Chapter 9
Weight Management: Overweight, Obesity, and
Underweight
Overweight and Obesity
Major health problem in the U.S.Prevalence continues to increaseDefined by BMI of 25 or greaterEpidemic is worldwide
Fat Cell Development
Energy in exceeds energy out Stored in fat cells of adipose tissue
Body fat Number and size of fat cells
Energy out exceeds energy in Fat cell size decreases; no change in number
Fat Cell Metabolism
Lipoprotein lipase (LPL) activity Storage of triglycerides Obese people vs. lean people Activity in varying body regions
Enzyme activity releasing and breaking down fat
Fat oxidation is not efficient
Causes of Overweight & Obesity – Genetics &
EpigeneticsCausative role of genetics
Genetic influences do seem to be involved
Genetics may determine predisposition to obesity
Human genomeObesity gene
Codes for the protein leptin Locations of leptin secretion
Causes of Overweight & Obesity – Genetics &
EpigeneticsObesity gene
Genetic deficiency of leptin or genetic mutation Leptin resistance Roles in the body
Energy regulation Others
Causes of Overweight & Obesity – Genetics &
EpigeneticsAdiponectin
Secreted by adipose tissue Inverse correlation with body fat Benefits
Ghrelin Promotes positive energy balance Inverse correlation with body weight Roles in the body beyond energy regulation
Causes of Overweight & Obesity – Genetics &
EpigeneticsPYY
GI cells secrete in proportion to kcalories consumed Signals satiety and decreases food intake
Ideal diet Maintain satiating hormones Minimize appetite stimulating hormones Low in fat and rich in fiber
Causes of Overweight & Obesity – Genetics &
EpigeneticsUncoupling proteins
Proteins involved in energy metabolism Two types of fat
White adipose tissue Brown adipose tissue
Uncoupling proteins found in both types of fat Influence basal metabolic rate (BMR)
Causes of Overweight & Obesity – Environment
Encountered daily circumstances Interaction between environment and genetics
Overeating Present and past eating and activity patterns
influence current body weight Availability Serving sizes
Physical inactivity Life requires little exertion Inactivity contributes to weight gain and poor health DRI for prevention of weight gain
Problems of Overweight and Obesity – Health Risks
Three indicators BMI Waist circumference Disease risk profile
Factors taken into account
Beneficial weight loss Health status Motivation
Problems of Overweight and Obesity – Health Risks
Overweight in good health Sometimes health is not the motivation for weight loss
Obese or overweight with risk factors Two or more risk factors
Obese or overweight with life-threatening condition Recommendation to lose weight
Problems of Overweight and Obesity – Perceptions &
PrejudicesMost obese people do not successfully lose
weight and maintain the lossSocial consequences
Jobs, school, and in social situations
Psychological problems
Problems of Overweight and Obesity – Dangerous
InterventionsIntervention dangersDiet books and weight-loss programs
Little success with weight loss maintenance
Fad dietsWeight-loss productsHerbal products
Laws for dietary supplements
Other gimmicks
Aggressive Treatments for Obesity – Drugs
Strategies for weight reduction depend on: Degree of obesity Risk of disease
Use drugs as part of long-term comprehensive weight-loss programs Assist with modest weight loss
Drugs approved by FDA for obesity Sibutramine Orlistat Phentermine and diethylpropion Other drugs
Aggressive Treatments for Obesity – Surgery
Clinically severe obesity 200,000 surgeries performed each year
Reduces food capacity of stomach Effectively limits food intake
Reduce production of ghrelinHealth-related benefitsLong-term safety and effectivenessLiposuction
Weight Loss Strategies
Successful strategies Small changes Moderate losses Reasonable goals
Reasonable rate of weight loss
Benefits of modest weight lossIncorporation of healthy eating and physical
activity
Wt Loss Strategies – Eating Plans
Be realistic about energy intake Provide less energy than is needed Goal: nutritional adequacy without excess Breakfast frequency
Nutritional adequacy Minimum of 1200 kcalories a day
Eat small portions Eat less food at each meal; structured meal
replacement plans Feel satisfied, not stuffed
Lower energy density
Wt Loss Strategies – Eating Plans
Remember water Assistance with weight management
Focus on fiber Low in energy and high in nutrients; require effort to
eat
Choose fats sensibly Energy density and satiation
Select carbohydrates carefully Artificial sweeteners
Watch for empty kcalories Fat, sugar, and alcohol
Wt Loss Strategies – Physical Activity
Best approach to weight management Moderate physical activity plus activities of daily life
Combination of diet and physical activity Lose more fat Retain more muscle Regain less weight
Reduction of abdominal fat
Wt Loss Strategies – Physical Activity
kCalorie expenditure Body weight, intensity, and duration
Greater the energy deficit, greater the fat loss
Discretionary kcalorie allowanceMetabolism
Speeds up with activity Immediate and long-term benefits
Wt Loss Strategies – Physical Activity
Wt Loss Strategies – Physical Activity
Body composition Fat decreases and lean body mass increases Strength-training exercises
Appetite control Delayed appetite Inappropriate appetite
Psychological benefits Self-esteem
Choosing activitiesSpot reducing
Wt Loss Strategies – Environmental Influences
Factors surrounding eating experience and the food itself
Atmosphere Pleasant and comfortable equals more food
Accessibility Less effort needed to obtain food, more food eaten
SocializingDistractions
Wt Loss Strategies – Environmental Influences
Presence Sight, smell, or thought of food can prompt eating
Multiple choice Large assortments of foods increase consumption
Package and portion sizesServing containers
Weight Loss Strategies – Behavior & Attitude
Behavior modification Positive, matter-of-fact attitude
Become aware of behaviors Keep record
Change behaviors
Weight Loss Strategies – Behavior & Attitude
Cognitive skills Problem solving Cognitive restructuring
Personal attitude Understand personal relationship with food Sound emotional health
Support groups
Weight Loss Strategies – Weight Maintenance
Successful weight loss Plateau
Prevalence of successful weight loss Difficult to determine
Weight lossComponents of successful weight lossChanges in metabolismTakes more to prevent weight regain than to
prevent weight gain
Preventing Weight Gain
Preventing weight gain would benefit many people
Strategies are similar to losing weight Start earlier
Public Health Programs
Possibly change environment through public health law
Stretch beyond individual
Underweight
Affects no more than 5% of U.S. adultsWeight gain is a matter of healthWeight gain may be difficultDemand for energy contributes to
underweightDifficult to gain weightLearn new habits and like new foodsUnderweight vs. anorexia nervosa
Weight-Gain Strategies
Key diet planning strategiesEnergy-dense foods Exercise