• A diet is the combination of foods typically eaten by a specific group of people or other organisms. Human diets are determined by nutritional needs, the types of food available in a particular region, and cultural beliefs.

    Nutritional Needs

    A balanced diet is one that provides all of the nutrients needed for good health and proper growth.

    No single food can provide all the nutrients people require. As a result, people combine many different kinds of foods in many ways to meet their nutritional needs.

    The nutrients we need include carbohydrates, fats, proteins, minerals, and vitamins. Carbohydrates mostly come from plants, and include starches and sugars. Fats come from both plants and animals, and include vegetable oils such as corn oil and olive oil, and animal fats from meat, fish, dairy products, and eggs.

    Proteins are found in nearly all foods in varying amounts. Animal products, legumes, whole grains, and nuts are particularly rich in proteins.

    Vitamins and minerals are also found in most foods in varying amounts. Different foods are rich in different vitamins and minerals. Orange vegetables such as carrots, sweet potatoes, and pumpkins are all high in vitamin A. Citrus fruits contain lots of vitamin C. Meat, legumes, and spinach provide iron. Dairy products are high in calcium.

    Most animals have the same dietary requirements as people: vitamins and minerals, proteins, carbohydrates, and fats.

    Herbivores are organisms that consume only plants. They digest the tough fibers in plants and do not need meat for nutrition. Herbivores are often called primary consumers because they are the first (primary) eaters of autotrophs, or organisms that produce their own food.

    Some herbivores, such as pandas and koalas, have such specialized diets that they need to eat all day. Pandas mostly eat bamboo, while koalas mostly eat leaves from eucalyptus trees. Both bamboo and eucalyptus have very low nutritional value. Pandas and koalas must eat tons of the plants to fulfill their dietary requirements for nutrition.

    Animals that eat meat are secondary consumers. Carnivores, which mostly eat meat, and omnivores, which eat both plants and meats, are secondary consumers. The diets of secondary consumers are often more varied than primary consumers. Because meat usually has more energy and calories than plants, secondary consumers often eat less often than primary consumers. While koalas and pandas eat for hours every day, a lion may only eat once a week.

    Regional Foods

    Before the development of modern transportation and food storage, people’s diets depended on the plants and animals that thrived in the areas where they lived. Even today, people who live by the ocean tend to eat a lot of seafood. People in tropical climates have access to a variety of tropical fruits such as coconuts, bananas, or breadfruit. People in temperate lands can grow wheat easily, and people in warm, wet climates often grow rice in waterlogged soils.

    Most traditional diets rely on a food staple—usually a grain or tuber (potato or root vegetable)—and a variety of other foods that are eaten in lesser amounts. For example, rice is prominent in Japanese cuisine, along with fish, noodles, soy products such as miso and tofu, vegetables, and tea.

    In Mexico, corn is a staple food, often in the form of corn tortillas. The traditional Mexican diet also includes tomatoes, squash, sweet potatoes, and chocolate. Mexican foods are often flavored with chili peppers such as jalapenos, poblanos, and serranos.  

    Diet and Culture

    Culture plays a major role in dietary choices. Our social values influence what we eat, how we prepare food, and when we consume it.

    For example, culture dictates which edible plants and animals are considered food. In the United States, most people consider dogs and horses to be pets, not food. However, horsemeat is a common dish in Central Asian countries like Kazakhstan, and dog meat can sometimes be found in restaurants in some Southeast Asian countries, including Vietnam. Most westerners also object to the thought of eating insects, but they are considered delicacies in other parts of the world. People native to Australia and the island of New Guinea enjoy grubs. In Bali, Indonesia, dragonflies boiled in coconut milk are considered a delicacy. People in Ghana enjoy fried or roasted termites.

    Religion often plays a role in diet. For example, Hindus will not eat beef because cattle are considered sacred. Jewish and Muslim beliefs forbid eating pork. Many Hindus, Jains, and Buddhists avoid eating animals altogether.

    A diet that does not include meat, fish, or poultry is called a vegetarian diet. Religion is just one reason people choose to become vegetarians. Other reasons include personal health, concern for animal welfare, or concern about the environment.

    Vegans are vegetarians who avoid all animal products, including eggs, milk, cheese, and honey.

    In addition to affecting what people eat, culture also shapes how foods are prepared and served. For instance, people in India typically use a complex combination of spices to season their dishes. Japanese cuisine, on the other hand, embraces simplicity to showcase the freshness of the ingredients.

    Traditional diets developed around the foods that were available in a particular location and the traditions of each particular cultural group. Today, however, we have the ability to import foods from all over the world, and modern communications make it easy for us to learn about and try many different cuisines. No one is surprised today to find Greek food in Cincinnati, Ohio; fast-food burgers in Tokyo, Japan; or a Pakistani restaurant in London, England. 

