Obesity and Eating Disorders Chapter 14

Obesity and Eating Disorders Prevalence of obesity (BMI ≥30) in American adults aged 20 and older has almost tripled from 13% to 31.4% over the last 40 years One of the most common causes of preventable death A far less common weight issue is disordered eating manifested as anorexia nervosa or bulimia Historically the study of obesity and eating disorders has been separate Commonalities between them

Obesity Overweight is defined as having a BMI ≥25 Related to an excessive body weight, not necessarily excessive body fat Obesity is defined as having a BMI ≥30 Generally assumed to be related to an excessive amount of body fat

Obesity (cont’d) Causes of obesity Occurs when people eat more calories than they expend over time Why it occurs is not fully understood “Set point” theory of weight control Some people are able to burn hundreds of extra calories in the activities of daily living to help control weight Likely that a combination of genetic and environmental factors is involved

Obesity (cont’d) Genetics More than 300 genes have been linked to obesity About 30% to 40% of the variance in BMI is attributed to genetics About 60% to 70% is attributable to environment Genetics are involved in: How likely a person is to gain or lose weight Where body fat is distributed Response to overeating

Obesity (cont’d) Environment Rise in obesity without change in gene pool Root cause is lifestyle and environment, not biology Environmental influences include: Abundance of palatable, low-cost, high-calorie– density foods that are readily available in prepackaged forms and in fast food restaurants Increasing consumption of soft drinks and snacks Great proportion of food expenditures spent on food away from home

Obesity (cont’d) Environment (cont’d) Influences include: Growing portion size of restaurant meals Low levels of physical activity Increases in television watching Widespread use of electronic devices in the home, such as computers and video games All lead to sedentary lifestyle

Obesity (cont’d) Environment (cont’d) Gene–environment interaction In people with a genetic predisposition to obesity, the severity of the disease is largely determined by lifestyle and environmental conditions Complications of obesity Most common complications of obesity include: Insulin resistance, type 2 diabetes, hypertension, dyslipidemia, cardiovascular disease, stroke, gallstones and cholecystitis, sleep apnea, respiratory dysfunction, and increased incidence of certain cancers

Obesity (cont’d) Complications of obesity (cont’d) Increases the risk of complications during and after surgery Obesity is considered to be a major contributor to preventable deaths in the United States Obesity presents psychological and social disadvantages Negative social consequences

Question Is the following statement true or false? Respiratory dysfunction is one of the most common complications of obesity.

Answer True. Rationale: The most common complications of obesity are insulin resistance, type 2 diabetes, hypertension, dyslipidemia, cardiovascular disease, stroke, gallstones and cholecystitis, sleep apnea, respiratory dysfunction, and increased incidence of certain cancers.

Obesity (cont’d) Goals of treatment Ideally, treatment would “cure” overweight and obesity In reality, this ideal is seldom achieved A modest weight loss of 5% to 10% of initial body weight is associated with significant improvements in blood pressure, cholesterol and plasma lipid levels, and blood glucose levels

Obesity (cont’d) Goals of treatment (cont’d) Modest weight loss: Is more attainable Is easier to maintain over the long term Sets the stage for subsequent weight loss

Obesity (cont’d) Evaluating motivation to lose weight Objectively identifying who may benefit from weight loss Assessing the client’s level of motivation is crucial Imposing treatment on an unmotivated or unwilling client may preclude subsequent attempts at weight loss

Obesity (cont’d) Evaluating motivation to lose weight (cont’d) Treatment approaches A lifestyle approach is the basis of treatment for all people whose BMI is ≥30 Includes diet modification Exercise Behavior modification Pharmacotherapy and surgery may be used in conjunction with lifestyle interventions, based on the individual’s BMI and the presence of comorbidities

Obesity (cont’d) Treatment approaches (cont’d) Diet modification Cornerstone of most weight-loss programs Fewer calories Macronutrient composition Micronutrient composition Nutrition education Promoting dietary adherence

Obesity (cont’d) Treatment approaches (cont’d) Physical activity Benefits of exercise are numerous Favorably impacts metabolic rate Dietary Guidelines recommend adults engage in approximately 60 minutes of moderate- to vigorous-intensity activity on most days of the week to prevent weight gain

Obesity (cont’d) Physical activity (cont’d) 60 to 90 minutes of daily moderate-intensity physical activity are recommended to sustain weight loss Promoting exercise adherence: Seems to increase with less structure Strategies that may promote exercise adherence Exercise at home Exercise in multiple short bouts (10 minutes each), Adopt a more active lifestyle

Obesity (cont’d) Behavior modification Focuses on changing the client’s eating and exercise behaviors Key behavior modification strategies: Self-monitoring Goal setting Stimulus control Problem solving Cognitive restructuring Relapse prevention

Obesity (cont’d) Pharmacotherapy Recommended for: People with a BMI ≥30 People with a BMI ≥27 with comorbid conditions People with waist circumference greater than 35 inches (women) and 40 inches (men) are also candidates for pharmacotherapy if comorbidities are present

Obesity (cont’d) Pharmacotherapy (cont’d) 2 drugs approved by the FDA for long-term use have been shown effective in helping promote and maintain weight loss Alli is the only over-the-counter drug to gain FDA approval for the treatment of obesity Expected weight loss is modest (perhaps half of the usual 6 pounds/1 year credited to orlistat) Phentermine Approved for short-term use (≤3 months)

Obesity (cont’d) Pharmacotherapy (cont’d) Drugs are central nervous system stimulants Tolerance may develop after only a few weeks Risk of abuse Common side effects: Increased heart rate and blood pressure, dry mouth, agitation, insomnia, nausea, diarrhea, and constipation

Question One of the treatments for obesity is behavior modification. Which of the following is an aspect of behavior modification? a. Stimulus recognition b. Professional monitoring c. Cognitive restructuring d. Problem identification

Answer c. Cognitive restructuring Rationale: Key behavior modification strategies are self-monitoring, goal setting, stimulus control, problem solving, cognitive restructuring, and relapse prevention.

