The term food refers to any material that is eaten to supply nutrition to an organism. Generally, food is of animal, plant or fungi origin, and comprises necessary nutrients, including proteins, carbohydrates, vitamins, or minerals. During digestion, food breaks down into smaller components called amino acids, which are the building blocks of proteins. Bacteria that break down plant foods (e.g., cabbage and lettuce) use enzymes to convert starches to simple sugars (glucose), and other bacteria break down animal proteins into simpler sugars (e.g., beef and chicken protein). Some plants can actually change the type of protein they produce by manipulating their growth conditions. Plants can even alter the structure of their root systems to improve the production and distribution of roots.
The human body requires a variety of different nutrients to survive. These nutrients are available in several food groups. Foods are categorized into food groups according to their chemical make-up and nutritional value. A number of nutrients that are found in large amounts in fruits and vegetables are considered to be “complete” nutrients by the medical community. These include vitamins A, C and E, potassium, iron, phosphorous and iodine.
There are several factors that affect nutrient absorption. Factors such as gender, race and ethnicity influence nutrient absorption rates, as do foods that are taken in combination. Different food items have different absorption rates; for example, fat, protein and carbohydrates all have varying absorption rates. However, the nutrient fatty acids are absorbed more slowly than carbohydrates and protein.
Fatty acids are important nutrients. The fat in meat and other animal sources, including butter, tallow, coconut oil and fats from plants such as palm nuts, are quickly digested and used by the body. The oil and tallow in tropical and subtropical oils, which are most common in sausages, are very low in saturated fats. Saturated fats are commonly known to raise cholesterol levels and cause heart disease.
Plants are a rich source of fiber, with beta-carotene being the main source of food Vitamin A. Milk products are also good sources of protein. Fruits and vegetables contain large amounts of antioxidants, which are important nutrients. A variety of fruits and vegetables is necessary to get enough vitamins and minerals. They are easily available and many are even frozen, dried or fresh. Most vegetable juice is available in powder form and mixed with water.
The health and nutritional value of food should be assessed on a daily basis. It is important to balance both the amount of food and the types of food that you eat. It is recommended that a healthy eating program include at least one major food group each day and consume foods from each food group throughout the day. Food needs will vary between individuals, depending on their needs for certain nutrients.