Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Weight Management Achieving and Maintaining a Healthful Body Weight 5/9/07
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings What is a Healthful Body Weight? A healthful weight Is appropriate for your age Is maintained without constant dieting Is acceptable to you Is based on family history of body shape and weight Promotes good eating habits and allows for regular physical activity
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings What is a Healthful Body Weight? Underweight: having too little body fat to maintain health. Overweight: having a moderate amount of excess body fat.
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings What is a Healthful Body Weight? Obese: having an excess of body fat that adversely affects health. Morbid obesity: body weight exceeding 100% of normal, creating a very high risk for serious health complications.
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Evaluating Body Weight A person’s actual weight is not the only factor to consider. Determining if a person’s body weight is healthful should include: Determining the Body Mass Index (BMI) Measuring body composition Assessing the pattern of fat distribution
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Evaluating Body Weight Body Mass Index Expresses the ratio of a person’s weight to the square of their height BMI = weight (kg) / height (m) 2 BMI values below 18.5 or above 30 have increased risks of health problems
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Mortality risk vs. BMI
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Evaluating Body Weight
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Evaluating Body Weight Body Composition Measurement of body fat and lean muscle mass Can be measured by Underwater weighing Skinfold measurements Bioelectric impedance analysis Near infrared reactance Bod Pod™
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Evaluating Body Weight
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Evaluating Body Weight
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Evaluating Body Weight Fat Distribution Pattern Measured by waist-to-hip ratio and waist circumference Apple-shaped fat patterning - upper body Increased risk for chronic diseases Pear-shaped fat patterning – lower body No significant increased risk for chronic diseases
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Evaluating Body Weight
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Gaining or Losing Weight Whether a person gains or loses weight depends on Energy intake vs. energy expenditure Genetic factors Childhood weight Behavioral factors Social factors
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Energy Balance Energy balance Occurs when energy intake = energy expenditure Energy intake = kcal from food Energy expenditure = energy expended at rest and during physical activity
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Energy Balance
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Energy Balance
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Energy Balance
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Energy Intake Calculating the energy that is in a particular food Carbohydrate is 4 kcal/g Protein is 4 kcal/g Fat is 9 kcal/g Alcohol is 7 kcal/g 1 cup of quick oatmeal has 142 kcal 6 grams protein x 4 kcal/gram = 24 kcal 25 grams carbohydrate x 4 kcal/gm = 100 kcal 2 grams fat x 9 kcal/gram = 18 kcal Total kcal = 24 kcal kcal + 18 kcal = 142 kcal
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Total Energy Expenditure Total energy expenditure = basal metabolic rate (BMR) +thermic effect of food (TEF) +energy expended in physical activity
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Energy Balance Basal Metabolic Rate (BMR) Energy expended to maintain basal, or resting, functions of the body Basal metabolism is the highest proportion of total energy expenditure More lean tissue increases your BMR BMR decreases with age
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Energy Balance Thermic Effect of Food (TEF) Energy expended to process food
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Physical activity
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Genetic Factors Genetic factors account for about 25% of a person’s body fat. Different ideas have been suggested to explain the impact of genetics on body fat. Thrifty Gene Theory Set-point Theory Leptin Theory
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Genetic Factors Thrifty Gene Theory Proposes that a gene (or genes) causes people to be energetically thrifty Proposes that people with this gene expend less energy than other people and therefore gain weight A “thrifty gene” has not been identified
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Genetic Factors Set-Point Theory Proposes that each person’s weight stays within a small range (set point) The body compensates for changes in energy balance and keeps a person’s weight at their set point
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Physiologic factors Hunger Proteins released by body (hormones, peptides)
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Physiologic Factors Leptin Leptin is a hormone produced by fat cells that causes reduced food intake, reduced weight, decreased body fat Leptin is controlled by the ob gene Mutation of the ob gene causes reduced levels of leptin leading to increased food intake and reduced energy output
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Physiologic Factors Ghrelin Ghrelin is synthesized in stomach, functions as a hormone Role in appetite regulation through its actions on the hypothalamus Stimulates appetite, increases amount of food one eats
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Physiologic factors Peptide YY (PYY) PYY is produced in the gastrointestinal tract Released after meal in proportional amounts to the energy content of the meal. Functions to decrease appetite, decrease food intake May play important role in obesity
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Childhood Factors Environmental factors in childhood can influence Food choices Activity levels Later adult behaviors Childhood overweight increases the risk of heart disease and premature death as an adult.
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Behavioral Factors Food Choices The composition of a person’s diet should remain balanced. Hunger vs. Appetite Appetite, a psychological desire to eat, can cause people to overeat.
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Social Factors Social factors influencing our diet include: Family or cultural traditions Holidays and celebrations Easy access to high-fat foods Less physically active lifestyles Societal expectations of the “perfect” body
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Determining Kilocalorie Needs The most accurate way to determine your energy needs: Calculate your BMR BMR = weight (kg) x 1.0 (for men) BMR = weight (kg) x 0.9 (for women) Add the energy required to maintain your activity level to your BMR
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Achieve & Maintain Healthful Weight Healthful weight change requires Gradual change in energy intake Regular and appropriate physical exercise Application of behavior modification techniques
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Achieve & Maintain Healthful Weight Effective weight loss should include Following recommended serving sizes Reduced intake of high-fat and high-energy foods Regular physical exercise To increase energy expenditure To increase BMR
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Achieve & Maintain Healthful Weight Weight loss medications and herbal supplements: May have dangerous side effects Many have been removed from market Should only be used if a person has A BMI of 30 kg / m 2 A BMI of 27 kg / m 2 and other health risk factors
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Achieve & Maintain Healthful Weight Effective weight gain should include Eating 500 to 1,000 extra kcal/day Eating frequently throughout the day Maintaining a balanced diet, limiting fat intake to 15-30% of total energy intake Avoiding tobacco products which depress appetite and increase BMR Regular exercise with resistance training
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Protein supplements Do not increase muscle growth or strength Claim to be anabolic (increase muscle mass) Protein supplements Androstenedione (affects HDL and LDL negatively)
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Anabolic steroids Cause major health problems, including: Unhealthy changes in blood cholesterol Mood disturbances Testicular shrinkage in men Breast enlargment in men Irreversible clitoral enlargement in women
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Disorders Related to Energy Intake Underweight BMI below 18.5 kg / m 2 Increases the risk of infections and illness and can even be fatal Can be just as unhealthy as overweight
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Disorders Related to Energy Intake Overweight BMI between 25 and 29.9 kg / m 2 Increases the risks of high blood pressure, heart disease, type 2 diabetes sleep disorders, osteoarthritis, gallstones Can lead to obesity
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Disorders Related to Energy Intake Obesity and Morbid Obesity Obesity: BMI from 30 to 39.9 kg / m 2 Morbid obesity: weight that exceeds 100% of normal 5 of the 9 leading causes of death in the US are associated with obesity A multifactorial disease – many things cause obesity
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Disorders Related to Energy Intake
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Disorders Related to Energy Intake Treatments for obesity may include Low-calorie diet and regular exercise Prescription medications Surgery Gastroplasty Gastric bypass Gastric banding
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Disorders Related to Energy Intake
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Disorders Related to Energy Intake
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings Great websites for BMI calculation National Heart, Lung, and Blood Institute: BMI Calculator Centers for Disease Control: BMI Calculator and Factors that Affect BMI age.htm age.htm