Weight Management Chapter 14

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)

Body Fat Visceral Fat Subcutaneous Fat Percent Body Fat Fat surrounding organs (within abdomen) Subcutaneous Fat Fat just below the skin; not as hazardous to your health Percent Body Fat Definition: Proportion of the body’s total weight that is fat Average for Women: 25-31% Average for Men: 18-24%

Evaluating Body Weight and Body Composition Methods for Evaluating Obesity Body Mass Index (BMI): A measure of body weight that is useful for classifying the health risks of body weight (weight-to-height standard) Calculated by the following equation: (Weight in pounds /2.2) (Height in inches x0.0254)squared 18.6 - 24.9 = healthy 25-30 =overweight Over 30 = obese

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 and thus travels faster through it

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 Calories > Energy out positive energy balance (Gain weight over time) Calories < Energy out negative energy balance (Lose weight over time)

Body Fat distribution and Health Apples Store fat in abdominal area Increased risk of high blood pressure, diabetes, early-onset heart disease, stroke, cancer Pears Store fat in hips, buttocks, thighs Assessed by measuring waist circumference > 40 inches for men and 35 inches for women is considered a risk There is also WHR to consider (waist to hip ratio)

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

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/RMR = Basal/Resting Metabolic Rate (number of calories you'd burn if you stayed in bed all day) Hypothyroidism= low thyroid activity Hormones Leptin – satiety hormone

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

Psychological Problems associated with weight Body Image Severe body image problems like Body dysmorphic disorder (BDD) can exist

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

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

Eating Disorders Binge-Eating - Similar to Bulimia without purging behavior. Characteristics 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