Food is a substance eaten to provide nutrients required for human survival. It may be of plant or animal origin and contains essential substances such as carbohydrates, fats, proteins, vitamins, and minerals. The consumption of food satisfies physiological needs, provides pleasure and social bonds, and contributes to cultural traditions and identities.
A healthy diet includes a variety of foods from each of the five major food groups. Foods should be low in fat, salt and added sugar, and contain adequate amounts of protein and fiber. It is also important to consume enough fluids, especially water.
Many people who eat unhealthy diets suffer from obesity, heart disease, high blood pressure, diabetes and other health conditions. The cost of healthy eating can be prohibitive for some individuals, but there are ways to make healthier choices on a budget. For example, buying local produce in season is often cheaper than purchasing it from a supermarket. It is also possible to save money by preparing meals at home rather than dining out, making homemade soups and stews, and packing healthy snacks for work or school.
The scientific study of food is called food science, and it involves a broad range of topics such as the chemical properties of foods, the nutritional value of different foods, and how to preserve foods. It is an evolving field because of rapid socioeconomic changes in the developed world, which have increased demand for ready-to-eat foods that require less preparation time at home and are more nutritious than traditionally prepared meals. This has created new challenges for the food industry, which must develop more convenient and nutritious products while reducing food waste.
Several factors influence the nutrient content of foods, including their genetic makeup and growing environment. Food processing also has an impact, as it can alter the nutrient content of foods by adding or removing nutrients, such as fats, sugars and salt.
A healthy, balanced diet is key to good health. It is recommended to eat foods from all of the food groups, with the exception of very sweet and fatty foods, in order to get the best variety of vitamins and minerals.
For example, protein-rich foods like meat, fish and dairy are great sources of iron, while vegetables are an excellent source of vitamin C. Tryptophan, an amino acid found in many protein-rich foods, is also thought to help improve mood by influencing the production of serotonin in the brain.
When dining out, choose smaller portion sizes, such as a starter instead of an entree or splitting a dish with a friend. Avoid fried foods, as they tend to be high in calories and fat. Also, be aware that salad dressings and sauces may add extra kilojoules to your meal. Try to use salad dressings and sauces that are low in fat, or make your own using a light vinaigrette. Finally, try to include foods that contain probiotics, which can help support a healthy gut.