    In developed countries, many people have abandoned traditional diets in favor of highly processed foods. The high levels of sugar, salt, and refined grains in these foods, however, have led to increased levels of diabetes and heart disease. Obesity is a common problem in countries with an abundance of these inexpensive, high-calorie foods.

    As a result, many people in developed countries are adopting new, healthier diets. For example, some people are choosing to buy only seasonal, locally grown foods. Others are seeking out organically grown foods. Many people seek out more humanely produced animal products such as free-range chicken or grass-fed beef. A lot of foods today also contain additives that increase their nutritional value, such as orange juice containing calcium or eggs fortified with omega-3 fatty acids.

    Many people are also rediscovering healthier, traditional diets. For example, Native American communities have a high risk of diabetes. Recently, some Native American communities in California, such as the Pomo, have encouraged the use of acorns and acorn flour. Acorns were a staple food in the Pomo diet for centuries. A diet with acorns, squash, and other traditional ingredients is full of nutrients and does not contribute to a risk of heart disease or diabetes.

    This dish of antipasto is not part of a vegetarian or vegan diet!

    Raw Deal
    People who follow a raw foods diet wont eat any foods that are cooked. Raw food has many more nutrients than cooked food.

    Many who follow a raw food diet are vegans or vegetarians, but some eat uncooked animal products as well.

    Those who follow this diet must be careful when choosing foods because certain plants can be poisonous if they are not cooked. Raw animal products can also pose a risk of food poisoning.

    Ancient Pyramids
    Traditional diets are built around food pyramids. Healthy physical activity forms the widest part of the pyramid, the base. The foods that make up traditional diet pyramids are grown locally or have a history of preparation in the area.

    There are four major types of traditional diet pyramids: Mediterranean diet, Asian diet, Latino diet, and vegetarian diet.

  • Term Part of Speech Definition Encyclopedic Entry
    abundance Noun

    large amount.

    acorn Noun

    nut of an oak tree.

    autotroph Noun

    organism that can produce its own food and nutrients from chemicals in the atmosphere, usually through photosynthesis or chemosynthesis.

    Encyclopedic Entry: autotroph
    bamboo Noun

    type of huge, woody grass.

    beef Noun

    flesh of a cow used for food.

    calcium Noun

    chemical element with the symbol Ca.

    calorie Noun

    unit of energy from food, equal to the amount of heat required to raise the temperature of one kilogram of water by one degree Celsius.

    carbohydrate Noun

    type of sugar that is an important nutrient for most organisms.

    carnivore Noun

    organism that eats meat.

    Encyclopedic Entry: carnivore
    cattle Noun

    cows and oxen.

    chili pepper Noun

    plant native to the Americas whose fruit and seeds are cultivated for food and spice.

    citrus Noun

    type of fruit tree, including lemon and orange.

    climate Noun

    all weather conditions for a given location over a period of time.

    Encyclopedic Entry: climate
    coconut milk Noun

    clear liquid contained in the center of a coconut.

    communication Noun

    sharing of information and ideas.

    complex Adjective


    consume Verb

    to use up.

    cuisine Noun

    a style of cooking.

    cultural belief Noun

    faith or custom created and supported by a community's traditional behavior.

    culture Noun

    learned behavior of people, including their languages, belief systems, social structures, institutions, and material goods.

    dairy Adjective

    having to do with the production of milk, cream, butter, or cheese.

    delicacy Noun

    food or dish notable for its rarity or cost.

    developed country Noun

    a nation that has high levels of economic activity, health care, and education.

    diabetes Noun

    disease where the body is unable to produce or regulate certain types of carbohydrates.

    diet Noun

    foods eaten by a specific group of people or other organisms.

    Encyclopedic Entry: diet
    digest Verb

    to convert food into nutrients that can be absorbed.

    edible Adjective

    able to be eaten and digested.

    embrace Verb

    to support enthusiastically.

    eucalyptus Noun

    tree native to Oceania.

    fat Noun

    material found in organisms that is colorless and odorless and may be solid or liquid at room temperature.

    fiber Noun

    long, thin, threadlike material produced by plants that aids digestive motion when consumed.

    food Noun

    material, usually of plant or animal origin, that living organisms use to obtain nutrients.

    Encyclopedic Entry: food
    food staple Noun

    food that is eaten frequently, either fresh or stored for use all year.

    Encyclopedic Entry: food staple
    forbid Verb

    to disallow or prohibit.

    fortify Verb

    to strengthen.

    free-range Adjective

    having to do with livestock or poultry that have been allowed to graze instead of being fed on a feed lot.

    fruit Noun

    edible part of a plant that grows from a flower.

    grain Noun

    harvested seed of such grasses as wheat, oats, and rice.

