Nutrition

Week 13

Tutor: Linda York

Linda York

Learning Outcomes• Identify rich sources of carbohydrates, proteins,

fats, fat soluble vitamins A and D, water soluble vitamin C and mineral ions (6)

• Identify the need for a balanced diet (5)• Investigate the comparison of the energy

content of nutrients (8)• Analyse and interpret the information on a food

label (17)• Investigate the effects of reducing or increasing

the various components in the diet (12)

Linda York

Learning Outcomes• Identify the benefits of fibre in the diet (11)• Explain the consequences of calcium and iron

deficiency (9) • Explain the consequences of excess salt and sugar

(10)• Investigate the issues involved in adding chemicals to

food and water (16)

• Investigate quantitative tests for energy content (18)• Evaluate quantitative and qualitative data on food

analysis (19)

Linda York

Food we eat

Take a few minutes to write down what you had to eat and drink today.

Linda York

Rich sources of carbohydrates, proteins, fats, fat soluble vitamins A and D, water soluble vitamin C and

mineral ions.

• Carbohydrates - • Proteins -• Fats -• Vitamins A and D -• Vitamin C -• Mineral Ions -

Consider the foods within these groups – you have5 minutes.

Linda York

The Energy Content of Nutrients

• Carbohydrate 1 gram = 16 kJ• Protein 1 gram = 17 kJ• Fat 1 gram = 37 kJ

What do you think the following energy figures are?

Carbohydrate 1 gram = ? kJProtein 1 gram = ? kJFat 1 gram = ? kJ

Linda York

Food Labelling

Linda York

Food labelling

Linda York

Diet Problems

• Having too much or too little of any type of food in your diet can cause you health problems.

• Body Mass Index indicates if you are under or overweight.

• The body mass index (BMI) is used as a guide to help decide whether someone is underweight, normal, overweight or obese. It is calculated from their height and weight.

Linda York

BMI

How to calculate BMI

body mass (in kg)

(height)² (in metres²)

Body Mass Index Weight Description

below 18.5 - underweight18.5 – 24.9 - normal25 – 29.9 - overweight30 – 40 - moderately obeseabove 40 - severely obese

Linda York

BMI

BMI isn’t always reliable. Athletes have lots of

muscle, which weighs more than fat, so they can come out with a high BMI even though they are not overweight.

Linda York

BMI

To calculate your BMI, you divide your weight (in kilograms) by the square of your height (in metres). So, for example, if you weigh 70 kg and are 1.75 metres tall, your BMI is 70 ÷ (1.75 x 1.75), which equals 22.9.

Linda York

BMI

The answer is 25.94What is the BMI of a person weighing 85 kg and with a height

of 1.81 m?

Linda York

Too much food

Obesity is defined as being 20% (or more) over your recommended body weight.

Too much sugary or fatty food and too little exercise are the main causes of obesity.

People can also be obese due to an underactive thyroid gland, but this problem isn’t common.

Obesity can increase the risk of diabetes, arthritis, high blood pressure, coronary heart disease (CHD) and even some forms of cancer e.g. breast cancer.

Linda York

Too little food

This can be a lack of one or more specific types of food, or not enough of any sort (starvation).

Young children, the elderly and women tend to suffer most and the effects vary depending on what foods are missing from the diet.

Common problems include slow growth (in children), fatigue and poor resistance to infection.

Linda York

Too little Protein

Eating too little protein can cause a condition called kwashiorkor.

A common symptom is a swollen stomach.Kwashiorkor is especially common is poorer

developing countries – protein rich foods are often too expensive to buy.

Children need a greater proportion of protein than adults (for growth), so they may be more likely to suffer.

Linda York

Malnutrition

Malnutrition can be the result of an

eating disorder. Even in developed countries, some psychological disorders can cause under-nutrition, e.g. anorexia nervosa and bulimia nervosa.

Linda York

Malnutrition

Anorexia nervosa leads to self starvation.Bulimia nervosa involves bouts of binge

eating, followed by self-induced vomiting.They are both usually caused by low self-

esteem and anxiety about body fat – sufferers have a poor self-image.

Linda York

Anorexia and Bulimia

These disorders can cause a host of other illnesses, e.g. liver failure, kidney failure, heart attacks, muscle wastage, low blood pressure and mineral deficiencies. Both disorders can be fatal.

Linda York

Dietary requirements Dietary requirements with respect to the

amounts of energy, protein, vitamins and mineral salts may change due to:– growth–pregnancy– amount of physical exercise–disorders such as diabetes, high blood

pressure and heart disease.

Linda York

Linda York

Benefits of fibre in the diet

Although fibre is not strictly a nutrient, it is a very important component of our diet.

Fibre rich foods are: wholemeal/wholegrain foods such as bread, cereal and flour, brown rice, wholemeal pasta, oats, beans, peas, lentils, grains, seeds, fruit and vegetables.

Linda York

Fibre

Fibre is only found in foods that come from plants.

Linda York

Too much!

Sugar Salt

• High blood pressure heart disease heart attack

• Obesity diabetes

Linda York

Calcium and iron deficiency

Calcium

• Softer bones and teeth.

• Poor blood clotting.

Iron

• Less haemoglobin produced less oxygen carried to cells less energy released person is tired (anaemia)

Linda York

Adding chemicals to food and water

Antioxidants - make foods last longer by helping to stop the fats, oils and certain vitamins from combining with oxygen in the air - this is what makes food taste 'off' - become rancid and lose colour.

Preservatives - help stop food 'go off' and mean that food can be kept safe for longer. Most food that has a long shelf-life is likely to include preservatives, unless another method of preserving has been used such as freezing, canning or drying.

Linda York

Adding chemicals to food and water

Issues include:

freedom of choice, andmass medication

Linda York

Dietary requirements for special populations

Having a balanced diet isn’t just as simple as making sure that you get all of the essential nutrients. The amount of each nutrient that you require will depend on your body’s individual needs.

Linda York

Homework

1. Complete the handouts for next week.

2. REVISE!