Food 4 Life - Find out what's in food

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Find out what's in food

 

This section outlines the key nutrients a person needs to maintain a healthy diet.  Most people should be able to get all the nutrients they need by eating a varied and balanced diet.   However, people at different stages of life may need different levels of various nutrients.  For example, a baby will have different requirements when compared to a teenager.  Our Ages & Stages section gives you more information on this. 

 

LEARNING OBJECTIVES

The key learning objectives for this section are that you will

Know the main nutrients required for a healthy diet

Identify sources of these nutrients in the diet

 

Protein

  • Protein is needed for growth and repair of body tissues and is also a source of energy.
  • The building blocks for proteins are amino acids, of which there are 20 commonly found in proteins from plant and animal sources.
  • Some amino acids can be made by the body. These are therefore said to be ‘non essential’ amino acids.  Others must be supplied in the diet. These are therefore said to be 'essential' amino acids.


Sources of Protein in the Diet

Foods of animal origin: Meat, fish, eggs, milk, cheese

Foods of vegetable origin: Peas, beans, lentils, nuts, cereals

Click here for our leaflet on protein

Click Here for more information on protein

 

Fats

  • Fats are essential for a healthy body, providing a source of energy and carrying vital nutrients.
  • Fats also play an important role in food manufacture and cooking making food taste good.  
  • There are different types of fatty acid, saturated and unsaturated.
  • Saturated fats are solid at room temperature whereas unsaturated fats are usually liquid at room temperature
  • A diet high in saturated fats may be associated with raised blood cholesterol levels.


Sources of Fat in the diet

 Saturated fats: Dairy products (e.g. butter, cheese), meat and meat products, eggs (yolk), palm oil, coconut oil, cakes, nuts


Unsaturated fats: Corn oil, sunflower oil, some margarines, oily fish, meats, soya oil

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Click Here for more information on Fats

 

Carbohydrates

  • Carbohydrates are our main source of energy
  • This group of nutrients includes sugars, starches and fibre
  • Sugar is a generic name for a range of substances of similar structure for example sucrose (table sugar), fructose (found in fruit), lactose (found in milk) and glucose
  • All these sugars provide 4kcal/g (17kj) of energy
  • There are two distinct categories of fibre – soluble fibre and insoluble fibre
  • Soluble fibre, as its name suggests is able to form a gel after consumption although it passes through the small intestine unabsorbed.
  • This type of fibre is found in fruit (eg apples), vegetables, pulses and some grains (especially oats)
  • Insoluble fibre is found in grains and fibrous vegetables.  It has a bulking effect on faeces and so decreases transit time through the gut.
  • Sugars give food its sweet taste

Sources of Carbohydrate in the diet

Fruits, cakes, biscuits, sweets, sugary drinks, potatoes, pasta, bread, cereals, rice, Wholegrain bread, wholegrain pasta, nuts, wholegrain rice, peas, beans, lentils.

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Vitamins

  • Vitamins are needed only in very small amounts.
  • Most vitamins cannot be made by the body and so must be provided by the diet. Vitamin D however, can be made by the action of sunlight on the skin
  • There are two groups of vitamins:

  • Fat soluble (vitamins A, D, E and K)

  • Water soluble (all the others, including vitamin C, and B vitamins)


Click here for more information on B Vitamins

Click Here for more information on Vitamins

 

Minerals

  • Minerals are required by the body for a variety of functions including
    • Formation of bones and teeth.
    • Essential constituents of body fluids and tissues.
    • Components of enzyme systems.
    • Nerve function.
  • Two minerals most often lacking in the diet are calcium and iron
    • Calcium: Calcium is the main mineral in bones and teeth.  An adequate calcium intake is vital to health, especially during periods of growth, pregnancy and lactation.

Dietary sources of calcium

Milk, cheese, yoghurt and canned fish containing soft bones e.g. canned salmon, green leafy vegetables, fortified bread.

  • Iron: Required for the formation of haemoglobin in red blood cells which transport oxygen around the body.  Iron deficiency causes anaemia, leading to fatigue and affecting work capacity, intellectual performance and behaviour.

Dietary sources of iron

Red meat and meat products are rich in available iron. Other meats, eggs, fish, bread, vegetables and fortified breakfast cereals also contain some iron.

  • Sodium:  Sodium regulates body fluid balance and is involved in nerve function.  Most raw foods contain very small amounts of sodium chloride (salt), and during processing, preparation, preservation and serving, additional salt is added.  Too much salt has been associated with hypertension (high blood pressure). 

Dietary sources of sodium

The main source of salt in the UK diet is from manufactured foods.  It may also be added to foods at the table.  Many food manufacturers have now reformulated their products to reduce the salt content.

  • Folate (folic acid): Involved in the formation of red blood cells.  Higher intake of folic acid or foods rich in folate, before conception and during the first 12 weeks of pregnancy reduce the incidence of neural defects in babies e.g. Spina Bifida. 

Dietary sources include wholemeal breads, fortified breakfast cereals, vegetables, oranges, milk, dairy foods, nuts and pulses.