    Encyclopedic Entry: grain
    grass-fed beef Noun

    meat from cattle that have been raised on grass pastures, not corn feed lots.

    grub Noun

    larval, or worm-like, stage of insect development.

    heart disease Noun

    illness affecting the heart and circulatory system.

    herbivore Noun

    organism that eats mainly plants and other producers.

    Encyclopedic Entry: herbivore
    Hindu Noun

    religion of the Indian subcontinent with many different sub-types, most based around the idea of "daily morality."

    humane Adjective

    kind or gentle.

    import Verb

    to bring in a good or service from another area for trade.

    inexpensive Adjective

    not costing a lot of money.

    iron Noun

    chemical element with the symbol Fe.

    Jain Noun

    follower of the religion of Jainism, which supports nonviolence toward all living things.

    jalapeno Noun

    medium-sized, hot chili pepper that is usually green.

    Jewish Adjective

    having to do with the religion or culture of people tracing their ancestry to the ancient Middle East and the spiritual leaders Abraham, Isaac, and Jacob.

    legume Noun

    type of plant with a pod that splits, with seeds in the middle, such as peanuts.

    meat Noun

    animal flesh eaten as food.

    mineral Noun

    nutrient needed to help cells, organs, and tissues to function.

    miso Noun

    thick paste made from soybeans, salt, and a grain (usually rice).

    Muslim Adjective

    having to do with Islam, the religion based on the words and philosophy of the prophet Mohammed.

    Native American Noun

    person whose ancestors were native inhabitants of North or South America. Native American usually does not include Eskimo or Hawaiian people.

    nutrient Noun

    substance an organism needs for energy, growth, and life.

    Encyclopedic Entry: nutrient
    nutrition Noun

    process by which living organisms obtain food or nutrients, and use it for growth.

    obesity Noun

    medical condition where excess body fat increases risk for disease and death.

    omega-3 fatty acid Noun

    chemical, usually found in plant oil, that has been linked to improved blood circulation and reduced risk for heart disease.

    omnivore Noun

    organism that eats a variety of organisms, including plants, animals, and fungi.

    Encyclopedic Entry: omnivore
    organic Adjective

    produced according to standards using limited amounts of chemical additives.

    organism Noun

    living or once-living thing.

    poblano Noun

    large, mild chili pepper that is usually dark green.

    Pomo Noun

    people and culture native to Northern California.

    pork Noun

    meat from pigs.

    poultry Noun

    domesticated birds, such as chickens.

    primary consumer Noun

    organism that eats plants or other autotrophs.

    processed food Noun

    food that has been chemically or physically altered from its natural form, for taste, preservation, or storage.

    prominent Adjective

    important or standing out.

    protein Noun

    one of many complex compounds, made of chains of amino acids, that make up the majority of all cellular structures and are necessary for biological processes.

    religion Noun

    a system of spiritual or supernatural belief.

    sacred Adjective

    greatly respected aspect or material of a religion.

    seafood Noun

    fish and shellfish consumed by humans.

    secondary consumer Noun

    organism that eats meat.

    serrano Noun

    small, hot chili pepper that is usually green or red.

    soil Noun

    top layer of the Earth's surface where plants can grow.

    soy Noun

    beans, or fruit, of the soybean plant, native to Asia.

    specific Adjective

    exact or precise.

    spice Noun

    tasty and aromatic plant substances used in cooking.

    starch Noun

    carbohydrate found in many vegetables and cereals.

    sugar Noun

    type of chemical compound that is sweet-tasting and in some form essential to life.

    temperate Adjective


    tofu Noun

    thick, soft substance of varying consistency made from soybeans.

    tortilla Noun

    flat, round bread made from corn or flour.

    transportation Noun

    movement of people or goods from one place to another.

    tropical Adjective

    existing in the tropics, the latitudes between the Tropic of Cancer in the north and the Tropic of Capricorn in the south.

    tuber Noun

    thick part of an underground stem of a plant, such as a potato.

    vegan Noun

    person who does not eat meat or any animal product.

    vegetable oil Noun

    liquid fat extracted from a plant.

    vegetarian Noun

    person who does not eat meat.

    vitamin Noun

    chemical substance that is necessary for health.

    vitamin A Noun

    chemical substance necessary for healthy eyesight and skin. Also called retinol.

    vitamin C Noun

    chemical substance important for health. Also called ascorbic acid.

    waterlogged Adjective

    flooded or overflowing with water.

    welfare Noun

    health or well-being.

    wheat Noun

    most widely grown cereal in the world.