1.10 g/lb). Intakes as high as 3.3 g/kg can significantly help experienced lifters who are looking to minimize fat gain when bulking.

People who want to lose fat but are otherwise of healthy weight and active should strive for 1.6–2.4 g/kg (0.73–1.10 g/lb). Aim toward the higher end of this range as you become leaner or if you increase your caloric deficit (by eating less or exercising more). Lean lifters who take as high as 3.1 g/kg can lose fat and minimize muscle loss.

People who are obese and overweight should aim for 1.2–1.5 g/kg (0.54–0.68 g/lb). This range depends on your total body weight (the majority of studies on people who are obese report their findings based on total body weight, but you’ll find some calculators that determine your optimal protein intake based on your lean mass or your ideal body weight).
Pregnant women should aim for 1.7–1.8 g/kg (0.77–0.82 g/lb).

Women who are lactating should aim for at least 1.5 g/kg (0.68 g/lb).

Vegans and people who obtain most of their protein from plants should have higher protein requirements. The reason for this is that plant-based proteins are usually inferior to animal-based proteins when it comes to bioavailability and amino acid profile.

You should keep in mind that protein intake should be based on body weight, not on caloric intake. (These two are linked since caloric intake should be based on body weight)
Most of the studies have examined dosages up to 1.5 g/kg and only a few have looked at dosages as high as 2.2–3.3 g/kg. But the higher dosages have shown not to have any negative side effects on healthy people.

How To Calculate Your Caloric Needs?

When it comes to calculating your caloric needs, your height, weight, age, and level of physical activity play the main role. You can find numerous caloric calculators online, but the NIH Body Weight Planner is regarded as one of the most proficient. Professional nutritionists have tested it and validated against real-world data, therefore it can efficiently calculate the number of calories you need to reach, and then maintain a specific weight.

When it comes to calories, there are three types of diets you can apply:

A hypocaloric diet suggests that you should take fewer calories than you burn per day. If you are someone who is keen on losing weight, then this is the diet you should start. If you want to lose weight by only burning fat, not losing any muscle, then you’ll also need to consume enough protein and it is recommended that you exercise daily.

A hypercaloric diet means that you should eat more calories than you burn. This diet is for people who are looking to gain weight. If you want the weight you gain to be in the form of muscle, not fat, then you’ll need to get the right amount of protein and start practicing resistance training (lifting weights is a good example).

A eucaloric diet means that you should consume as many calories as you burn. This diet is also called a maintenance diet since your weight stays mostly the same. Although, depending on how much protein you take and how regularly you exercise, you can gain or lose fat or muscle.

Are You a Healthy and Sedentary Adult? These Are Your Recommended Daily Protein Needs

While the study by the Institute of Medicine,”10 Protein and Amino Acids” has stated that, for adults, the US Recommended Dietary Allowance (RDA) for protein is 0.8 g/kg, there is a more appropriate statistical analysis of the data used to establish the RDA. As the study by Elango R, et al. called “Evidence that protein requirements have been significantly underestimated.” has shown us, this number should be higher: 1.0 g/kg.
Keep in mind that, unlike the popular opinion, the RDA doesn’t actually show the ideal protein intake. Instead, it represents the minimum intake that a human body needs so it doesn’t starve. However, the RDA for protein was decided by organizing nitrogen balance studies. These studies require the participants to try out experimental diets for weeks before the measurements are taken. By doing this, the study by Young VR and Marchini JS. “Mechanisms and nutritional significance of metabolic responses to altered intakes of protein and amino acids, with reference to nutritional adaptation in humans” has shown that the human body had enough time to adapt to these low protein intakes by down-regulating processes that are not necessary for survival but are necessary for optimal health, such as protein turnover and immune function.

There are a few other methods used for figuring out protein requirements, but one of the most popular is called the Indicator Amino Acid Oxidation (IAAO) technique. This technique overcomes most of the nitrogen balance studies drawbacks. Markedly, it allows for the assessment of protein requirements within 24 hours, thereby not leaving the body enough time to adapt. Studies that have used this IAAO method have come to the conclusion that about 1.2 g/kg is a more appropriate RDA for healthy young men, older men, and older women.

