Protein has enjoyed a recent surge in popularity thanks to low-carb diet fads and weight loss and fitness trends - but it's always been indispensible to your health. Protein can be found in a wide range of foods, like lean meats, eggs and legumes. While most aren't labeled "superfoods," they certainly act as such, helping to rebuild and restore the body, from building bone and muscle tissue to making sure your cells are in top condition. It doesn't matter if you're trying to bulk up or slim down – protein is a vital part of your daily diet.
What Is Protein?
Proteins are found in your skin, bones, muscles and all your organ tissue. It is also found in the hemoglobin that carries the oxygen in your blood, hormones, and the enzymes that play a part in the body's crucial chemical reactions. Though protein malnutrition is generally not a problem in developed nations like the United States, eating too little can result in growth failure, loss of muscle mass, a suppressed immune system, and weakness of the heart and respiratory systems. There are at least 10,000 proteins at work in your body. And they constantly need to be refueled.
Proteins: Complete and Incomplete
There are differences in the types of proteins you eat, some are "complete;" others are "incomplete," and you need them both. Proteins are made of 20 or so building blocks called amino acids. Complete proteins contain the 9 essential amino acids your body needs to build new proteins. Essential amino acids are ones the body can't produce on its own. Animal sources of protein tend to be complete. Other protein sources lack one or more of the essential amino acids; these are called incomplete proteins. These include fruits, vegetables, grains and nuts.
Because the body doesn't store amino acids, like it does with fat or carbohydrates, it needs a fresh supply of them every day to make new proteins. Complete and incomplete proteins play an equally important role in this process. The best way to get all the protein you need is to pick from wide and varied sources.
Eating the Right Amount
There is no hard and fast way to measure your required protein intake – but rather, there are a few: by percentage of calories, by weight and by age. This may be confusing, but the end numbers for all measures are not so much conflicting as they are inclusionary.
The Recommended Daily Allowance (RDA) change with age:
- Infants require about 10 grams a day.
- Teenage boys need up to 52 grams a day.
- Teenage girls need 46 grams a day.
- Adult men need about 56 grams a day.
- Adult women need about 46 grams a day.
- Pregnant or lactating women need about 71 grams a day.
Try Them All: Protein Sources
Consider this: a 6-oz. porterhouse steak will provide 38 grams of protein – and 44 grams of fat, 16 of them saturated (three-quarters of the recommended daily intake). An equal portion of salmon will provide 34 grams of protein and 18 grams of fat, 4 of them saturated. A cup of cooked lentils will give you 18 grams of protein and only 1 gram of fat. When choosing how you'll get your daily recommended dose of protein, try to incorporate as many plant-based sources first, then animal sources – and red meat last.
Lean cuts of beef and extra lean ground beef are good sources of complete proteins, but are also high in saturated fat. Limit your consumption of red meat and make it an only-sometimes option. Boneless and skinless chicken breasts and turkey cutlets are the leanest poultry choices. Meat portions should be about the size of a deck of cards. One chicken breast provides about 23 grams of protein.
Fish and Shellfish
Fish and shellfish offer high-quality protein. Fish like salmon, sardines, tuna, trout, herring and mackerel are "fatty fish," rich in omega-3s. Unfortunately, most fish and shell fish contain traces of mercury. The recommended allowance of fish per week is 12 ounces, or two fish meals a week.
Generally, larger fish that have lived longer accumulate higher levels of mercury; swordfish, shark, king mackerel are ones to avoid. Tuna steaks have more mercury than canned tuna; white albacore tuna has more mercury than light tuna. Tuna consumption should be limited to 6 ounces a week, or one of your 2 fish meals that week. One can of tuna (42 grams of protein) can provide almost an entire day's worth of protein for a woman (46 grams).
Eggs and Dairy
Eggs and egg whites are an excellent source of protein. They are also rich in vitamin B12, vitamin D, riboflavin and folate. Eggs are an energy-sustaining food that helps to stave of fatigue. Eggs should be eaten in moderation, as they contain dietary cholesterol, which can increase the risk of heart disease in people with elevated blood cholesterol levels. This cholesterol is found in the yolk; egg whites, on the other hand, are cholesterol free. Low-fat milk, yogurt and cheese are also abundant in protein. Cottage cheese is low in carbohydrates and provides 28 grams of protein, just be careful of its sodium levels. Yogurt provides about 14 grams of protein. One cup of milk has 8 grams of protein.
Dry beans, lentils, peas and soy/soy products (limited to 2 to 4 servings a week) are excellent and versatile options. Black, pinto, kidney, lima and garbanzo beans offer relatively equal amounts of protein; a serving of kidney beans provides about 15 grams. Beans can be added to soups, salads and used as the main ingredient for an entree. Think burritos, hummus, and yes, even veggie and black bean burgers count. Bonus: all are high in fiber.
Nuts and Seeds
Pine nuts, walnuts, almonds, peanuts, pecans and pistachios are more than snack foods: They are all rich in protein. Complement your meals with nuts; add them to salads, oatmeal and cereals, yogurt and main dishes. Nut are high in calories, but they are also nutrient dense. Nuts contain essential fatty acids. In addition, nuts mostly contain unsaturated fats, especially monounsaturated fat. This type of fat does not affect blood cholesterol levels. A 1/3 cup serving of nuts is equal to 1 ounce of meat. Pistachios are the heavyweights here – offering 9 grams of protein and 4.4 grams of fiber per serving. And don't forget about flaxseed. It truly is a superfood, loaded with fiber, omega-3s and high-quality protein. The body best absorbs nutrients from ground flax.
- Brain-boosting smoothie
- Spinach, walnut, citrus salad
- Buttermilk pecan fish filets
- Raspberry flaxseed shake
Whole Grains, Fruits and Vegetables
Certain quality grains like quinoa and millet are high in protein. Quinoa is a whole grain and a complete protein – a rare combination. A serving of quinoa can provide 24 grams of protein. Cutting back on white flours and highly processed carbohydrates and increasing your protein intake improves levels of blood triglycerides and HDL (the good cholesterol). These factors may help reduce chances of having a heart attack or stroke.
Fruits and vegetables offer very modest levels of protein. Dried apricots and prunes, cherries, avocados and leafy greens like spinach are good options.
- Creamy quinoa parfait
- Quinoa with roasted vegetables
- Linguine and quinoa meatballs
- Brazilian avocado shake
Protein and Weight Loss
High-protein diets are not about excluding all other food groups, but eating more protein has shown positive results when it comes to weight loss and diet maintenance.
Here's why: fish, chicken, beef, beans and other protein-rich foods don't travel as quickly from the stomach to the intestine. This basically means your stomach empties at a much slower rate – so you feel fuller longer, and as a result, eat less. Proteins don't cause a spike in blood sugar levels – and the subsequent crash. The body also has to use more energy to digest protein – you actually burn more calories in the process.