Unit 10: Body Weight and Weight Management

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Unit 10 Body Weight and Weight Management
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My qualifications
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Key Definitions

• All the following definitions are based on the
  concept of an ideal weight
• Medical definition the weight at which the
  individuals health risk is lowest
• Aesthetic definition varies between culture,
  individuals

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Key Definitions

• An overweight individual exceeds their ideal
  weight
• An overfat individual exceeds the recommended
  amount of body fat by a certain margin
• Obesity is a large excess above overfatness

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It is possible to be overweight and not be
overfat Think Arnold
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Methods of Determining ideal weight
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Height Weight TablesIdeal weight as measured by
MetLife insurance company
Doesnt consider body composition Only intended
for people 25-59 Sample they used may not be
representative The weights suggested for tall
people are unreasonably low
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Body Mass Index (BMI)

• BMI (body mass in kg)/ (height in metres)²
• Ex. My BMI (155 lbs x 1kg/2.24 lbs)/ (1.7 m)²
• BMI 23.94
• BMI above 25 overweight
• BMI above 30 obese
• Again, poor at accounting for body composition
• How much muscle do you have???
• However, simple to figure out
• Good for population-based analysis

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BMI Classification
James, 2001
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More Reliable Methods for Estimating Body Fat

• Underwater weighing
• Sum of skinfolds
• electrical impedance
• CAT scan

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Obesity Trends/ Statistics
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The Changing Size of North America
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Healthcare Burden of Obesity
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Health Risks of Overweight

• cardiovascular disease (CVD)
• hypertension
• Type II Diabetes
• pulmonary disorders
• sleep disorders (e.g. SLEEP APNEA)
• gout
• various cancers
• osteoarthritis
• early mortality
• depression

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Prevalence of obesity

• Higher in
• Males compared to females
• However, women are more dissatisfied with weight
  than men
• Even though their BMIs are lower, are less
  overweight and have a higher prevalence of
  underweight
• Older people
• Poorly educated adults
• Rural (the country) compared to urban (the city)
  habitants
• Low income groups vs. high income groups

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Causes of Obesity
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Causes of ObesityCausal Web
Kumanyika, 2002
Too linear, no feedback loops
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Causes of ObesityForesight Model
Take Home Message Obesity is complex!
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Feedback loops in the Foresight model convey the
complex nature of obesity and the various
interactions at play
Ex. Food Consumption
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Foresight Causal Obesity Nodes

• Food Consumption
• Individual Physical Activity
• Individual Psychology
• Social Psychology
• Physical Activity Environment
• Food Production
• Physiology

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Causes of Obesity Food Consumption/ Individual
Physical Activity (Positive Energy Balance)
Physical Inactivity has increased
Food consumption has increased
Energy Balance energy intake energy
expenditure
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Causes of Obesity Individual Psychology

• Psychological and cultural factors
• Hunger center in brain
• Receives sensory cues such as smell, sight, taste
  of food
• Constantly bombarded with pro-food consumption,
  anti-activity stimuli
• Receives cues from stomach when full
• Food sometimes represents love, happiness and
  security
• Food consumption and physical activity levels
  are typically learned behaviours. If a behaviour
  is central to a persons normal behaviour, like
  smoking, it is often very difficult to change.

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Causes of Obesity Social Psychology

• Obesigenic behaviour spreads through social
  networks based more on psychosocial relations
  than biological or environmental relations
• Close friendship with an obese person predicts
  obesity more than living near obese people or
  familial relation to an obese person (Christakis
  2007)

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Causes of Obesity Food Production(Social
Psychology)
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Causes of Obesity Food Production
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Causes of Obesity Physical Activity Environment
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Causes of Obesity Physiology

• Metabolic factors associated with lt 2 cases of
  obesity
• ex. Thyroid gland malfunction
• Hormonal factors hormones can influence appetite
  and metabolic rate improper sleep, poor diet can
  affect their levels
• Genetic predisposition genes that influence
  appetite and metabolism may have mutations

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Is it physiologically more difficult to lose
weight after it is gained?

• The more you eat, the more your stomach learns to
  accepts a larger amount of food before its
  stretch signals fullness
• Fat gain occurs through hyperplasia (increased
  fat cell numbers) and hypertrophy (increase in
  size)
• Fat loss occurs through hypotrophy ONLY
• Which means once you gain fat cells, they never
  go away, they only get smaller!!!
• Increase activity of lipoprotein lipase (LPL), a
  molecule that stores fat, with weight loss!

Doesnt that suck????!!!!
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Why do some people gain weight easily, while
others do not?

• Thermogenic effect theory/thrifty gene hypothesis
• Obese people are better at converting food to
  tissue
• Healthy weight people may waste energy as heat
• Set point theory weight and body fat maintained
  around a narrow margin
• Metabolism speeds up when weight is gained, slows
  down when weight is lost
• Evidence some prisoners who were overfed never
  gained weight, metabolic rate increased

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Eating disorders

• Anorexia nervosa
• Bulimia nervosa
• Binge Eating Disorder
• Night Eating Syndrome
• Sleep-related Eating Disorder

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Eating Disorders by the numbers

• Lifetime prevalence (2002)
• Anorexia- 0.9 women, 0.3 men
• Bulimia- 1.5 women, 0.5 men
• Binge eating disorder- 3.5 women, 2.0 men

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Anorexia Nervosa

• Anorexia lack of appetite
• Nervosa means that it is a psychiatric disorder
• Those affected
• Have an intense fear of getting fat
• Have a distorted body image
• Do not understand how bad it is or why it started
• Often think being thin is linked with beauty
  and/or perfection
• Can slow growth and cause long term effects if
  during adolescence
• Highest mortality rate of any psychiatric
  disorder!

