There is a lot of hype surrounding protein these days. The market is flooded with a variety of protein supplements for different age groups and activity levels, promising everything from boosting metabolism to building bigger muscles.
Protein intake, from natural food sources, as well as, from the addition of protein supplements to your diet, offer a multitude of health benefits. Adequate intake of high-quality protein does help boost your weight loss efforts and to build lean muscle mass. But how much protein do you really need to take to achieve these benefits?
There is no one dosage that fits all. The protein needs of a person differ based on various factors such as age, activity levels, fitness goals, etc. To find out how much protein you need to take, it’s vital to be aware of why you are taking it in the first place.
The Importance of Protein in Diet
Along with fat and carbohydrates, protein ranks among the three main macronutrients required by the human body. They not only form the primary building blocks of human tissue, but they are also a source of fuel for you.
Protein is one of the most important components of every cell that is present in the human body. Protein is used to create and repair tissues, to build bones, tendons, cartilage, skin, and blood. They are needed for the growth of muscles, and to produce enzymes, neurotransmitters, and hormones. Even our hair and nails are made of proteins.
Proteins are made up of units called amino acids. While some of these amino acids are produced in our body others, known as the essential amino acids have to be obtained from our diet. A protein food source that contains all the 9 essential amino acids are called complete proteins foods.
How Much Protein Should I Eat?
For nearly 100 years, dietary protein recommendations have been in the making and they are still on. But the answer to the simple question is still unclear.
An essential portion of your body’s composition is made of protein, and it is crucial in growth and development. Moreover, dietary protein is needed throughout life to replenish the irreversibly oxidized amino acids which the body can’t synthesize.
The recommendation of this macronutrient in the United States comes from the Food and Nutrition Board (FNB) of the Institute of Medicine. The values that have been derived are the Estimated Average Requirement (EAR), the RDA (Recommended Dietary Allowance), and the Tolerable Upper Intake Level (UL) (1).
Currently, the EAR and RDA of protein are 0.66 grams/kg body weight/day and 0.80gms /kg of body weight/day. This equates for men and women aged 19-50 years respectively. The UL has been confirmed to be 3.5 gms/kg body weight/ day.
This recommendation is not ideal but means “the minimum quantity to avoid malnutrition”. It was based on nitrogen balance studies that required people to take experimental diets for weeks before measurements were noted (2).
But, these value changes depending on sex, body weight, lean body mass, activity level, and other factors. There is an extra requirement for growth in infants and children and for pregnant and breastfeeding women (3). It also changes depending on the health or fitness goals, such as weight loss, weight gain, bodybuilding, etc.
In addition to the parameters that have been mentioned above, the recommendation for macronutrient intake is also given in context to the percentage of the total calorie intake. It is known as AMDR, Acceptable Macronutrient Distribution Range. It has been estimated that 10-35 percent of calorie intake should come from protein (4).
Various Circumstances that Increase your Protein Needs
Infants And Toddlers
Infants should consume at least 9.1 grams of protein each day (5). 11 grams per day should be for infants whose ages are in the range of 6 to 12 months (6). For toddlers, the intake increases to 13 grams.
A preterm child would require 4.0 g/kg per day to catch up with growth (7).
Children in the age group of 4 to 13 years require an RDA of 0.95 g/kg as compared to an adult whose RDA is 0.8 g/kg of body weight (8). Children need more protein as they are still growing.
Protein is needed to build and repair cells, enzymes and hormones and whenever required to produce energy. Protein helps form the new blood cells and tissues in the body of the growing child. However, the RDA is not enough for the needs of children who are involved in sports and athletic activities are much higher.
Active Adult and Athletes
More protein is needed for a physically active person than for one who leads a sedentary life. The recovery from sporting activities, to repair and rebuild muscles that have broken down while exercising and help in the optimization of carbohydrate storage as glycogen, will need more protein.
The Academy of Nutrition and Dietetics, Dietitians of Canada and the American College of Sports Medicine have provided certain guidelines for the type, amount and timing of food intake, supplements and also fluids (9).
