1. Let's start at the beginning. WTF is protein actually? @vonabiszett / Via instagram.com Protein is a broad term for molecular chains of amino acids, the organic compounds that the body needs for a variety of different functions. The foods we eat contain a variety of different proteins, all with different amounts and kinds of amino acids. During digestion these proteins are broken down into their component amino acids. "The body absorbs these amino acids, then reconfigures them into different proteins to meet the body's needs," registered dietitian Brian St. Pierre, director of performance nutrition at Precision Nutrition, tells BuzzFeed Health. Some proteins play a role in hormone signaling, others in muscle and tissue growth, still others in digestion, and so on. "Protein is critically important for the immune system to work properly, for bone health, for body composition, for almost everything," says St. Pierre. 2. When dietitians talk about proteins they generally mean any food (or food product) whose dominant macronutrient is protein (as opposed to fat or carbohydrates). Getty Images Take a can of tuna fish. One serving has 13 grams of protein and 0 grams of carbs and 0 grams of fat. So, tuna fish is considered a protein. Same deal with turkey (a serving has 0 grams of carbs, 0 grams of fat, and 10 grams of protein), tofu (2 grams of carbs, 3.5 grams of fat, 10 grams of protein), and roast beef (<1 gram of carbs, 3 grams of fat, 15 grams of protein). A large egg has less than 1grams of carbs, 4.75 grams of fat, and about 6 grams of protein. So, even though the egg and the beef provide some fat, they're considered proteins.On the other hand, protein-containing foods might not be considered proteins per se when their dominant macronutrient is fat (like peanut butter, which has about 16 grams of fat and 8 grams of protein per serving) or carbs (like black beans, which have about 18 grams of carbs and 6 grams of protein per serving). You want to get protein from a variety of protein-containing foods (more on that shortly), so it helps to get a little familiar with what other macronutrients come along for the ride as you think about your protein intake. 3. Protein is kinda special because of its ability to keep you full for a long time. @cheatdayeats / Via instagram.com Protein is, by far, the most satiety-promoting macronutrient, says St. Pierre, which means it helps you feel full after you're done eating. In fact, when people eat enough protein, they tend to eat fewer calories overall, which makes it important for anyone interested in weight management. So whether you're interested in losing weight, not being hangry, or both, having protein at meals and as snacks will help. Here are some great high-protein snacks. 4. Most Americans are probably getting enough protein — just maybe not from the healthiest sources. Getty Images For most people who more or less eat a standard American diet where meat and cheese figure pretty prominently, getting adequate protein isn't usually an issue, says St. Pierre. But because fast and processed foods are a significant part of the diet, we're also taking in a lot of sugar, salt, and additives with all of that important protein. And if you're eating a lot of, say, cheeseburgers, you might also be taking in a good amount saturated fat, which probably isn't as detrimental to health as we used to think, but from a heart-health perspective, it shouldn't be the main type of fat you eat. So, when figuring out your protein needs, it's not just about how much you're getting but also about what kind you're consuming. 5. Vegans might have to put a little more thought into their protein intake, especially if they're super active. @isachandra / Via instagram.com Because vegetarians can eat Greek yogurt, eggs, and cheese, it's not as tough for them to meet their protein needs as it would be for a vegan. If you're 100% plant-based you might need to be extra mindful that you're eating enough protein. Lots of whole plant-based foods (like beans, lentils, and nut butters) have decent amounts of protein, as do more processed foods like tofu and seitan. But because you'd have to eat large amounts of whole plant-based foods to get adequate protein, some vegans (especially athletes) use protein powder or supplements to ensure they're getting what they need, says St. Pierre. 6. As you might already know, the more active you are, the more protein you tend to need. @xtinebyrne / Via instagram.com You probably know that weightlifters love protein because it helps repair muscles and facilitate their growth after any kind of resistance training. But cardio enthusiasts should get involved with protein, too. Long cardio workouts temporarily suppress the immune system, says St. Pierre. Because protein plays an important role in immune system support, it can help runners, cyclists, and endurance athletes in general recover and stay healthy.Protein's role in maintaining bone health, repairing muscles, facilitating muscle tissue growth, and supporting the immune system make it crucial for basically anyone, whether you're pursuing general health and fitness, weight loss or management, or body composition goals like getting swole or decreasing body fat. 7. And if you're a regular exerciser, have some protein after you work out. @mx_ej / Via instagram.com Unless you exercise hard frequently or are a competitive athlete, you probably don't need to obsess over the number of minutes that elapse between your workout ending and when you consume a super precise amount of protein. But because protein does play such an important role in exercise recovery and muscle repair, physician assistant Bobby Hold of NYU Langone Medical Center recommends having some protein (up to about 20 grams, which would be about four slices of deli turkey, a few eggs, or a scoop of protein powder) within about 30 minutes of doing a resistance-training workout. "This will prevent your body from using its own muscle tissue for energy and help encourage muscle synthesis," Hold says.Hold says that having the protein long after that 30-minute window will still support muscle repair and growth, just not as effectively as when your body is most ready to make use of that abundance of protein. 