Food, Hunger and the Human Diet
Food is any material eaten to supply the necessary nutrients for an organism to function normally. In the human body, food is generally of animal, plant or fungus origin, and has certain necessary nutrients, including proteins, carbohydrates, vitamins, or iron, which are needed to maintain the metabolism. The diet of humans varies widely according to the culture, time and geographic location in which they live. In the United States, diets largely consist of fruits, vegetables, whole grains, dairy products, meat, poultry and fish.
Nutrition is a science that studies how the human body uses foods to meet its nutritional requirements. The basic principles of nutrition state that all foods contain nutrients, but are delivered in differing proportions. Nutrient density is the key to nutrient intake. Nutrient density means the amount of nourishment required to raise the same body size in calories. A high-nutrient diet helps to build the body’s immune system, promotes health, and regulates metabolism to regulate energy and weight.
Various diseases can result from malnutrition, including chronic liver disease, arthritis, heart disease, high blood pressure, diabetes, infantile asthma, osteoporosis, kidney stones and cancer. The recommended daily allowance of vitamins is food-provided vitamins; a lack of vitamins can result in obesity, insulin resistance, depression, anxiety and poor concentration, fatigue, dizziness, headaches, constipation, diarrhea, gas and dizziness. Meats, dairy products, fish, beans, pulses, vegetables, bread, cereals, fruits, meats and fish are good sources of vitamins A, D, E and K. Meats, vegetables, bread and cereals are good sources of vitamin C, which is an important determinant of appetite.