Nutrition and Fitness Planning

Grade 8 · Health · Study Guide

Explore how balanced nutrition and regular physical activity work together to support a healthy lifestyle.

Good nutrition and regular physical activity are the two pillars of a healthy lifestyle. What you eat provides the energy and nutrients your body needs to grow, think, and perform — while exercise strengthens your heart, muscles, and bones.

Nutrients are divided into macronutrients (carbohydrates, proteins, and fats) and micronutrients (vitamins and minerals). Carbohydrates are the body's primary energy source, proteins build and repair tissue, and fats support brain function and hormone production. The USDA's MyPlate model recommends filling half your plate with fruits and vegetables, one quarter with grains (preferably whole grains), and one quarter with lean proteins, plus a serving of dairy or a calcium-rich alternative.

Physical activity guidelines for teens recommend at least 60 minutes of moderate-to-vigorous activity every day. This includes aerobic exercise (like running or swimming), muscle-strengthening activities (like push-ups or resistance bands), and bone-strengthening activities (like jumping or basketball). Rest and sleep are equally important — most teens need 8–10 hours of sleep per night for optimal recovery and performance.

When planning a fitness routine, setting SMART goals (Specific, Measurable, Achievable, Relevant, Time-bound) helps maintain consistency and track progress. Hydration is also critical — teens should drink about 8–10 cups of water daily, more during exercise.

Key terms

Macronutrients
Nutrients needed in large amounts: carbohydrates, proteins, and fats, which provide energy and building materials.
MyPlate
USDA's nutrition guide showing the recommended proportions of food groups on a plate: fruits, vegetables, grains, protein, and dairy.
Aerobic exercise
Continuous rhythmic activity that increases heart rate and breathing, improving cardiovascular fitness (e.g., running, swimming).
SMART goals
A goal-setting framework: Specific, Measurable, Achievable, Relevant, and Time-bound.
Caloric balance
The relationship between calories consumed through food and calories burned through activity; balance supports a healthy weight.
Micronutrients
Vitamins and minerals needed in small amounts that support functions like immune response, bone health, and energy metabolism.

Flashcards

Carbohydrates
The body's main fuel source; found in grains, fruits, vegetables, and legumes.
Protein
Builds and repairs muscles and tissues; found in meat, eggs, beans, and nuts.
Healthy fats
Unsaturated fats found in avocados, nuts, and fish that support brain function and heart health.
Whole grains
Grains that retain the bran, germ, and endosperm; higher in fiber and nutrients than refined grains.
Resting heart rate
The number of heartbeats per minute when the body is at rest; a lower rate generally indicates better cardiovascular fitness.
Muscle-strengthening activities
Exercises like push-ups, squats, and resistance training that build muscle strength and endurance.
Hydration
Maintaining adequate fluid intake; teens need 8–10 cups of water daily, more during physical activity.
BMI (Body Mass Index)
A measure using height and weight to estimate body fat; used as a general health screening tool.

Questions

  1. How many minutes of moderate-to-vigorous physical activity do teens need each day?

    1. 30 minutes
    2. 45 minutes
    3. 60 minutes
    4. 90 minutes
    Show answer

    Answer: 60 minutes

    The CDC and WHO recommend at least 60 minutes of moderate-to-vigorous physical activity daily for children and teens.

  2. Fats should be completely eliminated from a healthy diet.

    Show answer

    Answer: False

    Healthy fats are essential for brain function, hormone production, and absorbing fat-soluble vitamins like A, D, E, and K.

  3. Which macronutrient is the body's primary energy source?

    1. Protein
    2. Fat
    3. Carbohydrates
    4. Vitamins
    Show answer

    Answer: Carbohydrates

    Carbohydrates are broken down into glucose, which is the body's preferred and most efficient energy source.

  4. The USDA nutrition guide that uses a divided plate to show food group proportions is called _____.

    Show answer

    Answer: myplate

    MyPlate is the USDA's current dietary guide, replacing the old Food Pyramid, showing proportions of food groups on a divided plate.

  5. Sleep is an important component of a fitness and recovery plan for teens.

    Show answer

    Answer: True

    Sleep (8–10 hours for teens) is when muscles repair, growth hormone is released, and the body recovers from physical activity.

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