sport books publisher1 weight management: finding a healthy balance chapter 12

Sport Books Publisher 1

Weight Management: Finding a Healthy Balance

Chapter 12


Objectives To discuss the differences between

overweight and obesity and implications for health

To present the concept of caloric balance in weight control

To examine the role of exercise and lifestyle modification in maintaining a healthy weight

To gain familiarity with the consequences of dieting and eating disorders

To set and evaluate personal goals for maintaining a healthy weight


Introduction More than 35% of

Canadian adults are considered overweight or obese

More than 30% of Canadian children are considered overweight or obese


Introduction Physical activity has

been engineered out of day-to-day life

The food environment has become more “toxic” by the day

Eating disorders have emerged due to social pressures to be thin


Energy-Balance Equation


Energy-Balance Equation Body weight is influenced by:

• Energy expended through physical activity • Energy gained through dietary intake

Energy is measured in the form of Calories

This is expressed by the ‘energy-balance equation’


The left side represents Calories consumed The right side represents Calories expended through

physical activity or exercise This situation depicts a balanced energy equation - a

stable weight is achievedCalories consumed = Calories expended

Weight Stability


Calories consumed beyond the body’s needs are stored as fat

Weight gain occurs when energy consumed exceeds energy expended through physical activity

Calories consumed > Calories expended

Weight Gain


Calories expended through physical activity must exceed Calories consumed in food for weight loss to occur

Calories consumed < Calories expended

Weight Loss


Energy-Balance Equation Some people want to put on a few

pounds to look better, or to “bulk up” for athletic events

Healthy weight gain is best achieved through a regimen of increasing (healthy) food intake while participating in a strength-training program to develop lean muscle tissue


Energy Needs of the Body A large amount of energy must be

consumed by the body in order to carry out vital functions such as:• Blood circulation• Respiration• Brain activity


Basal Metabolic Rate (BMR):

The minimum amount of energy the body requires to carry on all vital functions


Basal Metabolic Rate BMR varies throughout the life cycle BMR is generally higher at birth and

increases until age 2, after which it declines as life progresses

Other factors affecting BMR:• Body composition• Physical fitness• Sex• Sleep• Pregnancy• Body temperature• Age


Exercise and Weight Management

The amount of energy expended through physical activity depends on:• Volume of exercise (time, number of

workouts)• Intensity of exercise• Type of exercise


Exercise and Weight Management

In order to efficiently lose weight, exercise should be combined with controlled eating patterns that involve Calorie reduction


Benefits of Exercise Strengthens the heart Improves endurance Provides a means of managing stress Helps prevent osteoporosis Burns Calories Increases metabolic rate


Benefits of ExerciseWeight management is easier

when an exercise regimen is included

Greater lean muscle mass, decreased fat mass, and a higher level of fitness are associated with higher levels of metabolism

A higher metabolic rate allows you to eat more without gaining weight


Body Composition


Body Composition

There are three interrelated aspects of the human physique:• Size (volume, mass, surface area, length)• Structure (skeletal, muscular, fat

arrangement and distribution)• Composition (amount of fat, muscle, bone)

Body composition is one of the major components of physical fitness


Body Composition

Most common method used in body composition analysis is the ‘Two-Component’ model of the body

This model includes:• Lean body mass (LBM)• Fat body mass• Total body fat (TBF)


Lean Body Mass Refers to the ‘non-fat’ or ‘fat-free’

component of the body Includes skeletal muscle, bone, water May represent a biological lower limit

beyond which health is compromised Excessive leanness may increase a

female’s chances of developing amenorrhea (absence of menstruation)

Amenorrhea includes a reduced production of estrogen, which may also increase a female’s chances of developing osteoporosis


Lean body mass is calculated as follows:

LBM = TBM -TBF Lean body mass = Total body mass - Total body fat

TBF is calculated as follows:

TBF = TBM x %BODY FAT 100


Fat Body Mass

Can be divided into two types of fat:

1.Storage Fat (SF)

2.Essential Fat (EF)


