KEEPING HEALTHYDiet and Exercise

Summary of Specification content• Healthy diet• Know the right balance of the different foods you need and the right amount of energy.

Learning Outcomes• Evaluate information about the effect of food on health.• Explain how carbohydrates, fats and proteins are used by the body to release energy and to build cells. • State that mineral ions and vitamins are needed in small amounts for healthy functioning of the body.

Activity: food labels• Look at food labels • list the food groups needed in a balanced diet and discuss

their uses. • Sort food pictures into groups.• produce a food pyramid using food labels or a wall display

showing food groups with examples of foods.

Components of a balanced diet• Proteins• Fats• Carbohydrates• Vitamins• Minerals• Fibre• Water

• A balanced diet is eating these components in the correct proportions

Dietary requirements• Energy is provided by fat and carbohydrate intake• Dietary requirements depend on• Age• Energy demand increases until we stop growing

• Sex• Males use up more energy than females

• Activity• Physical work will use up more energy than office work.

What happens if you don’t eat a balanced diet.• What is this cartoon trying to

demonstrate?

• Can you think of any examples of health problems that arise from not eating a balanced diet?

• Give three examples and explain the effects on health.

An Unbalanced diet• An unbalanced diet could lead to• Obesity• Risks include coronary heart disease and diabetes

• Too much animal fat can lead to high cholesterol• Risks include coronary heart disease and angina

• Lack of protein in diet can lead to protein energy malnutrition

• Lack of fibre can lead to constipation and bowel cancer• Vitamin and mineral deficiencies

How Science Works• Food tests – produce a Venn diagram showing foods which have different combinations of the nutrients tested.

How Science Works• Measure the energy content of foods, eg pea and Wotsit. Evaluate effectiveness of class method and compare values with those on food packets.

Energy• Carbohydrates and fats supply most of our energy• Energy is measured in calories or joules• 1 cal = 4.2J

Comparing the energy content of food

• Energy values are quoted on the “nutritional information” panels on food packets• Look at the worksheet that describes an experiment that will help you to understand how manufacturers obtain the energy value for a food product.

PracticalMeasuring the energy content of food• You are going to investigate the energy content of different types of potato chip (a.k.a the common crisp)• Read through your handout – if there are no questions start your practical

How Science Works• Investigate the vitamin C in fruit juices (DCPIP).

Fats in our diet!• A high-fat diet can lead to obesity• Important functions of fat in the body• Protect vital organs • Energy reserve• Cholesterol is required for cell membranes

Salt in our diet!• High levels of salt are linked to high blood pressure, which are risk factors in heart disease and stroke

Upsetting the energy balance!• Energy in food is greater than energy used• Overweight people are more likely to suffer from arthritis,

diabetes, heart disease and high blood pressure

Upsetting the energy balance!• Energy taken in with our food is less than the energy we need for our lifestyle• Anorexia, deficiency diseases, malnutrition due to lack of

protein, low resistance to infection

How Science Works• Calculate BMIs.

Homework Activity• Design a healthy meal plan for a family of 2 adults and 2 children• The meal plan must include 5-a-day

• Helpful Hint• The NHS website http://

www.nhs.uk/Tools/Pages/5aday.aspx• Will do this for you – you must get a print out of your meal

plan and stick it into your book

Summary of Specification content• Metabolic rate – The rate at which all the chemical reactions in the cells of the body are carried out.

Learning Outcomes• Describe factors that affect the metabolic rate, eg the rate varies with the amount of activity you do and the proportion of muscle to fat in your body.

Summary of Specification content• Inherited factors affect health, eg metabolic rate and cholesterol level.

Learning Outcomes• Explain how inherited factors can also affect our health; these include metabolic rate and cholesterol levels.

Metabolic Rate• Metabolic rate is the rate at which all chemical reactions in your body’s cells are carried out.• Generally speaking – the higher your metabolic rate the more energy you use• The rate is affected by:-• Activity or exercise• Proportion of fat to muscle in your body• Inherited factors• Age • Metabolic rate decreases with age

Blood Cholesterol levels• Cholesterol is a fatty substance made in the liver and transported by the blood• It is required to keep our body cells functioning normally.• The cholesterol level in your body is affected by:• How much fat there is in your diet• Inherited factors

• High cholesterol levels can increase the risk of heart disease.

Summary of Specification content• Mass• A person loses mass when the energy content of the food

taken in is less than the amount of energy expended by the body.

Learning Outcomes• Analyse and evaluate claims made by slimming programmes and products.

Activities• Research: • Research different types of diets and list pros and cons.• Atkins, • Slimfast, • G.I. • Weight watchers

• Match diets to different people: • Research obesity problems in children in the UK or from another

country.• Write an article or a blog to detail lifestyle changes they must

make.

• Task:• Calculate values from nutritional information on food packets.

Summary of Specification content• Regular exercise improves your health.

Learning Outcomes• Evaluate information about the effect of lifestyle on development of diseases.

• Poster to show how lifestyle can affect health and fitness