- 1.2 to 2.0 g/kg is the recommendation for ideal recovery from training and for the growth of lean mass with sufficient calorie intake
- 1.6 g/kg is the average amount needed for lean mass (10)
Some people may require up to 2.2 g/kg. It would be better to go for the higher end of the recommended range.
The amount of protein recommended dietary allowance (RDA) of 1.1 g/kg was arrived at taking into consideration 3 values:-
- The RDA for a healthy adult
- The quantity of extra proteins a pregnant woman takes
- The quantity of protein that is being used by the developing fetus.
In accordance with a study done in 2015 to determine the protein requirement of pregnant women at the early (11 to 20 weeks) and the late (31 to 38 weeks) gestation periods using the amino acid oxidation method indicator (11) it was concluded that:
- 1.1 g/kg is the recommended dietary allowance
- 1.66 g/kg is the estimated average requirement for 11-20 weeks
- 1.77 g/kg is the estimated average requirement for 32 to 28 weeks
These estimates are considerably higher than the known estimated average requirement of pregnant women as noted by the RDI.
Protein is the building block of new tissues and is required for growth. Adequate protein is crucial to ensure the body can build, repair and maintain tissues and organs. It is particularly important for lactating mothers who are recuperating as well as helping the baby grow.
In accordance with the Dietary Guidelines for Americans, lactating mothers need 65 grams of protein per day.
Vegans And Vegetarians
The recommendation for protein intake for an adult male vegan is 63 grams per day and that for an adult female vegan is 52 grams per day. It is easy for a vegan diet to meet the requirement by making sure that the right food is included.
Some of the great protein-rich vegan foods are tofu, tempeh, edamame, lentils, nutritional yeast, hempseed, green peas, seitan (wheat gluten).
Protein Needs for Recovery From Injuries
Balanced nutrition negates the impact of injuries caused by intensive training. However, the severity of the injury can show different results (12).
A protein intake as high as 2 to 2.5 grams per kilogram of body weight taken every day will be required. Muscle protein synthesis reduces and therefore it is important that the amount of this nutrient is not decreased.
Protein Needs for People Suffering From Muscle Wasting
Malnutrition and muscle wasting are commonly seen in catabolic chronic diseases like diabetes mellitus, HIV infection, AIDS, cancer, and liver diseases, which are associated with impaired protein balance. In these diseases, the protein breakdown is more than the protein synthesis in the body, resulting in a negative balance.
The largest reservoir of protein in the body is the skeletal muscles. With a negative balance, muscle wasting takes place, leading to weakness, disability, and impaired quality of life. A significant clinical condition associated with chronic diseases like HIV, cancer and chronic pulmonary disease is muscle wasting (cachexia) (13).
Timely intervention to recognize this condition is necessary even while the underlying condition is being treated. Providing amino acids and energy (through outside sources) will help in increasing net protein synthesis.
Studies have confirmed that energy requirement increases by 10 percent in asymptomatic HIV positive adults and 20-30 percent in symptomatic HIV and AIDs adults.
For children with these diseases, who are experiencing weight loss, the energy requirement increases by 50-100 percent. However, data are insufficient to support an increase in protein requirements during HIV infection. But 12-15 percent of the total energy should come from protein, which is highly recommended.
5 Great Reasons to Optimize our Protein Intake
Increases Muscle and Strength
Eating adequate amounts of protein helps in the maintenance of your muscle mass. It also promotes muscle growth while you are doing strength training.
Many studies have stated the fact that eating a good amount of protein can help increase muscle mass, muscle endurance, lowering of the recovery period after intensive training, reduce fatigue, improve sprint ability and endurance.
The intake of protein supplements by active and serious athletes are common. The goal is to improve performance and gain muscle mass and strength.
The objective of a study that was taken up in 2015 was to evaluate the presumption that protein diets speed up muscle growth and strength (14).
Measures of body composition, aerobic and anaerobic power were considered.
Participants were trained and untrained individuals. The intensity, duration, frequency of the exercises along with the type and timing of protein supplementation were included.
It was observed that the protein diet had no impact on all these factors in untrained participants in the beginning. But, as the training gained momentum, protein supplementation caused muscle growth in both categories. It increased the power of the exercises.
Summary: This indicates that protein may promote muscle increase and exercise outcomes when training is higher in duration, volume, and frequency.