1. Storage Fat

Fat that accumulates as adipose tissue


1. Storage Fat

Serves as an energy reserve


1. Storage Fat

Cushions and protects internal organs


1. Storage Fat

Mainly subcutaneous distribution


1. Storage Fat

Average male storage fat = 12%


1. Storage Fat

Average female storage fat = 15%


1. Storage Fat

Excess fat is associated with numerous health

problems


2. Essential Fat

Required for normal physiological functioning


2. Essential FatPresent in 1. Bone marrow

2. Heart

3. Lungs

4. Liver

5. Spleen

6. Kidneys

7. Intestines

8. Muscle

9. Central nervous system


2. Essential Fat

Comprises about 3% of body weight for the

average male


2. Essential Fat

Comprises about 12% of body weight for the

average female


2. Essential Fat

Gender-specific essential fat is located in the mammary glands, pelvic region, and is involved in hormone-related functions and pregnancy


Measuring Body Fat

Direct Measurement

Indirect Measurement


Direct Measurement

Measuring Body Fat

Involves grinding tissue

Measures fat via chemical analysis

Impractical for living organisms

Used on cadavers


Indirect Measurement

Measuring Body Fat

Skinfold calipers

Hydrostatic weighing

Bod-Pod Bioelectrical

impedance DEXA


Skinfold Calipers


Skinfold Calipers Measures skinfold thickness to predict

or estimate total body fat Based on the assumption that

subcutaneous fat is directly related to total body fat

Accuracy is ± 3% when performed correctly


Hydrostatic Weighing


Hydrostatic Weighing Determines body density to be used in

further equations that calculate percent body fat

Based on Archimedes’ principle of water displacement - an object submerged in water yields a buoyant force equal to the weight of water displaced


Hydrostatic Weighing Bone and muscle have a greater density than

water Fat is less dense than water Thus, a person’s relative buoyancy is

positively correlated with body fat That is, a person with a higher body fat

percentage is less dense (weighs less in water) than a lean individual


Hydrostatic Weighing To calculate body fat, the

following measurements are needed:

1. Body weight on land2. Underwater body weight3. Water density at the

performed temperature4. Residual lung volume

More accurate measure


The Bod-Pod


The Bod-Pod Very expensive method Very accurate measure May facilitate measuring large or

heavy individuals because it does not involve underwater submersion


Bioelectrical Impedance (BIA)


Bioelectrical Impedance (BIA) Based on differences in electrical

conductivity between fat-free mass and fat mass


Bioelectrical Impedance (BIA) Percent body fat is calculated from

measures of body density determined by passing an electrical current through the body


Bioelectrical Impedance (BIA)BIA is influenced by

the subject’s hydration level

The more hydrated one is, the leaner the BIA measurement will be


Dual Energy X-Ray Absorptiometry (DEXA)


Dual Energy X-Ray Absorptiometry (DEXA)

Can be used to determine body composition Can also measure bone density (bone

mineral content)


Body Mass Index (BMI) Can be used as an easy, inexpensive method

for determining an individual’s healthy body weight

Considers weight (kg) and height (m)

BMI = Weight (kg) [Height (m)]2

A BMI nomogram can also be used to

determine BMI, it looks like this…


Body Mass Index (BMI)


Three general ranges:1. Underweight2. Healthy or Acceptable Weight3. Overweight

• Severe Overweight• Morbid Obesity

BMI score > 30 is classified as obese and associated with an increased risk of developing health problems

Risk of developing health problems is also associated with BMI’s classified as being within the underweight range




The BMI is intended for men and women aged 20-65

It is not intended for:1. Babies2. Children3. Teenagers4. Pregnant women5. Very muscular people, such as athletes


Somatotyping The human body

is composed of:1. Roundness2. Muscularity3. Linearity Various sports

require sport-specific body types for achieving optimal performance


Somatotyping Endomorphs exhibit a round appearance

and a predominance of the gut and visceral organs

Common sports that require this body type include wrestling, weight-lifting, and throwing events


