Protein has become the golden child among nutrients. But what happens if you eat more than you need?
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Protein has become the golden child among nutrients, particularly when compared to carbohydrates and fat. It's one of the few nutrients that people are continuously looking to boost intake, and because of this, some manufacturers have started adding extra protein to products like snack bars, crackers, and even ice cream.

Interest in getting adequate protein each day is a good thing since a lack of protein not only impacts lean body mass, but also stunts growth, impairs the immune system, and disrupts hormones and fluid balance. But what happens if you eat more than you need? Is there a downside? And can you really eat too much protein?

Keep reading to find the answer, along with how to determine your protein needs.

How much protein do you need?

To know what "too much" protein might look like, we've first got to determine protein needs, and one way to do this is to multiply your weight by the RDA reference amount (0.36g per lb of body weight). Based on this calculation, your protein needs may be much lower than you were expecting. This is because the RDA value is the amount that research suggests is "adequate" to maintain health, not necessarily the amount you need for optimal health. So what intake promotes health?

Research published over the last five years suggests that the optimal amount of protein for most people is closer to 1.2 to 1.6g/kg of body weight, an amount well above the RDA. This higher rate appears to be especially important for those who are active, as well as older adults for healthy aging. In fact, older adults were able to slow muscle loss associated with aging most effectively when they consumed protein amounts of 1.2g/kg of body weight. This is important since it's the loss of muscle and strength that leads to disability and fragility.

Protein Needs Based on Weight

Weight (kg)

Weight (lb)

150-lb person

220-lb person

RDA Reference Amount

0.8g/kg

0.36g/lb

54g

79g

Suggested Optimal Amounts

1.2 to 1.6g/kg

0.55 to 0.73g/lb

82 to 110g

121 to 161g

How's my protein intake right now?

Getting adequate protein from food each day isn't hard, and it doesn't necessarily require shakes, supplements, or protein-fortified foods. Meat, poultry, eggs, and seafood are often the first protein foods that come to mind, and they are good sources. But many other foods like legumes, nuts, whole grains, dairy products and even vegetables also contribute to your daily protein intake (see chart below). So when you factor in the amount of protein that you get from protein-dense foods, along with that contributed by the rest of your daily intake, most people come quite close to meeting needs.

Food

Protein

Roasted chicken breast, 3 oz

26g

Grilled steak, 3 oz

26g

Baked salmon, 3 oz

22g

Cooked lentils, 1 cup

18g

Black beans, 1 cup

14g

Nonfat Greek yogurt, 1/2 cup

11g

Whole-wheat bread, 2 slices

6-10g

Shredded cheese, 1/3 cup

9g

1% milk, 1 cup

9g

Cooked quinoa, 1 cup

8g

Peanut butter, 2 Tbsp

7g

Hard-boiled egg, 1 large

6g

Almonds, 1 oz

6g

Cooked brown rice, 1 cup

5g

Hummus, 1/4 cup

4g

Broccoli, 1 cup

2g

How much is too much?

Most people probably come close to meeting daily protein needs with food alone, so adding in extra protein (such as a protein shake for breakfast, a protein bar for snack, or a protein-focused meal out) can quickly push you well beyond even the optimal recommendations. So how much protein is too much?

While a maximum intake amount for protein has not been established, research suggests that most healthy adults can tolerate up to 2g/ kg of body weight (0.91g/ lb). However, very few people have a physiologic need for a protein intake this high. It's also important to note that exceeding this amount increases your risk for digestive issues and gout and may start to impair kidney function. Other factors to consider are the protein food sources you eat. Consuming higher-fat animal proteins increases intake of saturated fat and heart disease risk, while regular consumption of cured meats increases cancer risk. Also, excess protein can contribute to weight gain. The body can only use so much protein each day, and excess calories from protein can be stored as fat.

The best way to figure out where you stand with protein is to calculate your needs, but, remember, there's no exact amount. Most healthy people can start at the lower end of the optimal range (0.55g x weight in pounds) safely. Very active individuals may go a little higher. Then, keep track of what you eat for a few days and see how your protein intake compares.

Carolyn Williams, PhD, RD, is author to the new cookbook, Meals That Heal: 100 Everyday Anti-Inflammatory Recipes in 30 Minutes or Less, and a culinary nutrition expert known for ability to simplify food and nutrition information. She received a 2017 James Beard Journalism award, and her work is regularly featured in or on respective websites for Cooking Light, RealSimple, Parents, Health, EatingWell, AllRecipes, My Fitness Pal, eMeals, Rally Health, and the American Heart Association. You can follower on Instagram @realfoodreallife_rd or on carolynwilliamsrd.com.

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