Food is any substance ingested to provide nutrition to the organisms. In simple terms, food is a combination of nutrients provided for an organism by the environment. Generally, food is generally of animal, plant or even fungal origin, and comprises necessary nutrients, including proteins, carbohydrates, vitamins, or minerals, which an organism needs to grow and mature. The diet of humans includes all these nutrients in the form of food. However, food can also be used to supplement the diet. Animal products like meat, milk and eggs constitute the major part of human diets, whereas plant products, like vegetables, fruits and nuts constitute the major part of diets of animals.

A major portion of the diet is comprised of unprocessed food, which may consist of vegetables, fruits, grains and nuts. Plants contain carbohydrates, a basic building block of the body, while animal products, like meat, milk and eggs are rich in protein and provide the necessary nutrients. Unprocessed food also includes dietary supplements, which may consist of vitamins, minerals, herbs, essential oils, sugar substitutes, and various types of alcohols. Sugar is secreted by plants and is used by the organisms to process food into energy. Sugar is a universal need, but excessive intake of sugar may have detrimental effects on health.

A balanced diet, including appropriate proportion of fresh vegetables, fruits, grains, nuts, and other macro-nutrients, is important to maintain good health. An ideal balance of macronutrients should be considered, which consists of carbohydrate, protein, fat, potassium, sodium, calcium, iron, zinc, vitamins and minerals. Carbohydrate provides fuel for the body, while protein gives it the necessary energy to function. Potassium makes water content in the cells of the body, while sodium prevents constriction of the blood vessels. Iron is an important nutrient, which strengthens the bones and helps make the skin and hair strong and healthy.

A varied and healthy diet includes a balance of dietary fibre. Fruits and vegetables contain a wide range of fibre, which provides both soluble and insoluble nutrients. Fibre also helps regulate the levels of glucose in the blood, and so helps control insulin levels. Milk, eggs, and cheese are sources of dietary fibre. The best way to get a healthy balance of nutrients is to eat a well-balanced combination of foods, including plenty of fruits and vegetables, grains, nuts, seeds, fish, legumes, and dairy products.

The human body requires many other vitamins and minerals, as well as certain other food-borne toxins, in order to be healthy and fit. Vitamin B12, iron, magnesium, zinc, selenium, and thiamin are examples of food-borne diseases that you need to avoid. The best way to get these nutrients is to eat enough vitamin-rich food. Milk, eggs, fish, cereals, fruits, vegetables, and whole grain breads and cereals are good sources of vitamin B12.

Unprocessed foods may contain some allergens. If you suffer from allergies, you should check the ingredients of your diet to make sure there are no preservatives or colours that may cause an allergic reaction. A balanced diet, which includes all of these food types, can help reduce the risk of heart disease and other health problems. By choosing foods that are high in fibre, calcium, and other nutrients, you can keep your diet balanced and safe. You will feel better, as well as having a healthier, more nutritious life.