Food is any substance consumed to provide energy for an organism. It is usually of plant or animal origin, and contains essential nutrients for growth and health. The study of food and nutrition is called food science.
People have a wide variety of eating habits and preferences, depending on culture and circumstance. The preparation and consumption of food is often a social activity, with a focus on sharing and caring. People may also choose particular foods to celebrate a special occasion or event, or to help ward off illness.
The human body uses carbohydrates, proteins and fats as energy sources. Food is ingested and absorbed into the organism’s cells to provide energy for its functions, and the remainder is excreted. The major source of calories for the human body is carbohydrates, followed by proteins and fats. Plants (including grains, fruits and vegetables) are a source of protein, while animals supply the body with fats and carbohydrates.
Humans are omnivores and can consume both plant and animal products. Before the development of agriculture, humans relied on hunting and gathering, horticulture, pastoralism and then on agriculture for their main sources of food. The ability to cultivate plants and raise domestic animals allowed humans to create a more stable food supply, providing them with enough energy to work, travel and survive.
In addition to supplying energy, foods can have a range of other properties that make them desirable or undesirable. For example, a food may be sweet, bitter or salty and it may contain aromas and flavors that affect the way the organism tastes it. In addition, some foods may be a source of disease-causing microorganisms or chemicals.
Eating a wide variety of healthy foods is important for good health. The Australian Guide to Healthy Eating groups the foods that we should eat into 5 major food groups:
Fats are an important part of our diets as they help keep us feeling full and supply our bodies with vitality. They also provide insulation and protect our internal organs. Fats can be found in many foods including meat, fish, nuts, seeds and vegetable oils. We should try to eat foods with lower levels of saturated and trans fats and higher levels of omega-3 fatty acids.
People who are interested in the preparation, cooking and culture of food are known as ‘foodies’. Some people have a professional interest in food, such as chefs and cooks, while others enjoy eating out at restaurants or making their own meals at home. The food industry has a large number of food related organizations and companies, such as the Food Marketing Institute, the Culinary Institute of America and the International Association of Culinary Professionals. There are also a number of government programs that help improve access to healthy foods for low-income communities, such as the USDA’s Food Stamp Program and the CDC’s State Physical Activity and Nutrition and Obesity programs. These programs help fund community-based initiatives such as grocery stores, farmers’ markets and bodegas that sell a variety of healthier foods.