Good for Your Bones
Sufficient nutrition is necessary for the development and sustainability of bones. Along with calcium and regular intake of vitamin D rich food, dietary proteins have also an important role especially in the prevention of bone diseases like osteoporosis.
A study taken up in 2011 that included postmenopausal women recorded a marked reduction in the number of hip fractures due to protein supplementation (15).
The other benefits were:
- Reduced risks of post-fracture bone loss
- A gain in muscle strength
- Decreased medical complications
- Decreased rehabilitation hospital stay
However, high-protein diets, with intake higher than 2.0 grams/kg of body weight per day, should be avoided when the calcium intake is less than 600 mg per day.
Summary: The study indicated that a high-protein diet up to 2.0 grams/kg of body weight per day may help in positively impacting the number of hip fractures among postmenopausal women.
The recommended dietary allowance of only 0.8 grams/kg of body weight in a day is far too low to prevent this injury as a first or second incident.
Aids Fat Loss
High protein diets are becoming increasingly popular for its twin benefits. One is its ability to improve satiety and the other one is to decrease fat mass.
The potential mechanisms that are responsible for weight loss are its involvement in increased secretion of satiety hormones (GLP-1), peptide YY, and cholecystokinin. It also reduces the secretion of ghrelin ( the hunger hormone).
A review of studies that conducted trials confirmed better feelings of fullness and higher satiety hormone after a high protein diet meal (16).
Summary: Short term high protein diet benefits better by not only aiding in better weight management but also improves overall health by lowering blood pressure, triglycerides and assisting in fat mass loss.
A higher metabolic rate may help those who are overweight and physically active people. The World Health Organization has advised that 0.8 to 0.83 grams of protein per kilogram of body weight is needed for nitrogen balance for all people (17).
The digestibility and bioavailability of protein and its amino acids determine the extent of benefits it can deliver. The high thermic effect (makes you burn more calories) of proteins is considered to be high and therefore influences the metabolic rate (18).
A high-protein diet raises the level of energy expenditure. Whey and casein proteins can be added to your diet to increase the overall protein uptake. They have high digestibility and also supply essential amino acids.
Summary: The thermogenesis caused by a high-protein diet induces a higher metabolic rate and also increases the level of satiety.
Reduces Appetite and Hunger
High-protein diets have been studied to cause weight loss (19). It increases the process of thermogenesis or expenditure of energy during metabolism.
Studies have indicated how a high-protein intake increases the level of satiety hormones in the body and at the same time decreases the level of ghrelin, the hunger hormone in the body (20).
Summary: A high-protein diet makes a person feel fuller for a longer period of time. As the hunger hormone subsides and satiety hormones are released, it positively affects the weight of the person making way for healthy weight loss.
Side Effects of High Protein Intake
The trend for a high protein diet is increasing day by day and it has been shown to be helpful in reducing fat, losing weight, increasing satiety, and retaining muscle.
However, it is also associated with several risk factors that we need to be aware of. Hence, the nutritional experts don’t really advocate exceeding your protein intake way above the recommended limit.
The side effects which are normally seen with very high intake of food are:
- Bad breath
- Weight gain
- Digestive problems such as constipation, also diarrhea,
- Kidney damage
- Increased cancer risk
- Heart Disease
- Calcium loss
Commercial protein sources, that are available in the market, are protein supplements with whey protein, soy protein isolate, calcium caseinate, egg white, pea protein isolate and so on. When taken in exceedingly high amounts, it may cause nausea, increased thirst, bloating, cramps, reduced appetite, fatigue, and increased bowel movements.
Best Sources of Protein
While choosing a food that is high in protein, it is better to select healthier options. This can very well help lower your risk of the negative effects of a high-protein diet. Healthy sources of proteins are:
- Eggs from pastured hens
- Wild fish
- Grass-fed lean meats and pasture-raised poultry
- Grass-fed organic dairy and dairy products like cottage cheese
- Whole grains and healthy grains like oats
- Nuts like almonds, pistachios, peanut, and cashews
- Legumes like soybean, kidney beans, and chickpeas.
