Nutrition is the process by which organisms obtain and utilize food for their growth, maintenance, and overall health. Proper nutrition is essential for energy, cellular repair, and overall functioning.

Nutrition Overview

Types of Nutrients

Nutrients can be broadly categorized into macronutrients and micronutrients:

  1. Macronutrients:
  • Carbohydrates: Provide energy. Sources include grains, fruits, vegetables, and legumes.
  • Proteins: Build and repair tissues. Sources include meat, dairy, legumes, and nuts.
  • Fats: Provide long-term energy, support cell growth, protect organs, and keep the body warm. Sources include oils, butter, avocados, and nuts.
  1. Micronutrients:
  • Vitamins: Organic compounds required in small amounts. They are crucial for various bodily functions.
  • Minerals: Inorganic elements that support processes like bone formation, heart function, and fluid balance.

Scientific Basis

Nutrients are essential for the body to function correctly. They support growth, metabolism, and overall health. The scientific basis for nutrition is derived from biochemistry, physiology, and molecular biology.

Chemical Sources

  • Carbohydrates: Starches, sugars, and fibers found in fruits, grains, vegetables, and milk products.
  • Proteins: Composed of amino acids found in animal products, legumes, and nuts.
  • Fats: Saturated, unsaturated, and trans fats from oils, butter, fish, and processed foods.
  • Vitamins: Organic molecules found in fruits, vegetables, meat, and dairy.
  • Minerals: Elements like calcium, potassium, and iron found in various foods.

Medicinal Uses

  • Vitamin C: Boosts the immune system, treats scurvy.
  • Vitamin D: Prevents rickets, supports bone health.
  • Iron: Treats anemia.
  • Calcium: Prevents osteoporosis.
  • Omega-3 fatty acids: Supports heart health.

Normal Amounts Used in the Body

  • Carbohydrates: 45-65% of daily calories.
  • Proteins: 10-35% of daily calories.
  • Fats: 20-35% of daily calories.
  • Vitamins and Minerals: Varies by type (e.g., Vitamin C: 75-90 mg/day; Calcium: 1000 mg/day).


  • Carbohydrates: Provide energy.
  • Proteins: Essential for growth and repair.
  • Fats: Provide energy, support cell function.
  • Vitamins: Prevent deficiencies and chronic diseases.
  • Minerals: Support various bodily functions (e.g., bone health, fluid balance).


  • Excess Carbohydrates: Can lead to obesity and diabetes.
  • Excess Proteins: May strain kidneys.
  • Excess Fats: Increase risk of heart disease.
  • Vitamin and Mineral Overdose: Can cause toxicity (e.g., hypervitaminosis A, iron poisoning).

Deficiencies or Excesses

  • Carbohydrate Deficiency: Leads to fatigue, poor mental function.
  • Protein Deficiency: Causes muscle wasting, weakened immune system.
  • Fat Deficiency: Affects hormone production, brain function.
  • Vitamin Deficiencies: Cause specific diseases (e.g., Vitamin C deficiency leads to scurvy).
  • Mineral Deficiencies: Lead to health issues (e.g., calcium deficiency causes osteoporosis).


Proper nutrition is vital for maintaining health, preventing disease, and ensuring the body functions optimally. A balanced diet with the right proportions of macronutrients and micronutrients is essential for well-being.