Unit 3

Lesson 3.3 Notes

Physical Effects of Eating Disorders Video (3-minutes)

eTextbook Ch. 8: Weight Management and Eating Behaviors

Section 1: Food and Your Body Weight

Key Terms Hunger – the body’s physical response to the need for

food

Appetite – the desire, rather than the need, to eat

certain foods

Basal metabolic rate (BMR) – the minimum amount of

energy required to keep the body alive when in a rested

and fasting state

Overweight – being heavy for one’s height

Obesity – having excess body fat for one’s weight; the

state of weighing more than 20% above your recommended body weight

Why Do You Eat?

Are You Really Hungry?

Hungry – body responds physically, triggered by signals in the body (some from

digestive tract, stomach, levels of nutrients in bloodstream, some from other parts)

send messages to brain that tell you to eat

o Stomach growling

o Lightheadedness

o Inability to concentrate

Appetite – you have a desire to eat certain foods

o An imbalance between the two is bad

Satiety – feeling full after you eat

What Foods Do You Choose?

Food you choose to eat depends on:

o Smell and taste of food

o Mood

o Family traditions / ethnic background

o Social occasions

o Religious traditions

o Health concerns

o Advertising

o Cost and availability

Food Provides Energy

Carbs, fats, proteins are energy-giving nutrients

Energy is measured in units called calories

o Amount of energy (calories) in a food depends on how much

carbs, fat, protein the food contains

Carbs = 4 calories per gram

Protein = 4 calories per gram

Fat = 9 calories per gram

Extra food energy that is not needed (after eating and being broken

down in digestive system) is stored as either glycogen or fat

o Most energy stored in body is stored as fat

o Small amounts of glucose are needed for energy (that’s what

glycogen breaks down into)

Glycogen stores are limited; when used up, body proteins form glucose

The Right Breakfast Keeps You Going If you skip breakfast, you likely haven’t eaten in 16 hours or so; body must depend on

stored energy to fuel your body and brain (breakfast is a quick source of energy and

glucose for brain)

Meals w/ fat and protein keep you feeling full longer

Carbs are good energy, but you’ll feel hungry soon

Mix carbs + protein + fat to feel full and energetic longer (yogurt, cereal, fruit)

How Much Energy Do You Need? How much food energy (calories) you need depends on how much energy your body is

using

Basal metabolic rate (BMR) – amount of energy needed for basic functions (breathing,

circulating blood, growing); minimum amount of energy needed to keep you alive when

you are in a rested, fasting state (e.g. after you wake up in the morning);

o each person’s BMR is different

o boys require more calories than girls (e.g. 15 year old boy 3,000, 15 year old girl

2300)

Balancing Energy Intake with Energy Used energy balance – when the amount of food energy you take in is equal to the amount of

energy you use

o eating extra food causes weight gain

o eating less food causes weight loss

some body fat is essential for health (energy store, insulation, protecting internal

organs)

o girls 20-30% fat for body weight

o boys 12-20% fat for body weight

overweight – the term used to describe a person who is heavy for his or her height;

generally people who are overweight have excess body fat

Being Overweight Can Cause Health Problems Having excess body fat increases the risk of long-term diseases:

o Heart disease and high blood pressure

o Cancer (prostate, colon, breast)

o Type 2 diabetes

o Sleeping problems, sleep apnea

Overweight and Obesity: A Growing Problem Obesity – a condition in which there is an excess of

body fat for one’s weight (if you weigh more than

20% above your recommended weight range)

More than 60% of all adult Americans are

currently overweight and almost 30% of those

who are overweight are obese

14% of children and teens in the US are

overweight

o Increases the risk of chronic diseases

(diabetes, heart disease)

o Often caused by poor diet and inactivity

Why Are So Many People Overweight

Lack of physical activity (due to modern conveniences—driving, video games, TV)

Diet (eat too much, and high sugar and high fat); easy access to food

Life is too busy, we eat what’s convenient

What Can You Do?