Obesity (cont’d) Surgery Most effective treatment for severe obesity Appropriate for clients whose BMI is 35 to 39.9 who have major comorbidities Works by: Restricting the stomach’s capacity Creating malabsorption of nutrients and calories A combination of both

Obesity (cont’d) Surgery (cont’d) Laparoscopic adjustable gastric banding (LAGB) An inflatable band encircles the uppermost stomach and is buckled Small pouch of approximately 15- to 30-mL capacity is created with a limited outlet between the pouch and the main section of the stomach Outlet diameter can be adjusted by inflating or deflating a small bladder inside the “belt” through a small subcutaneous reservoir

Obesity (cont’d) Laparoscopic adjustable gastric banding (LAGB) (cont’d) Size of the outlet can be repeatedly changed as needed Mortality rate for gastric banding is the lowest of all bariatric procedures Successful weight loss after LAGB requires frequent follow-up and band adjustments

Obesity (cont’d) Roux-en-Y gastric bypass (RYBG) Combines gastric restriction to limit food intake with the construction of bypasses of the duodenum and the first portion of the jejunum Creates malabsorption of nutrients “Dumping syndrome” Superior to gastric resection in both promoting and maintaining significant weight loss Major complication with RYBG is anastomotic leak

Obesity (cont’d) Post-surgical diet Progression begins with small quantities of sugar-free clear liquids Advances as tolerated to full liquids, followed by pureed foods and then a regular diet within 5 to 6 weeks after surgery Nutrition therapy guidelines

Obesity (cont’d) Weight maintenance after loss Keeping weight off is even harder than losing it Diets that lead to weight loss are not necessarily effective for maintaining weight loss National Weight Control Registry (NWCR) Single best predictor of who will be successful at maintaining weight loss is how long someone has kept their weight off

Obesity (cont’d) Obesity prevention Small changes in diet and exercise that total a mere 100 calories/day may be enough to prevent obesity in most of the population 1 ounce of cheddar cheese/day for 1 year = 10 pound weight gain

Eating Disorders: Anorexia Nervosa (AN), Bulimia Nervosa (BN), and Eating Disorders Not Otherwise Specified (EDNOS) Defined psychiatric illnesses that can have a profound impact on nutritional status and health Generally characterized by abnormal eating patterns and distorted perceptions of food and body weight Continuum of disordered eating

Eating Disorders: Anorexia Nervosa (AN), Bulimia Nervosa (BN), and Eating Disorders Not Otherwise Specified (EDNOS) (cont’d) Etiology Considered to be multifactorial in origin Risk factors: Dieting, early childhood eating and GI problems, increased concern about weight and size, negative self-evaluation, and sexual abuse

Eating Disorders: Anorexia Nervosa (AN), Bulimia Nervosa (BN), and Eating Disorders Not Otherwise Specified (EDNOS) (cont’d) Etiology (cont’d) Precipitating factors Onset of puberty, parents’ divorce, death of a family member, and ridicule of being or becoming fat People with eating disorders often suffer from: Depression, anxiety, substance abuse, or body dysmorphic disorder

Eating Disorders: Anorexia Nervosa (AN), Bulimia Nervosa (BN), and Eating Disorders Not Otherwise Specified (EDNOS) (cont’d) Etiology (cont’d) Treatment plans are highly individualized Antidepressant drugs effectively reduce the frequency of problematic eating behaviors Most eating disorders are treated on an outpatient basis Nutritional intervention seeks to reestablish and maintain normal eating behaviors

Question What is a risk factor for eating disorders? a. GI problems b. Adolescent eating problems c. Binge eating d. Depression

Answer GI problems Rationale: Risk factors that precede the diagnosis of an eating disorder include dieting, early childhood eating and GI problems, increased concern about weight and size, negative self-evaluation, and sexual abuse (ADA, 2006).

Nutrition Therapy for Anorexia Step-by-step goals of nutrition therapy: To prevent further weight loss To gradually reestablish normal eating behaviors To gradually increase weight To maintain agreed-upon weight goal Half of those who receive care are expected to recover Overall mortality rate is 9.8%

Nutrition Therapy for Anorexia (cont’d) Involving the client in formulating individualized goals and plans promotes compliance Large amounts of food may not be well tolerated

Nutrition Therapy for Bulimia Nervosa People with BN tend to have fewer serious medical complications than people with AN because their undernutrition is less severe Nutritional counseling focuses on identifying and correcting food misinformation and fears Structured and relatively inflexible to promote the client’s sense of control Initial meal plan provides adequate calories for weight maintenance

Nutrition Therapy for Bulimia Nervosa (cont’d) Adequate fat is provided to help delay gastric emptying and contribute to satiety Calories are gradually increased as needed

Eating Disorders Not Otherwise Specified At least as common as AN and BN This group represents: Subacute cases of AN or BN Binge eating disorder