- Vegetables like broccoli, Brussel sprouts,
- Pseudo cereal like quinoa
- Whey protein supplements
Nuts and seeds are good sources of protein and fiber. They make for nutritious salads and snacks. Beans and peas also fall in the same category (21).
Tofu and soy foods are a good alternative to animal proteins. Check out for non-GMO varieties. These foods are high in protein and low in fat.
Healthy proteins can be derived from milk and milk products like cheese and yogurt. Processed food products could have added sugar. Processed cheese at times contains non-dairy substances.
Fish is known to have high protein and low saturated fat content. Salmon, sardines, sablefish, and herring are rich in omega-3 fatty acid food. A fish food intake twice a week has been recommended by experts.
Frequently Asked Questions
How Much of Your Daily Intake of Energy Should Come From Proteins?
In a healthy diet, 10 to 35 percent of your daily calories should come from protein. Protein is crucial for growth, maintenance, and energy.
It can be stored and is done usually in the muscles. It promotes the feeling of fullness, spares muscle loss and has the highest thermic effect amongst all the macronutrients (22).
Why Do Men Need More Protein Than Women?
Men need more protein than women for the simple reason that they have a larger lean body mass. However, differences in diet, age, lifestyle, metabolism in total play an important factor in determining the healthy daily protein intake (23).
How Does my Activity Level Affect my Protein Needs?
Energy gets released with exercise and physical activity. Amino acids in proteins are oxidized at the time of training especially in endurance and resistance forms of training (24), (25). This brings about the breakdown and synthesis of proteins.
Scientific evidence has shown that those engaged in regular exercise have higher protein needs. Athletes require proteins to enhance strength and performance.
Timing and nutritional content play an important role for those involved in physical activities. Post-workout recovery diets are rich in amino acids and carbs that are needed for replenishment and muscle building.
What Factors Influence my Protein Needs?
Carbohydrates are one of the main factors to decide the proteins you consume (26). carbohydrates are anabolic in nature and are protein sparing. This means that if your diet is high in carbohydrates, less protein is needed by your body, and vice-versa.
This helps retain a positive nitrogen balance. As the body stores glycogen for its fuel need, it spares amino acids for muscle recovery and growth.
Those with naturally high levels of testosterone utilize more protein thereby increasing your protein requirement. This will ensure more muscle protein synthesis. If your training volume increases to a great extent, more protein is required to support the activity as well as recovery post-exercise.
The next factor that is necessary for proteins to be effective is your gut health. Proper muscle protein synthesis takes place when your gut is free from any gastrointestinal disorders.
The quality of protein will also determine protein intake. If you have a complete protein with all the required amino acids, a lesser amount should be effective in comparison to the proteins sourced from vegetables.
Are Protein Snacks Good for You?
Yes, protein-rich snacks are good for your body. In a busy lifestyle, not only do they curb the hunger pangs but also ensure that the food that goes inside your body is nutritious and contains the desired macronutrients.
The protein in it promotes fullness as it signals the appetite-suppressing hormones, resists spike in blood sugar levels and slow digestion.
What is a Good Protein Snack?
Some of the good protein snacks are the ones that provide you with 8-15 grams of protein. In case, it is over 20 grams of the macronutrient, all of it will not be absorbed. It is better to aim snacks with less than 15 grams of sugar and some fiber.
A few of them are the trail mix, Greek yogurt parfait, turkey roll-ups, peanut butter celery sticks, veggies, and yogurt dip. Commercial protein snack packs have flooded the market and with guidance from your dietitian, you can go for the right one.
The Final Note
Intake of sufficient protein is important for the proper functioning of your body and physical activities.
The importance of this macronutrient is seen from its requirement for the growth of a child from its infancy. Pregnant and lactating women require more of this nutrient even as their bodies supply nourishment to the unborn or newborn child.
If you wish to lose weight and build muscles then protein becomes the central nutrient around which you can build your diet and exercise program. Consulting your dietitian will guide you on the right sources of protein for your body type and composition.
Consuming a well-balanced diet will supply proteins and all other nutrients needed. Choose food sources that deliver the essential amino acids of proteins. Supplemental protein foods can make up for any nutritional gaps that may not be available in your natural food diet. Engaging in physical activities will make the best use of proteins to keep your body fit and healthy.