Protein is a major nutrient the body uses to grow, maintain, and repair itself. It is especially important during childhood and the teen years, when muscles, bones, skin, blood, and organs are developing. Protein also helps make enzymes, hormones, and immune system parts that keep the body working well.
Getting enough protein supports healthy growth, but it works best as part of a balanced diet with carbohydrates, fats, vitamins, minerals, and water.
When you eat protein, digestion breaks it into smaller building blocks called amino acids. The body then reuses those amino acids to build body proteins, such as muscle fibers, skin proteins, and proteins involved in healing. Good protein sources include beans, lentils, eggs, fish, poultry, lean meats, dairy foods, soy foods, nuts, and seeds.
Students can support growth by eating protein at meals and snacks, choosing a variety of foods, and pairing protein with regular sleep, physical activity, and healthy hydration.
Key Facts
- Protein is made of amino acids, which the body uses to build and repair tissues.
- Complete proteins contain all 9 essential amino acids in useful amounts.
- Protein provides about 4 Calories per gram.
- A common general estimate for daily protein need is about 0.8 g protein per kg body mass for many adults, while growing teens may need more depending on age, body size, and activity.
- Protein helps form muscles, skin, hair, nails, enzymes, hormones, antibodies, and many cell structures.
- Healthy protein sources include beans, lentils, eggs, dairy, fish, poultry, lean meat, tofu, tempeh, nuts, and seeds.
Vocabulary
- Protein
- A nutrient made of amino acids that the body uses to build, repair, and maintain tissues.
- Amino acid
- A small molecule that links with others to form proteins in the body.
- Essential amino acid
- An amino acid the body cannot make in enough amount, so it must come from food.
- Tissue repair
- The process of replacing or fixing damaged body cells after normal wear, exercise, or injury.
- Balanced diet
- A pattern of eating that includes a variety of foods to provide enough nutrients and energy for health.
Common Mistakes to Avoid
- Thinking protein only builds muscles is wrong because protein also helps build and repair skin, bones, blood, organs, enzymes, hormones, and immune system parts.
- Eating only one protein food every day is a mistake because different foods provide different amino acids, vitamins, minerals, and healthy fats.
- Assuming more protein always means faster growth is wrong because healthy growth also needs enough total energy, sleep, exercise, water, and other nutrients.
- Ignoring plant protein sources is a mistake because beans, lentils, tofu, nuts, seeds, and whole grains can provide useful protein and other important nutrients.
Practice Questions
- 1 A student has a mass of 50 kg. Using 0.8 g protein per kg body mass, estimate the student's daily protein need in grams.
- 2 A meal contains 2 eggs with 6 g protein each and a cup of yogurt with 12 g protein. How many grams of protein are in the meal?
- 3 A student wants to support healthy growth but does not eat meat. Explain how the student could still get enough protein and name at least three protein-rich foods they could choose.