Plan ahead

Exercise

Eat a healthy diet

Set realistic goals for weight loss and follow realistic diets

Review Questions

Section 2: Maintaining a Healthy Weight

Key Terms Heredity – the passing down of traits from parents to their biological child

Body composition – the proportion of body weight that is made up of fat tissue

compared to lean tissue

Body mass index (BMI) – an index of weight in relation to height that is used to assess

healthy body weight

Weight management – a program of sensible eating and exercise habits that keep

weight at a healthy level

Fad diet – a diet that requires a major change in eating habits and promises quick

weight loss

Why Do You Weigh What You Weigh? Whether you gain or lose weight easily is due to heredity (partly) – the passing down of

traits from parent to child

Genes – pieces of the hereditary material called DNA; carry info on how your body is

built and how your body works

o Can play a role w/ weight control:

Control the amount of body fat you have

Control signals of hunger and satiety

Regulate activity

If one or both parents are obese, you have a higher chance of being obese too

But genes are not COMPLETELY responsible; lifestyle plays a big role too

o Choose what you eat and how much you exercise

What Is a Healthy Weight for Me? Healthy weights are different for different people, so weight recommendations are

given on a rnage

Body Composition Body composition – a measure of the proportion of body weight that is made up of fat

tissue compared to bone and muscle (lean tissue)

o Affected by sex and age (women have more fat and fat increases w/ age)

o The term overweight doesn’t factor in someone’s body composition, so you

can’t judge someone’s weight alone to decide if fat loss is necessary

o You can be overweight, but not obese (obese people tend to have higher % of

body fat)

Skinfold thickness – method of measuring body composition; a caliper is used to pinch a

portion of skin and the underlying fat; it measures the thickness; body fat % can be

figured using a math equation

Flow of a low-level electric current through the body (measures body composition)

Body Mass Index (BMI) BMI – index of weight in relation to height that’s used to assess healthy body weight;

correlates well w/ body composition

Adult BMI should be 18.5 – 25; overweight is 25.1-29.9; obese is 30+

o Some exceptions: weight lifters

Children, Teens, and BMI Adult BMI not suitable for people under 20 years old

Harder to track overweight and underweight b/c young people grow differently

A Healthy Weight Management Plan Weight management – program of sensible eating and exercise habits that will help

keep weight at a healthy level

o Kids and teens should shouldn’t have weight loss—you should grow into your

weight

o Weight loss only necessary if weight is impacting health (high blood pressure,

difficulty breathing)

Eat Smart, Exercise More Reduce portion sizes; learn lower-calorie options

Increase exercise (60 minutes per day)

Change bad habits

o Keep a food log, exercise log

Lose Fat, Not Muscle! Appropriate weight loss is ½ to 1 pound per week (to prevent muscle loss)

Faster weight loss is usually due to water and muscle loss, not fat

To lose a pound per week, average person needs to eat 500 fewer calories each day or

burn 500 more calories each day

If You Are Underweight Consult with a doctor to make sure your low weight isn’t due to an illness

May be from eating too little or exercising too much or heredity

To gain weight, snack more frequently on nutritious foods that are high in calories

Dangerous Weight-Loss Practices Programs that promise quick fixes generally do not promote long-term weight

management

Fad Diets Fad diet – a diet that requires major changes in your eating habits and promises quick

results

Some do result in weight loss, but some are false promises

Often do not meet nutrient needs, are difficult, and boring

Diet Pills No safe diet pills exist

Surgery

A drastic method of reducing body weight

Gastric bypass – bypassing part of the stomach and sometimes the intestine; reduces

the amount of food you can eat, nutrients absorbed, or both

o Very risky

o Recommended only for individuals whose weight-related health risks are so

great that the health risks are more serious than the risk of surgery

What Should You Do? The only safe and reliable way to lose weight is to reduce portion sizes, increase

exercise, and work to change the habits that led to weight gain

Balance food intake with exercise

Work to change bad habits

No single, quick way to lose wieght

Review Questions

Section 3: Eating Disorders

Key Terms Body image – how you see and feel about your appearance and how comfortable you