There is additional evidence that the current RDA for protein is not valid. This evidence comes from a randomized controlled trial that had healthy, sedentary adult participants that were placed in a metabolic ward for eight weeks. The participants were randomized into three groups that used a different type of hypercaloric diet. Each diet was equally hypercaloric and each participant consumed 40% more calories than needed to maintain their current weight. Although the study has shown that eating near the RDA for protein has resulted in a loss of lean mass. While this loss was quite small and insignificant, the higher protein intakes were believed to contribute to the increase in lean mass.

There has been one more thing that nutritionists learned from this study. Eating more than 1.8 g/kg doesn’t drastically benefit your body composition. So in case you aren’t physically active or trying to lose some weight, this number makes a good higher end for your daily protein intake.

Sedentary Adults Protein Intake Summary

Many nutritionists suggest that the RDA for protein (0.8 g/kg) doesn’t adequately estimate the needs of healthy, sedentary adults. Rather, they should aim for 1.2–1.8 g/kg (0.54–0.82 g/lb).

Are You an Athlete? These Are Your Recommended Daily Protein Needs

If you are an athlete or someone who is physically active on a daily basis, then your body needs more protein daily than a sedentary adult. Professionals that work within The American College of Sports Medicine, the Academy of Nutrition and Dietetics, and the Dietitians of Canada have done a lot of research and came to a conclusion.

For athletes the recommend protein dosage is 1.2–2.0 g/kg.

With this amount, the body can recover from training more efficiently, and the growth and maintenance of lean mass when caloric intake is sufficient can be enhanced. The International Society of Sports Nutrition (ISSN) also has a similar recommendation for the daily intake: 1.4–2.0 g/kg.

Nutritionists suggest that it might be more beneficial to go for the higher end of the above ranges. The most complete meta-analysis that has been done, the study by Morton RW “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” suggests that when it comes to the effects of protein supplementation on muscle mass and strength, the average amount of protein required to maximize lean mass is about 1.6 g/kg, and some people need upwards of 2.2 g/kg.

On the other hand, out of 49 included studies, only 4 were conducted in people with resistance training experience (The 45 other people were newbies). IAAO studies in athletes had some different results. Female athletes required 1.4–1.7 g/kg the day after a regular training session during their training days, while male athletes required even up to 2.1–2.7 g/kg. When it comes to amateur male bodybuilders, two days after their last resistance-training session, their body required 1.7–2.2 g/kg.

Scientists have come to the conclusion that higher protein absorptions seem to have no negative effects on healthy people. Actually, you may even want to aim toward the higher amounts. For most athletes, and regularly active adults, the ISSN range of 1.4–2.0 g/kg should be just enough.

Recommended Protein Intake For Athletes Summary

A daily protein intake of 1.4–2.0 g/kg (0.64–0.91 g/lb) is enough for athletes and similarly active adults who want to optimize their body composition, performance, and it is recommended that they strive toward the upper end of this range.

Do You Want to Gain Muscle? These Are Your Recommended Daily Protein Needs

Resistance training, such as lifting weights, using weight machines, weight balls, is a key factor when you are trying to gain muscle. It’s not enough that you feed your muscles with things that they need to grow you also need to do a few other things so they have a reason to grow.

The study by Antonio J. ”The effects of consuming a high protein diet (4.4 g/kg/d) on body composition in resistance-trained individuals” has shown that in order to gain muscle, most people should aim for 1.6–2.4 g/kg of protein per day.

If you are doing resistance training and are on a moderate hypercaloric diet (370–800 kcal above maintenance), nutritionists have done some research and came to the conclusion that you will gain less fat if you eat more protein (3.3 g/kg rather than 1.6–2.4 g/kg). Although, there are a few cases where this hasn’t turned out to be true.

One of the most important things to remember is that if you take 3.3 g/kg of protein daily, the chances of you building more muscle than when you are taking 1.6–2.4 g/kg of protein aren’t much higher. The higher number can help you in minimizing fat gains that you might experience if you eat above maintenance in order to gain (muscle) weight. The hypercaloric diet intakes that go as high as 3.3 g/kg are usually most beneficial to weight lifters that minimize fat gain while bulking.

