Basics of Protein
Protein is an essential nutrient made from amino acid building blocks.
- There are 20 dietary amino acids.
- There are 9 of essential amino acids - you need them from your diet because your body cannot make them
- There are 11 non-essential amino acids. Your body can make them from the 9 essential amino acids.
Protein’s roles in the body include:
- Providing structure (e.g., in muscles and skin)
- Acting as enzymes (e.g., lipase to break down fat, amylase to break down starch, protease to break down protein)
- Transporting (e.g., hemoglobin carries oxygen and lipoproteins carry cholesterol
- Acting as hormones (e.g., insulin and glucagon)
- Supporting immune function (e.g., antibodies)
Protein and Weight Management
Protein has 4 calories per gram - the same as carbohydrates. Overconsumption of calories from protein is just like overconsuming calories from carbohydrates or fat. It can contribute to weight gain in excess.
Protein can also help with weight loss.
- Increases metabolism (burns more calories) with a higher thermic effect of food (TEF) than to that of carbohydrates of fat
- Helps stabilize blood sugar, which helps reduce cravings and sudden hunger
- Slows stomach emptying after a meal, helping you feel full longer
Protein Requirements
The Recommended Dietary Allowance (RDA) for protein is 0.8 grams of protein per kilogram of body weight per day.
Higher needs can be 1.2-1.5 grams of protein per kilogram of body weight. Some people with higher needs may include:
- People who are losing weight, especially rapidly or with GLP-1 medications
- Older adults
- Elite athletes, body builders, and other people training intensely
The Acceptable Macronutrient Distribution Range (AMDR) suggests that protein should make up 10-35% of your daily calories. It’s a range that supports long-term weight management, a balanced diet, and reduced chronic condition risk.
Ask your healthcare provider how much protein you need.
Nutritious Sources of Protein
Lean protein sources can include these.
- Skinless chicken breast and lean ground turkey
- Fish (like salmon and tuna) and shellfish (shrimp)
- Reduced-fat dairy (low-fat cottage cheese, plain nonfat yogurt)
- Eggs
- Plant-based options like lentils, beans, tofu, almonds, and peanuts
Less nutritious sources are often high in calories, fat, saturated fat, sodium, and nitrates. These include fatty and processed red meats like bacon, hot dogs, sausages, and fatty deli meats.
To make protein choices healthier, you can substitute options like deli meats with skinless chicken or tuna, ground beef with lean ground turkey, and fried chicken with roasted or grilled skinless chicken.
Plant-Based Protein
Plant-based proteins are often rich in fiber and low in saturated fat and cholesterol.
- Complete proteins like quinoa and soy (tofu, edamame) contain all nine essential amino acids.
- Incomplete proteins include legumes (beans, peanuts, and lentils), grains, nuts, and seeds
Complementary proteins are combinations of incomplete proteins that, when eaten together, provide all the essential amino acids. Examples include rice and beans, peanut butter on whole-grain bread, and veggie burgers made with beans and brown rice.
Protein Shakes and Supplements
Shakes, powders, and supplements can provide a protein boost or serve as a meal replacement. A drawback is they're not as filling per calorie and are considered liquid calories. Check for low sugar and adequate protein content when choosing a shake. Whole-food alternatives include hard-boiled eggs, cottage cheese, tuna pouches, or almonds.