are with your body

Anorexia nervosa – an eating disorder that involves self-starvation, a distorted body

image, and low body weight

Bulimia nervosa – an eating disorder in which the individual repeatedly eats large

amounts of food and then uses behaviors such as vomiting or using laxatives to rid the

body of the food

Binge eating / bingeing – eating a large amount of food in one sitting; usually

accompanied by a feeling of being out of control

Purging – engaging in behaviors such as vomiting or misusing laxatives to rid the body of

food

What Are Eating Disorders Eating patterns that are inflexible and highly structured are not normal

o E.g. never eating enough

o Dieting excessively

o Eating only certain types of foods

o Eating too much

o Not responding to natural feelings of fullness or hunger

Eating disorders – conditions that involve an unhealthy degree of concern about body

weight and shape and that may lead to efforts to control weight by unhealthy means

o E.g. starving oneself

o Overeating

o Forcefully ridding the body of food by vomiting or using laxatives

Body Image and Eating Disorders Body image – how you see and feel about your appearance and how comfortable you

are with your body

o Changes with mood, environment, experiences

o Affects your eating habits and health

Eating disorder can cause a distorted body image (people don’t see themselves as they

really are)

Culture and society define what we think of as perfect (e.g. Marilyn Monroe in the

1950s-curvy and full figured); people on magazines, movies, and ads represent 1% of the

population – i.e. they’re not realistic!

A Healthy Body Image Accept your body’s appearance and abilities

Listen to what your body tells you

Weight and body shape changes frequently in teen years

A Closer Look at Eating Disorders Eating disorders:

o Thousands of people die each year from complications related to eating

disorders

o Often develop during adolescence

o Contributing factors: genetics, culture, personality, emotions,

family, athletics (gymnastics, figure skating, wrestlers,

dancers, models)

o Most common in young women, overachievers,

perfectionists, adolescents who have a difficult family life

Common Eating Disorders 3 most common: anorexia nervosa, bulimia nervosa, binge eating

disorder

Anorexia nervosa – an eating disorder that involves self-starvation, a

distorted body image, low body weight

Bulimia nervosa – an eating disorder in which an individual repeatedly eats large

amounts of food and then uses behaviors such as vomiting or using laxatives to rid the

body of the food

Bingeing (binge eating) – eating of a large amount of food in one sitting; bingeing may

be followed by purging (vomiting or misusing laxatives to rid the body of food)

Could You Be at Risk? Prefer to eat alone

Being overly critical about body size and shape

Thinking about food often

Weighing yourself every day

Eating a lot of “diet” foods

Trouble in home/school/friends due to concerns about food or your appearance

TALK WITH SOMEONE

Getting Help Professional help from physicians, psychologists, nutritionists is essential to manage and

recover from an eating disorder

People often deny that they have a problem and believe their behavior is normal and a

chosen lifestyle; may not seek help early enough

Encourage your friend to seek help; speak to them in private; listen to them; tell an

adult; when life is in danger, there is no confidentiality to keep

Review Questions

Section 4: Preventing Food-Related Illnesses

Key Terms Food allergy – an abnormal response to a food that is triggered by the immune system

Lactose intolerance – the inability to completely digest the milk sugar lactose

Food-borne illness – an illness caused by eating or drinking a food that contains a toxin

or disease-causing microorganism

Cross-contamination – the transfer of contaminants from one food to another

Food and Digestive Problems If you have severe or persistent symptoms related to food / digestive problems, see a

doctor

Heartburn

Heartburn - Burning feeling in your chest after a large meal

Caused by stomach acid leaking into the esophagus (the tube that connects your throat

with your stomach)

