On a population basis, consumption of some or all of these foods varies between nothing (in vegetarian societies) to negligible amounts (in low-income societies) to 20 per cent or more of total energy (notably in some richer developed countries). Meat and poultry intake is low in most African countries, India and other low-income Asian countries, typically contributing less than 3 per cent total energy. Worldwide, meat and poultry contribute, on average, 9 per cent total energy. The highest intakes are in Denmark, where meat and poultry contribute 24 per cent total energy, and in Australia, New Zealand, Argentina and Bermuda, where these foods provide around 20 per cent of total energy.

Consumption of fish and seafood also varies widely in different parts of the world.As a general rule, meat consumption increases with economic development. For example, between 1980 and 1987, meat intake in Japan rose from around 18 g/day to 71 g/day per person. Between the 1960s and the 1990s, poultry consumption has risen in almost every country, with a worldwide average increase of 50 per cent.

Egg consumption has been reported to be around six eggs per person per week in the USA. Egg consumption has increased by 100-200 per cent in Asia over the past 25 years but is still lower in most Asian countries than in the USA.

Meat, poultry, fish and eggs are good sources of protein and various vitamins and minerals. The fat content of meat and poultry varies widely; meat from domesticated animals typically contains substantial amounts of fat, particularly saturated fats. Fatty fish are good sources of essential polyunsaturated fats. Eggs are a source of protein. Non-domesticated animals are a significant source of meat among some populations in extreme northern climates, in North Africa, in Islamic countries and the Eastern Mediterranean and in some rural areas of the USA. There are important differences, particularly in fatty acid content and composition, between meats from domesticated animals and 'wild' meats. Offal is also a form of meat, but there is little epidemiological evidence specific to this group of meats.

Meat, poultry and fish contain around 20 per cent protein, by weight. The fat content of meat, poultry and fish ranges from a low of less than 4 per cent fat for lean poultry and some types of fish, to 30-40 per cent fat by weight for fatty meat from domesticated farmed animals fed on cereals (grains) and pulses (legumes). Wild meat is typically low in fat.Saturated fatty acids make up around 40-50 per cent of the total fatty acids in meat. In the USA, these meats have been reported to contribute around one-third of saturated fat intake.

Poultry contains a somewhat lower proportion of saturated fatty acids (35 per cent) and a higher proportion of polyunsaturated fatty acids (15-30 per cent as compared with 10 per cent). Fat from fish contains even less of saturated fatty acids (20-25 per cent) and oily fish are a rich source of omega-3 fatty acids. Intensively reared poultry and farmed fish contain more fat than free-ranging or wild equivalents. Meat and poultry are rich sources of the B vitamins B6 and B12, and of readily absorbable iron, zinc, selenium and fatty acids. Fish contains relatively lower levels of B vitamins and iron and zinc than meat and poultry, but oily fish are a rich source of retinol and vitamin D; fish are a good source of calcium when the bones are eaten. Eggs are moderate sources of protein and fat. The yolks of eggs are high in dietary cholesterol.

Herbs
Herbs, spices and condiments are part of diets worldwide. Many of them have known pharmacological and therapeutic properties relevant to human health, and most contain potentially potent bioactive compounds. Practically all diets include seasonings, flavourings, savours and sauces made from herbs, spices and other edible substances that have aromatic, pungent or other flavours, aromas and colours.Various herbs contain high levels of carotenoids and vitamin C.

Herbs and spices also contain very variable amounts of a number of bioactive compounds, whose relevance to human health is not yet fully understood. General knowledge of the therapeutic qualities of many herbs and some spices suggests that further human studies may yield evidence of a relationship with cancer. The fact that herbs, spices and condiments, by their nature, normally make up only a very small part by volume and weight of any diet is not in itself a reason to dismiss them as insignificant.

Consumption of herbs, spices and condiments varies greatly in different parts of the world. Consumption probably varies inversely with consumption of salt, which here is not classified as a condiment. Many traditional cuisines are typified by the use of herbs, spices and condiments, singly or in combination, mixed into food in cooking or at the table.

Herbs, spices, and condiments may have specific functions. For example, they may make dull, distasteful or decaying food palatable. They may make otherwise ordinary food delicious. They may be preservatives. Many herbs and spices are believed to have medicinal or tonic value and, in some societies, are mixed into meals in various combinations and quantities to prevent or treat common diseases. Many pharmaceuticals are derived from herbs and other plants, and traditional therapies typically make use of herbs as medicines.