There’s lately been a preoccupation — verging on an obsession — with getting enough protein. And it’s no wonder, given that, compared with carbohydrates and fats, proteins are the most filling macronutrient, which are the nutrients your body needs in the largest amounts.
Proteins are present in every cell of the body and are considered the building blocks of life. They’re not just another energy source, like fat and carbohydrates, however. Protein plays a vital role in building and repairing our muscles and organs, and our bodies need 20 types to function properly — nine of which are essential and must come from food sources.
Knowing how much protein to eat every day and what are the best sources is crucial for maintaining overall health. How much protein do you need and does that change as you age? And is there such a thing as too much protein? Let’s break it down.
How much protein to eat per day, based on your age
In its 2020-2025 USDA Dietary Guidelines for Americans, here’s what the USDA recommends for daily protein intake based on age and sex :
Infants (6-11 months): 11 grams
Toddlers (1-3 years): 13 grams
Children (4-8 years): 19 grams
Children (9-13 years): 34 grams
Teen/adult females (14+ years): 46 grams
Teen males (14-18 years) 52 grams
Adult males (19+ years): 56 grams
Pregnant/lactating people: 71 grams
To put that into perspective, one hard-boiled egg contains about 6 grams of protein, while 3 ounces of chicken — about the size of a deck of cards — has around 23-26 grams of protein. According to Harvard Medical School, a female teen or woman, for example, can get 46 grams of protein by eating one serving of low-fat Greek yogurt, a 4-oz. serving of lean chicken breast and a bowl of cereal with skim milk.
How much protein do you need?
Determining the right amount of protein is a bit complicated, however. That’s because there’s ongoing debate about how much protein a person actually needs. The recommended dietary allowance (RDA) for the average adult is 0.8 grams of protein per kilogram of body weight (or about 10% and 35% of your total calories from protein). But that’s for a sedentary adult and is the minimum — not the optimal — amount to prevent losing lean body mass, aka muscle. So, if for example you’re 65 and older and weigh 165 pounds (about 75 kilograms), you’ll want to eat a minimum of 60 grams of protein daily, according to the Mayo Clinic.
However, the RDA is frequently used as the exact amount of protein you might need and doesn’t consider factors like age, sex, health status, how active you are and medical conditions, such as illness, surgery recovery and pregnancy, which require more protein.
Newer research suggests that most adults have higher daily protein needs than that — about 1.3-1.8 grams per kilogram of body weight — and that the government’s recommendations are too low.
For building and maintaining muscle mass, The International Society of Sports Nutrition (ISSN) recommends even more: 1.4-2.0 grams of protein per kilogram of body weight per day. So for a 150-pound person, this translates to about 89-123 grams of protein daily, or 95-136 grams if prioritizing muscle growth. It’s possible that the current protein recommendations for children are also too low, but more research is needed on that front.
For those recovering from pregnancy and breastfeeding, the American Pregnancy Association suggests at least 75-100 grams of protein per day.
For adults 65 and up, recent research recommends consuming at least 1.2 grams of protein per kilogram of body weight to combat sarcopenia, the natural loss of muscle that comes with aging. Postmenopausal women, in particular, may be at greater risk of developing the condition because of lowered estrogen levels.
Can you eat too much protein?
While protein is crucial for life, our bodies can only efficiently use a certain amount in one sitting and can’t store excess protein. Even though there’s no fixed limit, some research suggests a max of 20-40 grams of protein per serving for athletes, who typically consume more protein than most. Having more than this amount per serving means excess protein is used for energy or stored as fat.
Consuming too much protein can be harmful. It can crowd out other vital nutrients from your diet, like healthy fats, fiber and carbohydrates. Regularly overeating protein can also lead to digestive issues, nausea, headaches, dehydration, kidney stones and reduced energy levels. And it increases the risk for heart, liver and kidney disease.
It’s important to be cautious with protein intake over 2 grams per kilogram of body weight. I always encourage people to work with their health care providers, specifically a registered dietitian, to help determine your individual protein and nutrient needs.
Where should I get protein from?
As with most nutrients, variety is key when it comes to protein. As a dietitian, I recommend getting most of your protein from lean sources, which can include both animal and plant-based options.
Animal proteins provide all of the essential amino acids, and include poultry like chicken or turkey, red meat like beef and pork, as well as fish, seafood, eggs and dairy. Some plant-based proteins, such as quinoa, soybeans, chia seeds and hemp seeds, also offer all nine of the essential amino acids. However, other plant-based proteins, like nuts, beans and wheat, are missing at least one or more essential nutrients, so it’s important to consume a variety of these to ensure your diet is complete.
If you prefer animal sources of protein, keep in mind that they contain saturated fats, and eating too much can lead to high LDL (bad) cholesterol, heart disease and stroke. Generally speaking, ultra-processed meats like hot dogs, sausages and chicken nuggets are often higher in saturated fat and sodium. Not to mention, excessive consumption of red meat has been linked to a higher risk of colon cancer.
On the plus side, animal proteins provide certain nutrients not found in plant-based sources — for instance, vitamin B12, found in red meat, poultry, dairy, eggs and fish, supports nervous system function. And heme iron, present in meat, poultry and fish, is more easily absorbed by the body than non-heme iron, found in plant-based proteins like beans and spinach.
Plant-based proteins, on the other hand, are an excellent choice for those looking to reduce their intake of animal products or are following a vegetarian or vegan diet. Unlike animal proteins, plant-based proteins typically come with fiber and are beneficial for heart health. Whole grains, in particular, pack more protein and fiber than refined grains.
Aim to get most of your protein from food sources first, but if you struggle to do that, a protein supplement, such as protein powder you can add to smoothies, are a helpful addition too.
Maxine Yeung is a dietitian and board-certified health and wellness coach.