Main cause is overeating foods high in fat

Stress and anxiety can also cause heartburn by increasing the amount of acid made by

stomach

Prevent by eating small, low-fat meals frequently and by not lying down soon after

eating

Ulcers

Ulcers – open sores in the lining of the stomach or intestine

Most are caused by bacterial infection of the stomach lining

Treatable with antibiotics

Stress and unhealthy diet can make ulcers worse

Embarrassing Digestive Problems Gas – produced when bacteria living in the large intestine break down undigested food

o Beans contain a large amount of indigestible material; you can’t digest it, but

the bacteria that live in your large intestine eat it up, break it down, and the by-

product of this is gas

o Flatulence – the buildup of gas and a bloated feeling

Diarrhea – frequent watery stools

o Can be caused by infections, medications, reactions to foods

o Occasional diarrhea is common and mostly harmless

o Prolonged diarrhea can lead to dehydration

(when water in body decreases enough to cause a drop in blood

volume)

Makes it difficult for the blood to carry nutrients and oxygen around the

body

Life threatening

o Dehydration from diarrhea kills millions of kids in developing worlds each year

Constipation – difficulty having bowel movements or having hard, dry stools

o Caused by weak intestinal muscles, a diet low in fiber or fluid

o Prevented by getting plenty of exercise, drinking lots of water, eating diet high

in whole grains, fruits, veggies

Food Allergies Food allergy – abnormal response to a food that is triggered by the body’s immune

system;

o Common causes:

Peanuts

Eggs

Wheat

Strawberries

Soy foods

Seafood

Milk

Immune system reacts to the food as if it were a harmful microorganism

Causes symptoms throughout the body (sometimes mild, sometimes life-threatening)

o E.g. upset stomach, hives, runny nose, body aches, difficulty breathing, drop in

blood pressure

o Sometimes symptoms are immediate, sometimes take 24 hours to appear

Is It a Food Allergy? True food allergies are relatively rare

To see if symptoms are due to a specific food, cut from your diet for 2-4 weeks, then eat

a small amount of one suspected food (do this in a doctor’s office, in case of severe

reaction)

o Don’t do this with peanut allergy b/c it can be deadly

Managing a Food Allergy Avoid eating food you’re allergic to

Ask about ingredients

Look at food labels

Carry epinephrine – a hormone injection that can prevent a fatal reaction

Food Intolerances Food intolerances do not cause a specific reaction of the immune system (like an allergy

does); they irritate the intestine

Lactose intolerance – reduced ability to digest the milk sugar lactose; not a milk allergy;

o lactose is found in milk and cheese, among other dairy products

o symptoms occur b/c undigested lactose passes into large intestine where it is

digested by bacteria that produce acids and gas from the lactose

o rare in children but affects ¼ of American adults

o varies based on world population (e.g. 5% of people in northwestern Europe,

nearly 100% of people in some parts of Asia and Africa)

Food-Borne Illness food-borne illness – an illness caused by eating or drinking a food that contains a toxin

or disease-causing microorganism

caused by any type of contamination in food

most in US caused by eating food contaminated with pathogens (bacteria, viruses, fungi,

parasites)

most cases are mild

most cases of food-borne illness are due to foods that are prepared or eaten at home

Is It the Flu? Symptoms of food-borne illness (nausea, vomiting, diarrhea) often thought to be

stomach flu

Symptoms may appear as soon as 30-minutes after eating a contaminated food or may

take several days or weeks to appear

Rest and take plenty of fluids; symptoms last a day or two

Can be life-threatening for young kids, pregnant women, elderly, the ill

Preventing Food-Borne Illness Selecting storing, cooking, handling food properly prevents food-borne illnesses

Cross-contamination – transfer of contaminants from one food to another

o E.g. using the same cutting board for raw chicken and vegetables for a salad;

when raw and cooked foods are stored together

o Can happen in food-processing plants and

restaurants; could affect hundreds of people, so

there are strict federal hygiene regulations that

apply

Replace and wash dishcloths and hand towels frequently

Keep fridge at 41-degrees F

Wash hands, cooking utensils, surfaces w/ warm soapy

water

Cook food to recommended temps to kill microorganisms

Review Questions

Web Resources: Understanding Behaviors and Signs

I Think My Friend Has an Eating Disorder:

Why Diets Fail:

Current / Common Fad Diets: