The Components of the human diet

By Demetra and Raphael

The main components:Food Energy

Fats/lipids

Sodium

Carbohydrates

Fibres

Proteins

Vitamins

Minerals

They are also called Nutrients

A Nutrient It is a chemical substance found in food that is used by the body

Essential Nutriments cannot be formed by the body:

Water

Vitamins

Proteins (polymers of amino acids)

Some unsaturated fatty acids -> Proteins are polymers of amino acids

Some amino acids

Some Minerals

A Nutrient It is a chemical substance found in food that is used by the body

Non-essential Nutrients can be replaced or formed by the body:

Carbohydrates / Sugars

Other minerals

Saturated fatty acids / fats

Other amino acids

Fatty AcidsBasic:

Efficient Energy StorersTogether with the Coenzyme A (CoA):

Efficient Energy StorersWe also know that the Plasma membrane of

cells is made of a phospholipid bilayer. There is another use of fatty acids: They are used for cholesterol, building the hydrophobic part of the layer, giving it stability.

They are also used as lipid hormones such as steroids

Omega 3 FatsThe Omega number tells us the position of the

double bond of the unsaturated fatty acid:

Omega 3:

A large intake can prevent the blood from clotting, preventing heart attacks and strokes

Cis and Trans:

Trans fats can be dangeous since the body thinks they are saturated acids, but then it doesnt know what do do with them

Fatty Acid Sources Possible effects

Omega-3Fish, Nuts, Vegetable oils

Reduces blood pressure /clotting and tryglicerides

Trans FatsPartially hyrdogenated oils, marrgarines, deep fried foods

Reduces helpful Cholesterol, increases blood pressure

Saturated Fats

Meat, Seafood, Diary products, Coconut oil

Can lead atheroscleriosis and to strokes and heart attacks

Vitamins !!Vitamins are organic compounds (made of C, O,

H)

Vitamin C:

Vitamin Function Sources

Vitamin A Eye function, vision, hair, skin

Dairy, Meat, Fish

Vitamin B Nervous system, control, digestion, coenzymes (enzyme assistants)

Dairy, meat, spinach, Brocoli, Salads,

Vitamin C Immune system, healing, anti.oxidants

Fruits (especially citrus)

Vitamin D Calcium absorption: Bones and teeth

Seaweeds, seafood, fish, dairy

The RDIIt is the recommended daily intake of a

nutrient and is set by government health bodies and the world health organisation

A lack of vitamin C in your diet can lead to pale skin, a slow scurvy healing process and sunken eyes

Vitamin C The RDI for Vitamin C is 40-60 ml per day, this is

explained below:

Vitamin CExcessive doses of Vit C are usually just

excreted by the body,

However, An excessive intake of vitamin C can „spoil“ the body so it starts getting used to high levels of a nutrient, the body adapts by making the absorbing of the nutriment less efficient

Vitamin DIt is produced by the skin

Paler skin produces more vitamin d than darker skin. Therefore, darker skinned people need more vit d in their diet, especially in colder countries

Paler skin has a higher risk of developing skin cancer, so in very hot countries, these poeple need to eat extra vit do to prevent this risk.

MineralsMinerals are ionic elemants that are positively or

negatively charged

MineralsIodine is used by the thyroid gland to produce

hormones which are responsible for monitoring metabolism and body temperature

Calcium is essential for cell physiology, where movement of the calcium ion Ca2+ into and out of the cytoplasm functions as a signal for many cellular processes. As a major material used in mineralization of bones and shells, calcium is the most abundant metal by mass in many animals.

Dietary fibreFibre itself is not absorbed into the blood and it is

not digested

However, many high-fibre foods (including vegetables) are packed with other useful nutrients

It mainly works for the stomach, but it also helps regulating blood sugar and can reduce blood cholesterol by blocking uptake of lipids in the diet

Phenylketonuria (PKU)PKU is a genetic disease caused by a mutated gene on

chromosome 12.

Normally, phenylalanine is converted into tyrosine by an enzyme, allowing normal brain development.

People with PKU cannot convert phenylalanine. When the body tries to get rid of the excess, toxins are produced which affect brain development. It can lead to severe mental problems and learning difficulties.

Roughly 1/18000 babies is born with the recessive gene.

Children with PKU should follow a special diet low in protein to avoid excessive phenylalanine.