1. Weight Management
Chapter 14

2. Health Risks Associated with Excess Body Fat
Obesity Is associated with:
Unhealthy cholesterol and TG levels
Impaired heart function
CVD
Hypertension
Cancer
Impaired immune function
Gallbladder and kidney disease
Skin problems
Impotence, sleep disorder back pain, arthritis
Type II diabetes (strong association)

3. Body Composition Visceral Fat Subcutaneous Fat Percent Body Fat
Fat surrounding organs (within abdomen)
Subcutaneous Fat
Fat just below the skin
Percent Body Fat
Definition: Proportion of the body’s total weight that is fat

4. Evaluating Body Weight and Body Composition
Methods for Evaluating Obesity
Body Mass Index (BMI)
Calculated by the following equation: Weight in pounds X 703 / Height in inches (squared)
Under 18.5 = underweight
= healthy
25-30 =overweight
Over 30 = obese

5. Methods of Determining Percent Body Fat
Hydrostatic (underwater) weighing
Most accurate
Lean tissue is more dense than water; Fat tissue is less dense than water.
Therefore a person with more body fat will weigh less underwater and be more buoyant
Skinfold measurements
Measures thickness of fat under the skin
Electrical Impedance Analysis
Electricity prefers lean tissue
Scanning procedures
CT scan, MRI, Dual-energy X-ray produce images to view amount & location of fat
Hydrostatic (underwater) weighing
Most accurate
In this method a person is submerged and weighted under water; Percent body fat can be calculated from body density b/c muscle has a higher density than fat. This means that people with more fat tend to float and people with less fat (more muscle) tend to sink and weigh more under water
Skinfold measurements
Measures the thickness of fat under the skin. Measurements are taken at several sites and plugged into formulas that predict body fat percentages.
Electrical Impedance Analysis
Electrodes are attached to the body and an electrical current is transmitted from electrode to electrode. The electrical current favors the path of fat free tissues (prefers lean tissue). A computer calculates the fat percentages from measurements of current.
Scanning procedures
CT scan, MRI, Dual-energy X-ray are highly accurate means of assessing body composition but use expensive equipment.

7. Energy Balance Energy balance equation:
Energy in = caloric intake from food
Energy out = caloric expenditure
Resting metabolism
Digestion
Physical activity
When energy in = energy out Maintain weight
When energy in > energy out positive energy balance (Gain weight over time)
When energy in < energy out negative energy balance (Lose weight over time)

8. Body Fat distribution and Health
Apples
Men and postmenopausal women
Store fat in abdominal area
Increased risk of high blood pressure, diabetes, early-onset heart disease, stroke, cancer
Pears
Premenopausal women
Store fat in hips, buttocks, thighs
Assessed by measuring waist circumference
> 40 inches for men and 35 inches for women is considered a risk

9. Problems Associated with Very Low Levels of Body Fat
Low % body fat has been linked to problems with the Reproductive, Circulatory, & Immune systems
Female Athlete Triad
Abnormal eating patterns
Amenorrhea
Decreased bone density

10. Factors Contributing To Excess Body Fat
Genetic Factors
Genes influence body size, shape fat distribution
300 genes have been linked to obesity
Physiological Factors
Metabolism
Low BMR = Basal Metabolic Rate (number of calories you'd burn if you stayed in bed all day)
Hypothyroidism
Hormones
Leptin
Genes influence body size, shape and body fat distribution
25 to 40% of an individual’s body fat determined by genes
300 genes have been linked to obesity
Physiological Factors
Metabolism
Sum of all biochemical reactions
RMR (largest component) = energy required to maintain vital body functions
Hormones
Leptin- a hormone produced by adipose (fat) tissue that is carried to the brain and tells the brain how big or small the body’s fat stores can be. With this information the brain can regulate how much fat you can store
Fat Cells – The amount of fat the body can store depends on how many fat cells are in it. When all the body’s fat cells are filled with fat it will make more fat increasing the body’s ability to store fat. Overeating can cause the body to make more fat cells, increasing the body’s fat stores and whether or not the body gets rid of fat cells is still up for debate.
Carbohydrate Craving – may cause overeating and can lead to obesity. Animal studies have suggested that consuming carbohydrates increases brain levels of serotonin, a neurotransmitter that induces calmness. People with low levels of serotonin may consume crave and consume carbohydrates in order to experirence the improved mood and calmness

11. Factors Contributing To Excess Body Fat
Lifestyle Factors
Eating
Easy access to high calorie foods
Eating out of proportion
Physical Activity
Reduced
Psychosocial factors
Emotions
Coping strategies
Eating
Easy access to high calorie foods
Eating out of proportion
Physical Activity
Reduced
Psychosocial factors
Emotions- eating is often a way to deal with loneliness, anger, shame, sadness, etc.; obesity levels go down as income goes up; more women than men are obese at lower income levels but the oppositeis true at higher income levels
In some families, food is used as a symbol of love and caring and is an integral part of family gathering, so it is cultural too
Coping strategies

12. Psychological Problems associated with weight
Body Image
Severe body image problems
Body dysmorphic disorder (BDD)

13. Eating Disorders
Anorexia Nervosa - Failure to eat enough food to maintain a reasonable body weight
Characteristics
Fear gaining weight, distorted self-image, compulsive behaviors and rituals, excessive exercise
Health Risks of Anorexia Nervosa
amenorrhea
Intolerant of cold
Low blood pressure and heart rate
Depression and suicide
Medical complications
Disorders of the cardiovascular, gastrointestinal, endocrine, and skeletal systems

14. Eating Disorders
Bulimia Nervosa - recurring episodes of binge eating followed by purging
Characteristics:
Rapid food consumption, followed by purging; afterwards feels ashamed, disgusted, physically and emotionally drained.
Health Risks:
Erodes tooth enamel
Cardiac arrhythmia
Esophageal tearing
Rupture of the stomach
Menstrual problems
Increased depression

15. Eating Disorders
Binge-Eating - Similar to Bulimia except no Purging behavior.
Eating patterns - very rapid, eating until uncomfortably full.
Often eat as a way of coping.
Likely to be obese.
High rates of depression and anxiety