Chapter 8 Improving Nutrition, Weight Control, and Diet, Exercise, and Safety PDF

CHAPTER 8 IMPROVING NUTRITION, WEIGHT CONTROL AND DIET, EXERCISE, AND SAFETY CHAPTER OUTLINE I. Nutrition A. Components of Food 1. Chemical components of food a. carbohydrates - sources of energy. i. simple suga...

CHAPTER 8 IMPROVING NUTRITION, WEIGHT CONTROL AND DIET, EXERCISE, AND SAFETY CHAPTER OUTLINE I. Nutrition A. Components of Food 1. Chemical components of food a. carbohydrates - sources of energy. i. simple sugars - glucose and fructose ii. complex sugars -sucrose, lactose, and starch b. lipids - provide energy i. includes saturated and unsaturated fats and cholesterol ii. diet should contain 10% - 30% fat. c. proteins - involved in cell synthesis i. comprised of approx. 20 amino acids - half are essential for body functioning and found only in the diet d. vitamins - organic chemicals that regulate metabolism and body functions i. fat-soluble vitamins (A, D, E, and K) - dissolve in fats and stored in body's fatty tissue. ii. water-soluble vitamins (B and C) - are not stored in the body but are excreted in urine. e. minerals - inorganic substances important in body development and functioning. i. examples: calcium, phosphorus, potassium, sodium, iron, iodine, and zinc. 2. Fiber a. a non-nutrient component of food not used in metabolism but needed for digestion. 3. Six basic food groups a. consists of grains, fruits, vegetables, milk products, meat and fish, and Oils and Sweets. (Figure 8-1, page 202). b. contain all necessary nutrients and fiber for most people. i. taking too much of some nutrients may result in a form of poisoning. ii. pregnant women may need to adjust diets and take supplements such as iron and vitamin B 230  iii. antioxidants such as vitamins A, C, and E reduce cell damage from oxidation 4. Unprocessed foods are generally healthier than processed foods. 5. Food additives may cause allergic reactions in some or may be carcinogenic. B. What People Eat 1. Diets vary by gender and across cultural groups. a. study of 23 countries revealed that women generally eat healthier diets than men, but there were marked national differences 2. American diets have increased in consumption of sugar, animal fats, and animal proteins and decreased in fiber. 3. Diets are determined by biopsychosocial factors. a. biological influences i. preference for sweet and avoidance of bitter foods appears to be inborn. ii. fatty foods activate pleasure centers in the brain. b. food availability and exposure to certain foods via television increases liking in children. c. portion sizes and the ability to regulate or manage one’s food buying or eating are also important factors 4. Nutritional differences are reflected in the height of children around the world. C. Nutrition and Health 1. Section introduction a. public response to mass media campaigns to eat healthier i. some products from health food stores are beneficial, others have dubious worth. ii. becoming a vegetarian can range from avoiding red meats to consuming no animal products. - essential to maintain balance of protein and other nutrients. 2. Diet and atherosclerosis a. cholesterol is the dietary culprit in atherosclerosis. i. produced by our bodies with remaining coming from diet. ii. may form plaques in blood vessels depending on presence of lipoproteins. b. types of lipoproteins i. low-density lipoprotein (LDL) - a "bad" cholesterol associated with increased plague deposits. ii. high-density lipoprotein (HDL) - a "good" cholesterol that carries away LDL to be processed or removed by liver. iii. triglycerides are in most fats consumed and increase risk of heart disease iv. omega-3 fatty acids occur at high levels in fish, reduce triglycerides, and raise HDL 231  v. trans-fatty acids are in processed oils such as margarine and increase LDL c. normal levels of cholesterol i. “bad” cholesterol is most important and depends on 5 risk factors - age (over 45 for men, 55 for women) - cigarette smoking - high blood pressure - HDL cholesterol below 40 - family history of early cardiovascular disease ii. scores are total number of risk factors indicated - scores of 0-1 indicates low risk - higher scores should keep LDL level below 70 d. cholesterol levels are determined partly by heredity and lifestyle. i. smoking raises LDL, lowers HDL. ii. diets high in animal products contain high concentrations of cholesterol. e. controlling cholesterol i. cholesterol intake shouldn't exceed 300 mg. daily. ii those at higher risk should have levels assessed iii. start good eating habits in childhood. iv. use of medications such as statin drugs can reduce LDL while not affecting HDL. v. reducing cholesterol is linked to retarding/reversing development of atherosclerosis and risk for heart disease - substituting low cholesterol foods - switching to fish or poultry in place of red meats - using low cholesterol vegetable fats for cooking vi. marked reductions are associated non-illness death 3. Diet and hypertension a. hypertension is classified as blood pressure exceeding 140/90. i. 1 billion people worldwide, and 30% of American adults ii. doctor recommended lifestyle change are first methods to reduce hypertension. b. sodium intake i. body needs 500 mg of sodium a day; recommended amounts of less than 2300 mg daily. ii. reducing sodium intake reduces blood pressure in hypertensives c. caffeine intake i. increases reactivity to stress and increases blood pressure temporarily. ii. however, research indicates no link between caffeine and hypertension or heart disease 4. Diet and cancer a. studies relating certain types of cancer to low fiber and high 232  saturated fat diets are inconsistent i. it is advisable to eat little fatty meats and more fruits, vegetables, and breads and cereals b. studies on the role of vitamins A, C, and E are not definitive. i. nutritionists recommend against taking high doses. 