Protein is essential to health. The word comes from the Greek protos, meaning "first," and its origin reflects the supremacy of protein in human nutrition. You need it to grow flesh on your bones, make hair, blood, connective tissue, antibodies, enzymes, and more. It's common for athletes and bodybuilders to consume large amounts of extra protein to build up their physiques. But the message the rest of us often get is that we are consuming too much protein each day.
The Recommended Dietary Allowance (RDA) for protein is a modest 0.8 grams of protein per kilogram of body weight.The RDA is the amount of a nutrient you need to meet your basic nutritional needs. In a sense, this is the minimum amount you need to avoid getting sick, not the specific amount you should eat each day.
To determine your daily protein intake, you can multiply your weight by 0.36 pounds or use this online protein calculator. For a 50-year-old woman who weighs 140 pounds and is sedentary (not exercising), that equates to 53 grams of protein per day.
But using the RDA to determine how much protein you need each day actually causes a lot of confusion. Nancy Rodriguez, a registered dietitian and professor of nutritional sciences at the University of Connecticut in Storrs, says: "There are misconceptions about the RDA not only among the public, but in our profession as well." "People usually think we all eat too much protein."
Rodriguez was one of more than 40 nutritionists who gathered in Washington, D.C., for the Protein Summit to discuss research on protein and human health. The summit was organized and sponsored by the beef, egg, and other animal-based food industry groups, but it also produced a set of scientific reports that were independently published in a special supplement to the June issue of the American Journal of Clinical Nutrition (AJCN).
Protein: The more the merrier?
For a relatively active adult, daily protein intake to meet the RDA requirement provides only 10% of his or her total daily calories. In contrast, the average American consumes 16% of his or her daily calories in the form of protein, which comes from both plant and animal sources.
The Protein Summit on AJCN reports that 16.6 percent is definitely not an excess. In fact, the report suggests that Americans may be consuming too little protein, not too much. These researchers believe that the potential benefits of a higher daily protein intake include maintaining muscle strength in the face of aging and maintaining a lean, fat-burning physique. Some of the studies described in the Summit report suggest that protein is more effectively consumed at regular meals and snacks throughout the day than when many Americans wolf it down at dinner.
Based on all of the research presented at the summit, Rodriguez estimated that consuming more than twice the RDA for protein "is a safe and appropriate target range." This amounts to about 15 to 25% of your total daily caloric intake, though it may be higher or lower depending on your age, gender, and level of exercise.
Over the past few years, however, the public health message has shifted from the desired percentages of protein, fat, and carbohydrates. For example, current dietary guidelines for Americans emphasize the importance of eating healthy protein-rich foods rather than focusing on a specific daily protein content.
What should you do?
Research on how much protein to eat to stay healthy is ongoing and far from certain. For example, the value of a high-protein diet for weight loss or cardiovascular health remains controversial.
Before you start increasing your daily protein intake, there are a few important things to consider. First, don't read "get more protein" as "eat more meat." Beef, poultry, and pork (as well as milk, cheese, and eggs) certainly provide high-quality protein, but so do many plant-based foods, including whole grains, beans, and other legumes, nuts, and vegetables. The table below provides some of the healthier sources of protein.
It is also important to consider the "mix" of protein—the fats, carbohydrates, vitamins, minerals, and other nutrients that always come together with protein. Aim for a protein source that is low in saturated fat and processed carbohydrates and rich in multiple nutrients.
One more thing: If you add protein, dietary calculations require you to eat less of something else to keep your daily calorie intake steady. The changes you make can affect your nutrition, for better or worse. For example, eating more protein instead of low-quality refined carbohydrates, such as white bread and candy, is a healthy choice, although the healthiness of the choice also depends on the total amount of protein.
Kathy McManus, registered dietitian and director of nutrition at Harvard-affiliated Brigham and Women's Hospital, says: "If you're not eating a lot of fish, but you want to increase your fish intake, yes, that may improve your overall nutrition and, in turn, your health." "I think the data argues against a significant increase in red meat and processed meat to get protein."
If your main concern is weight loss, it makes sense to try a high-protein diet, but don't expect it to be a cure-all. Patients come to me all the time and ask me if consuming more protein will help them lose weight. I tell them that the verdict is still out. Some studies support it, some don't. "
Good sources of proteinFood Protein (Grams)
3 ounces of cod or trout, 21 grams.
19 grams cooked turkey or chicken, 3 oz.
6 ounces Greek yogurt, plain17 grams.
12 cup shredded white cheese14 grams
8 g cooked beans, half a cup
8 g milk, 1 cup
8 gram cooked Italian pasta
1/4 cup nuts (mixed)7 grams
6 g from one egg