Somatotyping Mesomorphs exhibit a predominance of

muscle Common sports that require this body

type include body building, swimming, and decathlon


Somatotyping Ectomorphs exhibit a predominance of

linearity and tend to be tall and thin Common sports that require this body

type include marathon, basketball, horse-racing, and high-jump


Obesity


Obesity

Having an excess of body fat beyond some particular standard


Obesity To be classified as obese (ages 17-

50yrs):• Body fat percentage > 20% for

males• Body fat percentage > 30% for

females Obesity has reached epidemic

proportions in the Western world 35% of Canadian men and 27% of

Canadian women are considered obese


Obesity Involves many factors:

1. Environmental2. Social3. Psychological4. Genetic


Obesity There are numerous health problems

associated with obesity, including:

1. Coronary heart disease2. Stroke3. Hypertension4. Diabetes5. Osteoarthritis6. Some cancers


Creeping Obesity

Obese individuals are often viewed as gluttonous

They generally do NOT consume large amounts of calories

Physically active individuals have been shown to consume more calories than obese individuals


Creeping Obesity Obesity is often the

result of too little activity rather than overeating

This is what leads to ‘creeping obesity’

Creeping obesity is the result of a long-term change in energy balance that results in gradual fat gain over a period of time


Misleading Norms Weight norms must be interpreted with

caution Overweight does not necessarily mean

obese Body composition is important when

making this distinction Being ‘overweight’ because of a large

lean mass is not associated with the health problems linked to obesity


Weight-Loss Industry Has become a billion-dollar industry as

obesity rates rise Many fad diets exist such as

• High-protein, low-carbohydrate diets• High-carbohydrate, low-protein diets• Limited food choice diets

Most of these diets are ineffective and CAN BE HARMFUL


Weight-Loss Industry Following

Canada’s Food Guide and engaging in regular physical activity appears to be the best approach to weight management


Consequences of Dieting

Cultural pressures to be thin and the stigma of being overweight have resulted in many young people engaging in dieting and abnormal eating behaviours


Consequences of Dieting Chronic dieting can

lead to:1. Retardation of

physical growth2. Menstrual

irregularities in females

3. Lowered metabolic rate

4. Development of eating disorders


Eating Disorders


Eating Disorders Two major eating disorders within the

general population:

1. Anorexia Nervosa

2. Bulimia Nervosa

A related syndrome is known as ‘Binge Eating Disorder’ (BED)

Eating disorders also occur in male and female athletes


Eating Disorders Factors involved in the development of

eating disorders include:• Dissatisfaction with body image• Distortions in thinking• Perfectionist beliefs• Excessive self-criticism• Fear of fat• Excessive dieting• Preoccupation with food


Anorexia Nervosa

Failing to eat an adequate amount of food to maintain a reasonable body weight

Avoidance of food Engaging in

excessive vigorous exercise


Anorexia Nervosa Symptoms Typically, weigh less

than 85% of normal weight

Dry skin Amenorrhea Reduced bone mass Brittle nails Carotene pigmentation

(yellowish appearance of the palms and soles of the feet)


Bulimia Nervosa Characterized by

continual episodes of binge eating followed by purging

A binge involves eating large amounts of food in a discrete period of time

After a binge, vomiting is induced and/or laxatives are used

May also involve excessive exercise as a form of purging


Bulimia Nervosa Symptoms Body weight is often normal Secretive eating patterns Nervous or agitated behaviour

immediately after eating Loss or gain of extreme amounts of

weight


Binge Eating Disorder (BED) Involves ingesting

large amounts of food without purging

Is encouraged in some sports such as sumo wrestling and football

Leads to obesity in most cases


Eating Disorders Among Athletes

Athletes competing in sports with weight classes try to “make weight” in lower weight classes to gain a competitive edge

Often stems from a performance objectives rather than issues of self-esteem or body image

Sports include wrestling, horse racing (jockey), rowing, boxing, weight-lifting, etc.

sport books publisher1 weight management: finding a healthy balance chapter 12

Documents

healthy weight slide

weight gain slide

sport books publisher7

weight loss slide

weight stability slide

energy balance equation

physical activity energy

physical activity calories