5. Interventions to Improve Diet a. can focus on a single dietary component or an overall diet b. most effective approaches incorporate theories of health related behavior. c. interventions can include i. behavioral and educational methods ii. training and cooperation by members of the household iii. support groups iv. long-term follow-up program v. addressing the person’s food preferences II. Weight Control and Diet A. Desirable and Undesirable Weights 1. Section introduction a. criteria for judging desirability of weight i. attractiveness - being the "wrong" weight affects self-esteem, especially in girls. - greater percentage of girls than boys were dieting, reflecting gender differences in concerns with weight. ii. healthfulness - studies of mortality and morbidity rates of men and women show that those in certain weight/height ratios have far lower rates of chronic disease and longer life spans 2. Overweight and obesity a. until 1990s, overweight was evaluated by degree of departure from desirable weight charts. b. current methods include the use of the body mass index (BMI) i. overweight - BMI exceeds 25 ii. obese - BMI exceeds 30 3. Sociocultural, gender, and age differences in weight control a. prevalence of overly fat people differs by nationality, sociocultural factors, gender, and age. i. U.S. has more overweight/obese persons than other countries. - more than 2/3 of Americans ages 50 to 75 are overweight. - African American and Hispanic women are more likely to be obese than are European American 233  women. b. percentage of overweight individuals has increased substantially in the last few decades B. Becoming Overly Fat 1. Section introduction a. fat is added by consuming more calories than used by metabolism. i. stored as adipose tissue b. reasons for weight gain as we age i. accumulation of periodic weight gains ii. less physical activity and declines in metabolism 2. Biological factors in weight control a. fat tissue is less metabolically active. i. contributes to lower metabolic rate. ii. once overweight, may not still be overeating. b. malfunctioning endocrine glands explain only small percentage of obese persons. c. heredity plays a role. i. evidence from animal studies has identified defective genes that disrupt balance of energy intake and metabolism ii. twin adoption studies have consistently found genetic link iii. relationship of fatness in parents to that of children d. heredity and Set Point Theory i. Set Point Theory proposes that each person has a certain weight the body strives to maintain through hypothalamic functions. ii. hypothalamus may affect weight by - affecting amounts of enzymes that contribute to functioning of fat cells. - regulating levels of insulin; hyperinsulinemia is a condition of having high serum levels of insulin. iii. set point activity also affected by number of fat cells that develop. - as children gain weight, they do so by adding fat cells - the number of fat cells can increase, but not decrease - when persons who have fat-cell hyperplasia attempt to diet, body reacts as if going through food deprivation and energy stores of fat are maintained more efficiently. - important reason why diet and exercise in children is critical. 3. Psychosocial factors in weight control a. psychosocial factors involved in weight control include emotions, stress, and lifestyles. 234  b. restrained eaters are prone to overeating when experiencing certain emotions c. depression puts an individual at risk for binge eating i. binge eating occurs when a person eats a large amount within a short period of time ii. frequent binge eating is a common feature of obesity d. lifestyle patterns such as alcohol use and watching television can contribute to weight gain e. obese individuals are more sensitive to external food-related cues f. obese and restrained eaters are less sensitive than unrestrained eaters to the amount of fat in the food they consume i. unrestrained eaters adjust their intake of the food to compensate 4. Overweight and health a. normal and overweight people tend to rate their health the same. b. factors to consider in measuring health of normal v. overweight people. i. degree of overweight - greater the severity of obesity, greater the risk of developing and dying from hypertension, CHD, diabetes, stroke, and cancer. - the BMI of an overweight person is related to decreasing lifespan, and increased medical costs ii. level of fitness - people who are heavy but physically active and fit have lower mortality for CHD and diabetes. ii. distribution of weight - ratio of waist to hip girth is associated with hypertension, diabetes, CHD, and mortality. 