8. Aim to get your protein from a variety of sources, including plant-based sources. Bhofack2 / Getty Images The best protein intake strategy is to get a good mix of all different sources, says St. Pierre. "Don't try to hyper-focus on one particular source," he says. Eating a variety of foods means you're getting a variety of nutrients, says Hold. Beans will provide fiber, red meat will provide iron, peanut butter and almonds provide vitamin E, while fatty fish, tofu, and walnuts provide essential fatty acids. And, of course, making sure you're not getting all your protein from foods that are also sources of saturated fat (cheese, milk, red meat) means that you're also keeping an eye on your heart health. 9. Just because adequate protein is good, it doesn't mean a ton of it is way better. @elena_sette / Via instagram.com It might seem that if 20 grams of protein after a workout will help gains, 40 grams will help your gains twice as much! But St. Pierre says that once you're meeting your body's protein needs, there comes a point when consuming more of it doesn't really do much for you. And there's actually a reason to chill on the protein intake as long as you're getting enough. St. Pierre says that usually when people are super focused on protein, they end up not getting enough of the other stuff they need, like carbs and fat, and all the nutrients in those foods. 10. You can do a bit of math if you want some hard numbers on what your protein intake should look like. @sweetfin / Via instagram.com For most people who aren't that active, the usual equation for how much protein you should eat daily is 0.8 grams of protein per kilogram of bodyweight. So, a 150-pound person would convert their weight to kilograms and multiply that number by 0.8. It would look like this: 0.8 X 68 = 54.4 grams of protein per day. The more active you are, the more protein you'll need. St. Pierre says that active people should aim for 1.4 to 2.2 grams of protein for every kilogram of bodyweight. You can also use this handy USDA calculator that does all the math for you.Here are some common foods and how much protein they have per serving: 1 large egg: 6.28 grams 1 slice cheddar cheese: 6.4 grams1 can of tuna: 40.73 grams1/4 package of tofu: 7 grams 1/2 cup of black beans: 6 grams2 slices of roasted turkey breast: 10 grams 2 tablespoons peanut butter: 7.7 grams1 container plain Greek yogurt: 18 grams1/2 cup of lentils: 8 grams 11. But you can also basically eyeball it. Precision Nutrition / Via precisionnutrition.com If you don't want to count, St. Pierre recommends a more visual way of keeping track of your protein intake. Use the palm of your hand to estimate one serving of protein and count the number of "palms" you eat daily. St. Pierre recommends that active women eat four to six palms of protein per day and active men six to eight per day. Because your hand size tends to be consistent with the size of the rest of your body, this should be a reliable way to get the protein you need. You can get more info on eyeballing your portions the Precision Nutrition way here. 12. Don't be afraid to snag a protein bar when you're in a pinch. @mrscbasler / Via instagram.com Even though St. Pierre suggests not relying on packaged foods like protein bars to make up a significant part of your protein intake, there will be times when a protein bar is your healthiest option and best chance at staying fuller for longer. If you're in a pinch and all that's available is fast food or packaged snacks, a protein bar is likely to be your best choice. Here are some guidelines for choosing healthier packaged snacks (including bars) and you can also check out this list for bars that have protein and aren't terrible for you. 13. When it comes to protein powders, choose one that's high in protein and low in crap. @adriennenadinehess / Via instagram.com If you're super active, super busy, and/or vegan, you might be in the market for a protein powder. No matter where the protein comes from (whey, pea protein, etc.), make sure that it contains 20 to 25 grams of protein per scoop and less than 5 grams of carbs, says St. Pierre. And the fewer the ingredients the better because that means it has less additives. 14. And if you're too busy to cope with balanced meals, turn a protein shake into an actual meal by adding a bunch of delicious stuff. @vitamix / Via instagram.com A protein shake can become a super shake, aka a whole foods meal, if you throw in some delicious stuff to make it heartier, says St. Pierre. Instead of just protein powder and water or milk, a super shake also contains fruit, vegetables, a healthy fat like nut butter or avocado, and a topping like cinnamon, coconut, or yogurt. Basically you're getting a lot of nutrition, including protein, in a portable, convenient way. Again, if the choice is between grabbing a fast food breakfast or snack or whipping up a super shake with protein powder, the latter will provide more nutrition and satiety.Get some ideas to mix-and-match super shakes here.