Enough is Enough
In a balanced diet, protein matters. But how much (and what kind of) protein do you need?
Judging by the jumbo-sized containers of protein shakes and powders lining the shelves at your grocery or vitamin shop and the magazine ads for protein supplements featuring men and women with impossibly tight six-pack abs, America is in a nationwide protein deficit. But that’s far from the truth.
“The typical American diet is sufficient in protein,” says Shannon Weston, MPH, RD, LD, a registered dietician with UT Health Services at The University of Texas Health Science Center at Houston (UTHealth). “People often think they need to increase protein intake because they lift weights. Often, they don’t need to because they most likely already consume enough protein to reach their goals. Just eating more protein doesn’t mean you’re going to build more muscle. You’ve got to do the work in the gym.”
It seems that everyone — from your constantly-on-a-diet aunt to your fitness-obsessed neighbor — is trying to get their hands on as much protein as they can. The truth about the value of protein in the diet and how it benefits our health frequently gets obscured by fancy marketing campaigns and misinformation.
Protein is certainly one of the most important nutrients in a balanced diet, but unless you’re in year-round training for the Ironman races every weekend, the “more is better” approach does not apply to protein consumption.
What is protein anyway?
“Protein is part of every cell, tissue and organ of the body and is constantly being broken down and replaced,” Weston says. “The body uses protein from the diet to build new cells, maintain tissues and synthesize proteins to make it possible to perform basic bodily functions.”
Weston continues that the proteins we consume are digested into amino acids — the “building blocks” of protein — which are later used to replace these proteins in the body. About twenty different amino acids form together to make all types of protein, and they are separated into two groups: essential and non-essential amino acids.
According to the Centers for Disease Control and Prevention (CDC), essential amino acids are those that our bodies cannot make, so we must acquire them through our diet, while non-essential ones are produced by the body. Additionally, protein sources are defined as complete or incomplete. A complete source is one that provides all of the essential amino acids and includes animal-based sources such as meat, milk, eggs, poultry and fish. Incomplete sources are low in one or more of the essential amino acids.
It has become commonplace to identify carbohydrates as “good” or “bad,” but categorizing the types of protein in such a simplistic manner doesn’t adequately describe the key differences in the varieties of protein.
“I always encourage people to eat lean sources of animal protein such as fish, turkey or skinless chicken,” Weston says. “Look for beef, veal and pork of lamb with the word ‘round,’ ‘loin’ or ‘lean’ on the package because it contains less fat, particularly saturated fat, which can have a negative effect on cholesterol levels and heart health.
“The cooking method matters as well,” she says. “Foods that are grilled, boiled, baked or steamed are healthier options than foods that are fried. Vegetarian options for protein, such as beans, lentils, low-fat dairy, nuts, seeds and tofu are heart-healthy options.”
To ensure that you are selecting healthier protein sources, the CDC recommends such tips as substituting pinto or black beans for meat in chili or tacos; choosing low-fat or fat-free milk; choosing low-fat or fat-free cheese and opting for egg whites or pasteurized egg white products.
Getting enough in your diet
While we accept that protein is a good thing, it only stands to reason that too much of a good thing can have a detrimental impact on your health. Weston says the optimal breakdown of the key nutrients of the average diet is 45 to 50 percent from carbohydrates, 25 to 30 percent from protein and 20 to 25 percent from fat.
“The recommended daily allowance (RDA) of protein is 46 grams for women 19 to 70 years old and 56 grams for men in the same age bracket,” Weston says. “Of course, it depends on the individual and how active they are, so it’s not a cookie cutter amount. For the general population, where many of us live fairly sedentary lifestyles and work out a couple of times a week, the RDA is about right. But if you’re a pro athlete or running marathons, your protein needs increase. I see people [at UT Health Services] who need more because they are very active.”
But before you start thinking that if 56 grams per day is good, then 156 must be great, know this: too much protein in your diet can trigger some nasty consequences, including possible kidney damage and weight gain.
According to research by the Palo Alto Veteran’s Administration Medical Center, eating a quantity of protein that is more than 30 percent of your daily caloric intake can be dangerous, especially if it is not accompanied by an increase in physical activity. Such an increase can lead to the development of additional fat and the buildup of organic compounds called ketones, which the kidneys have to work overtime to get rid of, resulting in, among other things, dehydration.
And those protein supplements that seem to be everywhere? Weston advises using caution in their use.
“Supplements are not regulated by the government, so some of them might not be a healthy choice. Some are loaded with sugar, extra calories and fat, so it’s important to read the labels,” she says.
For athletes and those living a more active lifestyle, Weston says eating enough protein before a workout is a good idea. However, it is more important to consume enough carbohydrates so the body has energy (glucose) to burn without resorting to breaking down the protein and muscle stores necessary to fuel the workout.
Weston says protein helps to preserve lean muscle, so people who do not get enough protein in their diet can begin to experience “muscle wasting,” a condition where the body begins burning muscle for fuel instead of fat and calories.
Consuming enough protein will help preserve lean muscle mass. This increases metabolism because muscle burns more calories than fat, so not getting enough protein can slow metabolism. “It is rare that I see a patient who is not getting enough protein. Almost all of us are at least getting the RDA. It only becomes an issue if someone has mild renal disease and needs to be on a low protein diet,” Weston says.
No meat, no problem?
It has long been believed that meat is the best source of protein and that strict vegetarians run the risk of starving their bodies of protein, but Weston says that does not have to be the case.
“It’s certainly possible to get the required amount of protein from a well-planned diet that doesn’t include meat,” she says. “Vegetarians can get enough of the protein they need through foods with healthy protein sources like whole grains, tofu, dairy and Greek yogurt, nuts, seeds, beans and lentils.”
Protein’s role in weight loss
Getting the proper amount of protein per day should be a central part of any weight reduction plan.
“Protein has the highest satiety rate of any of the macro nutrients, so it keeps you fuller for longer,” Weston explains. “It also helps maintain lean muscle mass, so when you’re trying to lose weight and you’re dealing with a calorie deficit, you need to get sufficient protein in your diet. That way you burn fat, not muscle which, ultimately, fuels your metabolism and helps burn more calories.”