Recommended Protein Intake For Muscle Gain Summary

As we have mentioned, athletes and active adults can optimize muscle gain with a daily protein intake of 1.6–2.4 g/kg (0.73–1.10 g/lb). But when it comes to experienced lifters on a bulk, up to 3.3 g/kg (1.50 g/lb) can help them minimize their fat gain.

Do You Want to Lose Fat? These Are Your Recommended Daily Protein Needs

Firstly, it’s important to know that, contrary to popular opinion, it is possible to lose fat on a eucaloric diet (aka maintenance diet that provides as many calories as you burn) if you start shifting your macronutrient ratios toward getting more protein. But, if you want to keep losing weight you’ll need to switch to a hypocaloric diet (This means that you should eat fewer calories than you burn).

High protein intakes can help in preserving lean mass in dieters, especially lean dieters. Dieting athletes (Those on a hypocaloric diet) who want to optimize their body composition should consume 1.6–2.4 g/kg and should aim for the higher end of this range as they become leaner. They should also lean toward the higher end if they increase their caloric deficit (by eating less or exercising more).

Later studies, done by Helms ER “A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: a case for higher intakes” have shown that to minimize lean-mass loss, dieting lean resistance-trained athletes should consume 2.3–3.1 g/kg (closer to the higher end of the range as leanness and caloric deficit increase). The International Society of Sports Nutrition (ISSN) has supported this latter recommendation and has done an interesting review article on bodybuilding contest preparation.

A few meta-analyses that have involved people with that are overweight or obese suggest that 1.2–1.5 g/kg is an appropriate daily protein intake range to maximize fat loss. The European Association for the Study of Obesity has also supported this claim, which recommends up to 1.5 g/kg for elderly adults that struggle with obesity. Keep in mind that this range is based on actual body weight, and not on lean mass or ideal body weight.

When someone is obese and overweight, there are certain health risks that come with it. It is very important to remember that maintaining a diet where you have a higher protein intake (27% vs. 18% of calories) can help reduces several cardiometabolic risk factors. Some of these include waist circumference, blood pressure, and triglycerides, while also increasing satiety. The effects of this diet may not be very significant, but it all depends on the amount of body fat that you lose.

Remember, if you’re overweight or obese, you should make fat loss your priority, but that doesn’t mean that you can’t work on building some muscle at the same time.

Recommended Daily Protein Intake For Fat Loss Summary

Athletes and other active adults who are on a certain diet aiming to lose fat are most likely already lean. They can maximize fat loss and muscle retention with a daily protein intake of 1.6–2.4 g/kg (0.73–1.10 g/lb). People who are overweight or obese, on the other hand, should aim for an intake of 1.2–1.5 g/kg (0.54–0.68 g/lb).

Exploring Further: Why Should Athletes Consume More Protein?

It’s no secret that athletes that are on a diet benefit from higher protein intakes, depending on their weight, than compared to individuals who are overweight and obese. If you are wondering why this is, there are three common explanations:

People who are overweight and obese often have stagnant metabolisms. This means that their metabolism is used to storing fat over protein (protein being stored as muscle). More often than not, they need a higher caloric deficit to lose fat than compared to athletes. This rule doesn’t always apply, because the closer an athlete gets to their essential body fat, the harder it can be for them to lose fat.

How much protein you should consume depends on your total weight. For example, let’s imagine we have two dieters who have the same weight. If one of them is already a lean athlete and the other one is obese, the latter will get to consume a lot fewer calories. If an athlete is consuming 3,000 kcal and 180 grams of protein (720 kcal) daily, then his diet is 24% protein. On the other hand, if an overweight individual consumes 2,000 kcal and 120 grams of protein (480 kcal) then his diet is also 24% protein.
If you have a lean athlete and an overweight person who have the same weight, the athlete needs more protein to maintain their muscle mass, since they already have more muscle than the other.

We hope this article helped you gain some knowledge about how the daily intake of protein varies between different groups. If you were struggling with figuring out your own daily dose, remember to take into consideration all of the factors that we have mentioned and follow the dosages that we have researched.