Mavhungu Nditamani
201320186
Unit 6
Life Science Lesson
Topic: Maintaining a healthy Weight
Grade: 10
Life Science: Maintaing a healthy weight 1

Lesson outcomes
 By the end of this chapter, learners should be able to:
 Define what is a healthy weight
 Calculate their Body mass index
 Define what obesity is
 Explain what implication does obesity have on a person
 Name diseases associated with obesity
Life Science: Maintaing a healthy weight 2

Continued learning outcomes
 Give possible treatments for obesity that are scientifically
proven
 Explain the impact of not eating on a body
 Define anorexia
 List the symptoms of anorexia
 Treatment of anorexia
 Tabulate the difference between obesity and anorexia
Life Science: Maintaing a healthy weight 3

Introduction
 Maintaining healthy weight has been a struggle for
centuries.
 In this struggle many people has resulted with one of the
two extreme conditions which are obesity and anorexia.
 In this chapter, we’ll learn about these two conditions.
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 Obesity is a challenge that has been going on for a long period for
long.
 It mostly affects the children and adolescents and it is on the rise
 Obesity increases chances of developing various diseases with age
 In South Africa overweight and obesity varies with age, gender
and population group.
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 There is also a great amount of people who suffer from
anorexia nervosa
 This is caused by eating very little portions of food or
exercising non-stop. In some cases not eating at all.
 Mostly those people see themselves as being very fat and
therefore want to fast to loose some body fat
 The BMI of an anorexic person is less than 18.5
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Healthy Weight
 The Body mass index (BMI) is a measurement that determine
the weight of a person and we could be able to assess it
 BMI formula:
Life Science: Maintaing a healthy weight 7

This formula will give you your body mass index (BMI). The obesity
is diagnosed when the (BMI) is 30 or more, Refer to the table below
to learn more about BMI.
Life Science: Maintaing a healthy weight 8

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Body mass index
 BMI determine whether a person falls within a healthy
weight range
 Each individual has a unique body make up.
 Variation of individual’s BMI can be based on gender and
age
 Athletes will have greater BMI because of their muscles
than body fat
 Ladies always have more fat than men
 Older people have more body fats than younger ones
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Obesity
 Obesity refers to “excessive accumulation of fat in a body to the
extent that it may affect the health and well-being of the
individual”.
 Obesity increase the risk for the development of non-communicable
diseases during childhood and adolescence
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Causes of obesity
 Genetics
o Research shows that genetic factors are a link between heredity
and obesity.
•Genes affect the amount of body fat we store and where to store,
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Consumption of high energy fast food
 Obesity occurs when a person consumes more calories
than his/her body needs.
 Excess calories are stored as fat in a person’s body
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Medication
 Drug induced weight gain increases chances of obesity
 Examples:
 diabetic treatment
 Contraceptives
 Steroids
 Anti-depressants
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Inactivity
 Lower to no physical activity levels
 Most people spend most of their time watching television
and surfing the internet
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Culture
 In most of the African cultures, the bigger a person is, the
healthier they are thought to be.
 Being fat was associated with wealth
 Japanese Sumo wrestlers are also obese people
for the sake of the game
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Diseases associated with obesity
 Diabetes
 High blood pressure
 Heart disease
 Cancer
 Decrease in life expectancy
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Possible treatment methods
 Get assistance from health professional team that may
include the physician, a psychologist or psychiatrist,
physical and exercise therapists, and dietitians amongst
others
 Surgery has proved to be the most effective method of
treatment
 Physical activity such as exercise
 Dietary change
 Weight loss medication (Prescription based)
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Prevention
 Prevention is always the best option. You can prevent
obesity by:
o Exercising regularly
o Monitoring your weight
o Eat healthy
o Regular visits to the doctor for check ups
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Anorexia
 Anorexia is a mental-disorder characterized by an endless
desire to lose weight by refusing to eat.
 Anorexia often has certain behaviors that associate with
not eating and may or may not consist of ways to “purge”
food from the victims body.
 But usually anorexia will consist of trying to lose weight
by not eating or exercising too much.
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Symptoms of Anorexia
 Dieting despite being thin – Following a severely restricted
diet. Eating only certain low-calorie foods. Banning “bad” foods
such as carbohydrates and fats.
 Obsession with calories, fat grams, and nutrition – Reading
food labels, measuring and weighing portions, keeping a food
diary, reading diet books.
 Dramatic weight loss – Rapid, drastic weight loss with no
medical cause.
 Depression and low self-esteem
 Fatigue, dry skin, headaches and hair loss
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Cause of anorexia
 Fear of gaining weight
 Desire to look like models from fashion magazines
 Wanting to feel valued based on their weight
 Emotional needs not being met
 Fear of developing into matured adults
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Effects of anorexia
 Poor circulation
 Low blood pressure
 Brittle bones
 Increased facial hair
 Loss of periods/infertility
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More effects of Anorexia
 Fainting and dizziness
 Hair loss
 Dehydration
 Kidney damage
 Low body temperature
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Sicknesses associated with anorexia
• Heart problems
• Osteoporosis
• Mental health issues
• Kidney failure
•
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Treatment for anorexia
 Seek professional help from health practitioners
 Seek assistance from friends and family
 Gaining and maintaining weight.

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References
 Jain. A., Treating obesity in individuals and populations (2005), BMJ
Knowledge
 Martinez. J.A. Body-weight regulation: causes of obesity, (2000)Department of
Physiology and Nutrition, University of Navarra
 Rob woods Johnson foundation, Overweight and Obesity Among African-
American Youths. (2010)
 Rossouw H.A, Grant C.C, Viljoen M., Overweight and obesity in children and
adolescents: The South African problem. S Afr J Sci. (2012);108(5/6), Art.
#907, 7 pages. http:// dx.doi.org/10.4102/sajs. v108i5/6.907
 Sidiropoulos. M., Anorexia Nervosa: The physiological consequences of
starvation and the need for primary prevention efforts.(2007) McGill Journal of
Medicine
 Stark. C. All about Anorexia Nervosa. (2000), The mental health foundation.
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