5. Preventing overweight a. preventing obesity needs to start in childhood i. childhood obesity continues into adulthood. ii. developing excess fat cells as a child makes weight problems likely. iii. over half of parents of overweight children claim their child is at the right weight b. special attention to improving diets and physical activity in children can be done in schools. i. especially important for children who are already overweight or have family history of obesity. c. ways for parents to help their children i. encouraging exercise and restricting TV watching ii. not using unhealthful food rewards iii. not buying high-cholesterol or sugary foods iv. using healthful foods as desserts v. having children eat healthful breakfast and no snacks at 235  night vi. monitoring child's BMI C. Dieting and Treatments to Lose Weight 1. Section introduction a. millions of people are dieting due to concerns for health, unattractiveness, and stigma. i. in the U.S. fatness is considered unattractive, especially for females ii. many blame heavy individuals for their condition b. best approach to weight loss i. only 1/3 follow appropriate guidelines for losing weight. ii. losing weight gradually and making permanent lifestyle changes. iii. individuals are most likely to succeed at dieting if they have a high degree of self-efficacy and constructive social support iv. most people can lose weight on their own but others need help from weight loss programs. 2. Commercial and ''fad diet'' plans a. "miracle diets" generally require some unique dietary regimen. i. may be nutritionally unsound or produce unpleasant/unhealthy side effects. ii. examples: Scarsdale diet, Beverly Hills diet, Atkins diet, low-calorie liquids. iii. little empirical evidence for success claims. b. fad diets aren't a good substitute for exercise and moderate, balanced meals. 3. Exercise a. benefits of exercise i. increases metabolism ii. focuses on reduction of body fat iii. exercise plus dieting leads to greater weight loss than dieting alone. iv. aids in maintaining weight loss 4. Behavioral and cognitive methods a. conclusions regarding usefulness of behavioral methods in weight control i. behavioral techniques are helpful, but not for all patients. ii. behavioral programs have low drop-out rates. iii. about 10% of original weight is lost in the first 4 months. iv. more effective than other approaches with exception of medical treatments. v. on average individuals who complete a program gain much of it back in the first year, but many maintain loss b. common behavioral techniques used in weight loss programs i. nutrition and exercise counseling 236  ii. self monitoring iii. stimulus control iv. altering the act of eating v. behavioral contracting c. using rewards for not engaging in sedentary activities d. family-based behavioral programs help obese children and their parents lose weight together. e. cognitive methods include: i. motivational interviewing increases personal commitment and self-efficacy ii. problem-solving training - learning strategies for dealing with every day difficulties encountered when trying to stick to a diet. 5. Self-help and worksite weight-loss programs a. self-help groups i. example - Weight Watchers, a self-help group that incorporates behavioral techniques such as self-monitoring along with nutritional information and group meetings into program ii. little research has been done on success of programs - one study found moderate weight loss for those who complete a program. - attrition rates are high; in one program, over 70% dropped out in the first 12 weeks. b. worksite-weight-loss programs i. generally use behavioral techniques but not particularly successful - high dropout rates and little weight loss most likely due to low motivation. ii. increasing motivation may occur by - gearing program to stage of readiness - providing incentives - e.g., weight loss competitions 6. Medically supervised approaches a. medications i. sibutramine – suppresses appetite ii. orlistat reduces conversion of calories to fat but produces only small weight loss. iii. combining medication and behavioral treatments is better than either alone iv. because of side effects, drugs recommended usually only for obese persons. b. very low calorie diets i. diets with fewer than 800 calories per day, usually for the very obese ii. not recommended for patients with heart disease. c. bariatric surgery involves changing the structure of the stomach 237  reduce appetite and consumption d. liposuction removes adipose tissue from the body; this is considered cosmetic as apposed to a weight reducing method d. choosing appropriate methods requires matching methods to person's weight problems and characteristics. 7. Relapse after weight loss a. reasons for relapse often involve food cues, negative emotions, and boredom b. relapse can be limited by follow-up treatment programs including frequent therapist contact and social support. c. methods for effective weight loss i. use behavioral techniques. ii. reduce calorie and fat content of diet. iii. continue to exercise after weight has been lost. iv. avoid situations that prompt lapses and reward good behavior. v. invoke social support from family and friends. D. Anorexia and Bulimia 1. Section introduction a. anorexia nervosa i. maintain weight 15% below normal weight, fear weight gain, distorted body image, and absence of menstruation. ii. death can occur due to low blood pressure, heart damage, or cardiac arrhythmias. iii. more common in dancers, models, and athletes. b. bulimia nervosa i. recurrent binge eating followed by purging via vomiting or laxative use. ii. medical problems include inflammation of digestive tract and cardiac problems. iii. individuals are aware that their eating pattern is abnormal, fearful of losing control of eating, and are self- critical following an episode. c. current prevalence data is likely to be an underestimate i. population prevalence approximately 0.5-1.0% for anorexia and 1-2% for bulimia in Western cultures ii. more than 90% of those diagnosed are female 2. Why people become anorexic and bulimic a. genetic and physiological factors i. twin studies find anorexia and bulimia are more likely to appear in both twins. ii. functioning of neuroendocrine and neurotransmitter processes may be abnormal. b. cultural