Food is any substance consumed by an organism to provide nutritional support. It is usually of plant or animal origin and contains essential nutrients such as carbohydrates, fats, proteins, vitamins and minerals. Different organisms require different foods to satisfy their metabolic needs and dietary requirements. Food may be prepared and eaten in a variety of ways, for example, by boiling, roasting, baking, stewing, or frying. People also preserve and store food by canning, freezing, drying, smoking, salting or pickling.
The most important component of a healthy diet is whole foods. People should avoid processed foods that are high in sodium (salt), sugar and unhealthy fats. Instead, choose nutrient-dense whole foods like lean meats, eggs, fish, beans, nuts and fruits. Try to cook meals from scratch with few added ingredients. The healthiest cooking techniques are baking, steaming and sauteing in a small amount of water or oil. Avoid frying foods because this process can create carcinogens such as heterocyclic amines and polycyclic aromatic hydrocarbons, which are linked to cancer.
Humans are omnivores, and our diets have evolved over time to reflect this. Early humans were hunter-gatherers, and their diets varied depending on what was available in their environment. Later, with the advent of agriculture and animal husbandry, humans settled in one place, which changed their food habits. Humans now eat a wide range of foods, including cereal grains, fruits and vegetables, legumes, meats, dairy, and oils.
A person’s diet should contain a mix of whole foods to provide the body with all the nutrients it requires for good health. Most foods can be classified as either whole foods or processed foods. Unprocessed foods are rich in vitamins, minerals and dietary fiber and are low in saturated fat, trans fat and sodium. Processed foods are rich in salt, sugar and unhealthy fats and are often high in calories. Using the Nutrition Facts label and ingredients list can help to identify the types of food that are best for a healthy diet.
Staple foods, such as whole grains, fruits and vegetables, are rich in vitamin C, folic acid, iron and dietary fibre and should be part of every meal. Try to choose low-sugar, lower-fat foods when possible, such as fresh berries or sliced tomatoes with reduced fat mozzarella cheese.
The most common foods that are rich in potassium are bananas and avocados. Aim to eat one of these fruits each week. Other potassium-rich foods include sweet potatoes, dried apricots and peaches, and canned tuna and salmon.