nutritie

Nutritie (nutrition) is the science that studies nutrients in foods and how the body uses them to sustain life, support growth, and maintain health. It encompasses the intake, digestion, absorption, metabolism, and excretion of nutrients, as well as the effects of dietary patterns on disease risk and well-being.

Nutrients are categorized as macronutrients and micronutrients. Macronutrients—carbohydrates, proteins, fats, and water—provide energy or structural components in larger amounts. Micronutrients, including vitamins and minerals, are required in smaller amounts but are essential for metabolic processes, immunity, and tissue maintenance. Dietary fiber, though not absorbed for energy, contributes to digestive health.

Energy balance is a core concept: energy intake from foods and beverages is measured in calories or kilojoules and is balanced against energy expenditure from basal metabolism, physical activity, and digestion. Imbalances can lead to undernutrition or overweight and obesity, increasing risk for noncommunicable diseases.

Nutrition science uses observational studies, clinical trials, and metabolic research to understand how nutrients affect health, how deficiencies arise, and how to optimize diets. Dietary guidelines and reference intakes help individuals plan diets that meet nutrient needs while considering cultural preferences and safety. Public health nutrition addresses malnutrition, food security, fortification, supplementation, and targeted programs.

Sustainability and nutrition intersect as food systems influence both health and environmental impact. Emphasis on diverse, minimally processed foods, adequate intake across life stages, and attention to individual circumstances underpins nutrition guidance.