a healthy diet

nutrients are substances/chemicals that are needed by the body to keep it in good health

carbohydrate

    a major source of energy in the diet

    it is composed of carbon and hydrogen

    it is also referred to as saccharides which means ‘sugars’

    there are three classifications:

        monosaccharides - easy for the body to relate with

            glucose (food)

            frutose (fruits)

            galactose (breastmilk)

        disaccharides (two monosaccharides)

            maltose (glucose + glucose)

            lactose (glucose + galactose)

            sucrose (glucose + frutose)

        polysaccharides (multiple monosaccharides)

            starch

            cellulose

            glycogen

    when anything is processed in the body, it breaks down to glucose

    when there is excess glucose, the pancreas produces insulin

    the insulin changes the glucose to glycogen and that is stored either in the liver or     under the skin

    types of carbohydrates include: starches, fibres and sugars

lipids - fats and oils

    they are made of large numbers of carbon and hydrogen with oxygen atoms

    there are two types

        solid fats

            solid at room temperature

            produced by animals

            e.g lard, milk fat, chicken fat etc.

        liquid fats

            liquid at room temperature

            produced by plants

            e.g sunflower oil

    processed in the body to make fatty acids and glycerol

    this is stored under the skin in the adipose tissue

    it helps regulate body temperature, formation of new cell membrane and gives larger     amounts of energy than carbohydrates

    1g lipids → 9k calories

    calories are the unit of energy for energy

    if a person does not eat, their body gets it’s nutrients from the stored ones

proteins

    they are made of carbon, hydrogen, oxygen and nitrogen

    the atoms join together to make amino acids which join together to make proteins

    some contain sulphur and phosphorous

    amino acids → peptides → protein

    proteins are needed for building structures in cells and to form tissues and organs

    this is a macronutrient along with lipids and carbohydrates

vitamins

    they are needed in small amounts because they help with body chemistry

    there are different types

        A, B1, B2, B6, B12, C, D, E, K, etc.

    vitamin A helps with eyes to improve sight

    vitamin B helps increase energy levels, brain function and cell metabolism

    vitamin C deficiency causes scurvy

    vitamin D helps to make strong bones and teeth

minerals

    the body needs 20 different minerals to keep healthy

        minerals like calcium that are needed in large quantities are called major elements

        others like zinc, that are needed in smaller quantities are called trace elements

    examples include:

        calcium, magnesium, iron, potassium, zinc, chlorine, iodine, phosphorous, sodium,         copper, selenium