Essential Principles of Human Nutrition

Nutrition and dietetics are closely related fields, often overlapping in their scope. Nutrition serves as the scientific study of food components, their functions, and how they impact the human body, including potential adverse effects. Conversely, dietetics focuses on determining the nutritional needs of healthy and sick individuals and recommending appropriate diets. Typically, nutritionists work within the food industry, while dietitians primarily operate in healthcare settings.

Nutrients can be categorized as macronutrients and micronutrients. Macronutrients are required in large quantities to provide energy for the body. Energy is measured in kilocalories (kcal) or Joules. Specifically, 1 kcal equals 4.186 kJ.

Carbohydrates are the most abundant energy-providing macronutrient. They yield 4 kcal per gram and are chemical compounds made of carbon, hydrogen, and oxygen, including sugars like monosaccharides, disaccharides, and polysaccharides.

Proteins, composed of carbon, hydrogen, oxygen, and nitrogen, are essential for tissue repair and maintenance. They provide 4 kcal per gram. Proteins are made up of amino acids, which can be simple (monomers) or complex (polymers).

Fats, or lipids, supply approximately 9 kcal per gram and consist of triglycerides formed by three fatty acids attached to glycerol. Fats can be simple fatty acids or complex fats.

Dietary fiber, a type of carbohydrate, is not digested by the body but plays a vital role in keeping the digestive system healthy by facilitating food movement.

Water is crucial for many bodily functions, acting as a solvent, regulating temperature, aiding waste elimination, and ensuring proper blood flow.

Micronutrients, required in trace amounts, include minerals such as sodium, potassium, calcium, zinc, iron, iodine, and others. A balanced diet typically supplies these essential minerals naturally.