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Bulimia nervosa

• Bulimia great hunger
• Involves periods of extreme overeating (binging)
  followed by energy depletion either by vomiting,
  laxatives or excessive exercise
• Warning Signs include
• Preoccupation with food
• Distorted perception of body weight
• Frequent dieting
• Medical risks include
• Tooth decay
• Stomach rupture
• Tears in the esophagus
• Irregular heart beat

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Binge Eating Disorder
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Eating Disorders

• Night Eating Syndrome
• The typical person with this controversial
  disorder
• Skips breakfast
• Consumes approx half of their Calories after
  dinner
• Binges on foods that are typically
  carbohydrate-dense
• Suffers from depression/anxiety (guilt
  exacerbates condition)
• Has difficulty sleeping
• Sleep-Related Eating Disorder
• A person with this disorder gets up in a
  sleep-walking state and binges on excessive
  amounts of Calories
• Will eat strange combinations of food they would
  typically never consume

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Eating disorders

• Food is typically not the problem
• Often a larger psychological issue is at its base
• Obsession with perfection
• Distorted body image
• Child abuse physical or verbal
• More often than not affects females

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Body dissatisfaction and weight

• A significant portion of 5-year-old girls
  associate a diet with food deprivation, weight
  loss and thinness
• 29 of girls in grade 10 engage in weight loss
  behaviour
• 40 of grade 10 girls perceived themselves as too
  fat
• Girls who are teased are 1.5 times more likely to
  engage in extreme weight loss measures
• Adolescent girls who diet are 324 more likely to
  be obese than those who dont!! (Stice, 1999)

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Body Image Rant
Take home message You are not your body! Looks
fade, so it is critical to not base your self
worth on your appearance. Take care of yourself
for your health! Confidence is beautiful! Be
proud of who you are and the body that you were
given, we are all beautiful in our own ways
(super corny, but true!)
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Weight Management
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Poor methods of Weight Reduction

• Fad diets a miracle way to drop a lot of
  weight, often in a short period of time
• Most are only effective because they are a
  disguise for a low-calorie diet
• Often you may lose weight in the form of body
  water, muscle, not fat
• not nutritionally balanced
• Often too severe a reduction in caloric intake is
  prescribed
• Can actually lower metabolic rate!
• Cannot be maintained for long term

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Poor methods of Weight Reduction

• Diuretics to increase urination
• Stimulants to suppress appetite
• Massage no evidence to support waste of time!
• surgery
• Jaw wired shut
• Stomach stapled
• Intestinal bypass
• liposuction

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Guidelines for Sound Weight control
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Improve your Diet

• Balance is the key!You should not be losing more
  than 1-2 lbs per week
• More than this often results in future weight
  gain
• A 500 kcal drop per day is recommended
• There are many effective weight loss regimes
• Caloric intake should be reduced
• Portion control, nutrient dense foods, filling
  foods
• Dont lie to yourself about what you are
  consuming!
• Be aware of whats in what you are eating (see
  next slide)

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Food Item Energy (kcal) Fat (g)
McDonalds French Fries regular 570 30
McDonalds Big Mac 540 29
McDonalds Double Quarter Pounder 740 42
Burger King Whopper 670 39
Wendys Baconator 830 51
McDonalds McChicken 360 16
Burger King Tendergrill 510 19
Burger King Onion Rings 500 25
Subway 6 Meatball Marinara 580 23
Subway 6 Philly Cheesesteak 520 18
Dairy Queen Turtle Pecan Cluster Blizzard Large 1480 84
Chocolate Extreme Blizzard Large 1430 68
Starbucks Caffe Vanilla Frappuccino Blended Beverage 16 oz 390 11
Caramel Macchiato with whole milk (16 oz) 270 10
White Chocolate Mocha 430 15
Tim Hortons Boston Cream Donut 250 8
Tim Hortons Walnut Crunch Donut 360 23
Tim Hortons Chocolate glazed timbit 70 2.5
Tim Hortons Chocolate Macadamia Nut cookie 240 12
Tim Hortons Iced Cappucino (small) with cream 250 11
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Changing eating habits

• Its about the way you eat too!
• Dont shop while hungry
• Dont leave tempting food in sight
• Eat slowly
• Wait 20 minutes before eating again
• Buy smaller plates
• Have a food that signals the end of your meal
  (ie. Small chocolate)
• Eat more, but smaller meals throughout the day to
  control hunger
• Dont skip breakfast

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Improve level of Exercise

• Increases caloric consumption, boasts metabolism
• Exercise helps maintain muscle mass, which allows
  for greater metabolic rate
• Gives a toned look
• Helps relieve depression and anxiety
• Must think of it as a permanent change!
• Find activities you enjoy that you will
  incorporate into the rest of your life

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Peer Group Support/Psychological Modification

• Group weight loss programs can be helpful
• Emotional eating can disguise an underlying
  emotional conflict, counselling may help
• Everyone has a general idea of how much they
  should exercise/ eat. This does not change
  behaviour!
• You have to change the way you think, and that
  isnt easy!
• Keeping a journal of your thought
  processes/talking to others can help