Protein is an essential nutrient; its consumption is essential for the health of your muscles and cardiovascular health. Eating protein can also help you manage certain diseases and even support your weight-loss efforts. The amount of protein you should consume is based on your weight, physical activity, age and other factors.
The RDA for Protein
The Recommended Dietary Allowance, or RDA, for protein is based on your weight. Most people should consume 0.8 gram of protein per kilogram of body weight. However, factors such as whether you're an athlete or are pregnant can also play a role in your protein intake.
People can consume 2 grams of protein per kilogram of body weight long term without issues. However, according to a 2016 review article in the Journal of Food Functionality, the tolerable limit of protein consumption is 3.5 grams per kilogram of body weight: more than four times as much as the standard RDA for protein. Excessive protein intake over the long term may affect digestive, kidney or vascular health.
Calculating the RDA for Protein
To find out how much protein you should be consuming, take your weight, which you probably know in pounds, and convert it to kilograms. The average American man weighs 195.7 pounds (the equivalent of 88.77 kilograms), while the average American woman weighs 168.5 pounds (which equals about 75.21 kilograms).
Since most people should consume 0.8 gram of protein per kilogram of body weight, this means that the RDA formula is:
(0.8 gram of protein) x (weight in kilograms)
Given this guideline, most men should consume about 71 grams of protein per day, because 0.8 x 88.77 = 71.016. Women should typically consume about 60 grams of protein per day, since 0.8 x 75.21 = 60.168.
If you're having trouble calculating your body weight in kilograms, you can also just multiply your weight in pounds by 0.36 gram of protein. This would mean the RDA formula is:
(0.36 grams of protein) x (weight in pounds)
If you're not comfortable calculating your RDA for protein manually, there are a variety of protein intake calculators available online. For example, you can use websites like the United States Department of Agriculture's Dietary Reference Intakes Calculator.
People Who Need More Protein
Although the RDA for protein is typically 0.8 gram per kilogram of body weight, many people can consume more protein safely. Athletes, for instance, can consume up to double this amount of protein. Other people, like pregnant women, breastfeeding mothers and older adults also need to consume more of this nutrient.
The amount of protein you should consume as an athlete depends on the type of physical activity you engage in. In general, people performing regular exercise should consume:
- Minimum physical activity (occasional walk or stretching): 1.0 gram of protein per kilogram of body weight
- Moderate physical activity (regular weightlifting, brisk walking): 1.3 grams of protein per kilogram of body weight
- Intense physical activity (athletes, regular joggers): 1.6 grams of protein per kilogram of body weight
Pregnant women also need to consume more protein than average. According to a 2016 study in the Journal of Advances in Nutrition, women should consume between 1.2 and 1.52 grams of protein per kilogram of weight per day during pregnancy.
The lower amount (1.2 grams) is suitable for early pregnancies of about 16 weeks, while the upper amount is recommended for later pregnancies of about 36 weeks. Protein in pregnant women isn't only important for the growth of the developing fetus; it's also essential in helping the mother's body prepare to breastfeed her child.
Why Is Protein Important?
Consuming too little protein is bad for you. As an adult, you can experience problems such as anemia, weakness and fatigue, swelling, vascular and immune system issues, if you consume too little protein. If you're still growing, too little protein can stunt your growth. People following low-protein diets, vegans and vegetarians are the more likely than most to be consuming too little protein.
This doesn't mean you should eat as much protein as you can, though. Too much protein can be bad for you, as well. Protein consumption that surpasses 2 grams of protein per kilogram of body weight per day can cause vascular issues as well as problems with your digestive system and kidneys. People who adhere to high-protein diets or drink a large number of protein shakes may be the most likely to consume excessive amounts of protein.
Regardless of what type of diet you choose to follow, you should consume at least 5 percent protein. Less than this amount is too little to keep your body in good health and can lead to loss of muscle mass. Most people should consume diets that are about 12 to 20 percent protein.
Healthy Sources of Protein
Most people hear the word protein and immediately think meat. While products like beef, lamb, pork and chicken can all be good sources of protein, they're not your only alternatives. Fish and shellfish are also good sources. These marine creatures also contain omega-3 fatty acids, which are good for your heart, brain and immune system.
Vegetarians have access to a wide range of protein sources as well. Many vegetarians consume eggs and milk products, like yogurt and milk, which are rich in protein. Other common sources of vegetarian-friendly protein are beans, legumes, nuts, seeds, tofu and seitan. These plant-based proteins are all good choices for vegans too.
Certain fruits and vegetables, like avocado, spinach, corn and brussel sprouts, are also valuable sources of protein. Even fruits like lucuma, which can be processed into lucuma powder and used as a natural sweetener, can help provide you with protein. Lucuma has also been shown to help promote lactation in women after giving birth. This makes it a particularly beneficial food for pregnant women or nursing mothers who prefer plant-based sources of protein.
- MyFoodData: Top 10 Vegetables Highest in Protein
- Journal of Ethnobiology and Ethnomedicine: Medicinal Plants Used in Northern Peru for Reproductive Problems and Female Health
- Postharvest Biology and Technology of Tropical and Subtropical Fruits: Lucuma (Pouteria lucuma (Ruiz and Pav.) Kuntze)
- BBC Good Food: The Best Sources of Protein for Vegetarians
- NIH: Omega-3 Fatty Acids Fact Sheet for Health Professionals
- Kaiser Permanente: Balancing Carbs, Protein, and Fat
- Age and Aging: New Horizons: Dietary Protein, Ageing and the Okinawan Ratio
- Food Functionality: Dietary Protein Intake and Human Health.
- Advances in Nutrition: Protein and Amino Acid Requirements During Pregnancy
- International Journal for Vitamin and Nutrition Research: Protein Intake and Bone Health
- USDA: DRI Calculator for Healthcare Professionals
- Harvard Health Publishing: How Much Protein Do You Need Every Day?
- CDC: National Center for Health Statistics: Body Measurements
- Food and Nutrition Board: Dietary Reference Intakes (DRIs): Recommended Dietary Allowances and Adequate Intakes, Total Water and Macronutrients
- The American Journal of Clinical Nutrition: The Role of Protein in Weight Loss and Maintenance
- USDA's Nutrient Database