factors i. changes in the "ideal figure" and increased pressure to be slim. 238  ii. individuals with anorexia and bulimia often start dieting normally as teens and then adopt extreme practices. c. cognitive factors i. individuals with anorexia and bulimia overestimate or distort body size. d. personality factors i. high perfectionism 3. Treatments for anorexia and bulimia a. first priority in treatment is restoring normal weight. b. relapse rates for anorexics tend to be fairly high. c. treatment includes cognitive methods to address irrational thinking. d. most successful treatments for bulimia include cognitive and behavioral methods plus antidepressant drugs III. Exercise A. The Health Effects of Exercise 1. Types and amounts of healthful exercise a. isotonic exercise--builds strength and endurance, exert muscle force in one direction moving a heavy object b. isometric exercise--builds strength, rather than endurance, exert force against an immovable object c. isokinetic exercise--builds strength and endurance by exerting muscle force in more than one direction d. aerobic exercise--physical exercise that requires high levels of oxygen over an extended period of minutes 2. Psychosocial benefits of exercise a. reduces stress and anxiety. b. work performance and attitude improve. c. enhances self-concept. 3. Physical effects of exercise a. increased production of endorphins. b. slows the decline in fitness with age. c. increases longevity. c. decreases risk of coronary heart disease, lowers blood pressure, and reduces the risk of some forms of cancer d. risks include accidents, injuries, heat exhaustion, or cardiac arrest, and potential use of anabolic steroids. 4. Health liabilities to exercise a. Injuries, accidents. b. Sudden cardiac death. c. Use of anabolic steroids. B. Who Gets Enough Exercise, Who Does Not, And Why? 1. Section introduction a. around the world most people have lifestyles that promote regular, vigorous, sustained activity naturally. 239  b. peoples in industrialized countries tend to have more sedentary lifestyles. i. adults in these cultures choose not to exercise. 2. Gender, age, and sociocultural differences in exercise a. those who exercise tend to be the young, upper SES, educated, with a history of exercise. b. are more likely to be male and white c. the elderly seem to be limited more by misconceptions about appropriate activity than physiological limitations 3. Reasons for not exercising a. common reasons given for not exercising i. lack of time ii. no convenient place iii. too much stress in their lives iv. social influences and beliefs b. positive influences on exercising i. high self-efficacy regarding ability to exercise. ii. higher perception of vulnerability to illness. iii. enjoyment of the exercise C. Promoting Exercise Behavior 1. Strategies to promote exercise a. pre-assessment i. examining purposes for exercising and assessing health status. b. exercise selection i. tailoring exercises to meet health needs of person and interests. c. exercise conditions i. determining when and where the person will exercise ii. obtaining necessary equipment. iii. setting a fixed or flexible schedule. d. goals i. determining specific sequence of outcomes in a behavioral contract. e. consequences i. determining appropriate rewards for exercise. f. social influence i. exercising with partners ii. enlisting support and encouragement from family and friends. g. record keeping i. charting progress on weight goals and exercise performance. 2. Other factors in promoting exercise behavior a. rewards needed for increasing exercise and decreasing sedentary behaviors. 240  b. physicians can increase activity by giving verbal and written advice on specific exercise goals and behaviors. c. sedentary people are more likely to stick with a program of high frequency exercise rather than high intensity c. telephone contacts to assess progress and provide advice are successful. d. need to assess readiness to start and stick to an exercise program. IV. Safety A. Accidents 1. 3.9 million people die from unintentional injuries worldwide each year a. Nearly 121,000 individuals in the U.S. die each year from unintentional injuries. 2. Poisonings and traffic accidents are the most frequent a. driver training classes do little to reduce accidents. b. automobile and highway design and legal restrictions can decrease accidents. i. examples: extra brake light, laws against drivers using cell phones, raising legal driving age. c. use of protective equipment such as helmets, seat belts, and protective car seats for children has risen sharply. i. laws requiring use are probably helpful but not sufficient. B. Environmental Hazards 1. Exposure to ultraviolet rays may lead to skin cancer which can be prevented with sun screen. a. tanned appearance interpreted as "healthy" and "fashionable". b. interventions using gain-framed messages produce more sun- screen use than do those with loss-frame messages. 2. Potential household and workplace hazards a. lead poisoning b. radon c. asbestos d. radiation 3. "Right to Know" laws a. some states require employers to inform and train employees on use of hazardous materials. b. community agencies may be required to provide information and supportive measures to community members in presence of an environmental hazard. 4. Considerations regarding chemicals/gasses in the environment a. not all chemicals or gasses are harmful. b. exposure to toxic or carcinogenic substances poses little risk when exposure is infrequent and the dosage is small. c. some harmful substances have benefits that outweigh their dangers. 241