What is nutrition

Overview

Nutrition is the process by which your body takes in and uses food for energy, growth, and maintenance of body tissues. It encompasses everything from how your digestive system breaks down food into usable components to how your cells absorb and utilize these nutrients. Proper nutrition is foundational to living a healthy, active life and preventing chronic diseases.

The Six Essential Nutrients

Your body requires six types of nutrients to function optimally. Carbohydrates are your body's primary energy source, found in grains, fruits, and vegetables. Proteins build and repair muscles, skin, hair, and other tissues, coming from meat, eggs, legumes, and dairy. Fats provide energy and support hormone production, with healthy sources including nuts, avocados, and olive oil.

Vitamins are organic compounds that regulate metabolism and immune function, while minerals like calcium, iron, and zinc support bone health, oxygen transport, and enzyme function. Water comprises about 60% of body weight and regulates temperature, transports nutrients, and aids digestion.

Macronutrients vs. Micronutrients

Macronutrients are needed in large quantities and provide calories for energy: carbohydrates (4 calories per gram), proteins (4 calories per gram), and fats (9 calories per gram). Micronutrients—vitamins and minerals—are needed in smaller amounts but are critical for hundreds of metabolic processes. Without adequate micronutrients, even with sufficient calories, your health deteriorates.

Importance of Balanced Nutrition

Adequate nutrition supports immune function, helps fight infections, maintains healthy skin and hair, and supports bone density. It provides mental clarity, stable energy levels, and emotional well-being. Poor nutrition increases risk of obesity, heart disease, type 2 diabetes, certain cancers, and osteoporosis. Conversely, good nutrition can prevent or manage these conditions.

Individual Nutritional Needs

Nutritional requirements vary significantly between individuals based on age, sex, activity level, and health status. Children need more calories per pound of body weight for growth. Pregnant and nursing women have increased calorie and nutrient needs. Athletes require more protein and calories. Older adults need more vitamin D and B12 to maintain muscle mass and bone health.