Download the power of protein

THE POWER OF PROTEIN
Protein is part of every tissue, including your organs, muscles and skin, and plays a
major role in your body—from building, repairing and maintaining tissues, to making
important hormones and enzymes, to transporting nutrients. Since an adequate protein
intake is important throughout our lives, especially as we age, it’s smart to know about
the different types of protein, how much you need to consume and what foods provide a
good source of this powerful nutrient.
The Building Blocks of Protein
Amino acids are organic compounds that combine together in long chains to make
proteins. Considered the building blocks of protein, there are 20 different amino acids
needed by the body. Some amino acids are considered essential because the body
doesn’t make them and you need to get them from food. Other amino acids are made by
the body, so they’re considered nonessential.
Types of Protein
There are two types of protein: complete and incomplete. Complete proteins have the
right proportions of all the essential amino acids. They come from animal sources like
eggs, milk, meat, poultry and fish, as well as foods made from soy, such as tofu and
tempeh. Incomplete proteins are low in one or more essential amino acids. This includes
most plant proteins, such as beans, rice and nuts. You can combine some incomplete
proteins, including beans and rice, to get a protein that is considered complete.
How Much Do You Need?
The amount of protein you need each day varies based on your age, gender and activity
level. For healthy adults, the Food and Nutrition Board of the Institute of Medicine
recommends getting a minimum of 0.8 grams of protein for every kilogram of body
weight each day
1
. This is equal to about six grams of protein for every 20 pounds of body weight, which
would be 48 grams of protein for someone who weighs 160 pounds.
However, current research and expert opinion show that 0.8 grams of protein per
kilogram of body weight may not be enough as we age. The current recommendations
were made based on research in young adults and do not promote optimal health or
protect older adults from sarcopenic muscle loss (loss of muscle and function with
aging). Experts now estimate that older adults need 1.2 grams of protein per kilogram
of body weight or higher per day. Additionally, researchers recommend that adequate
protein intake with each meal is important to promote protein anabolism (or protein
building). These recommendations state that an intake of 25 to 30 grams of high-quality
protein per meal is necessary for optimal muscle protein synthesis, which is particularly
beneficial for older adults trying to maintain muscle mass.
Good Sources of Protein2
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Tuna (6 ounces, packed in water): 40 grams
Fish (6 ounces, cod or salmon): 40 grams
Chicken (4 ounces, skinless): 35 grams
Lean red meat (4 ounces): 35 grams
Lean pork (4 ounces): 35 grams
Tempeh (1 cup): 31 grams
Tofu (1/2 cup, raw, firm, prepared with calcium sulfate): 20 grams
Cottage cheese (1 cup, 1% or 2% fat): 28 grams
Black beans (1 cup, mature seeds, canned, low sodium): 14 grams
Edamame (1 cup, frozen, prepared): 17 grams
Yogurt (1 container, 170 grams, Greek, plain, nonfat): 17 grams
Milk (1 cup of 1%, 2% or fat-free): 8 grams
Almonds (1 ounce): 6 grams
1 Institutes of Medicine of the National Academies, Dietary Reference Intake for
Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein and Amino Acid.
September 5, 2002.
2 United States Department of Agriculture. National Nutrient Database for Standard
Reference. December 7, 2011. http://ndb.nal.usda.gov
Information provided is for general background purposes and is not intended as a substitute for medical diagnosis or treatment by
a trained professional. You should always consult your physician about any healthcare questions you may have, especially before
trying a new medication, diet, fitness program, or approach to healthcare issues.