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CHS 412 Lecture 2 Health Education to prevent and control Obesity and its danger Dr. Ebtisam Fetohy Objectives of the lecture At the lecture the students will be able to: 1-Define Obesity 2-List different methods for measurements of obesity and overweight 3-Classify obesity 4-Identify advantages and disadvantages of BMI to assess health risks 5-List Causes of obesity 6-List diseases associated with obesity Obesity as a public health problem The rapid rise in the prevalence of obesity in both rich and poor countries in recent years has been described as an epidemic. • At the global level, excess body weight is the sixth most important risk factor for ill health. • Many adverse health outcomes are strongly associated with obesity. How is obesity measured? It is defined as the excessive accumulation of body fat. -There are a number of ways to measure body fat: Measurements that are simple, cheap and appropriate for routine use include: • Waist circumference • Hip circumference • Waist-to-hip circumference ratio • Indices derived from weight and height, e.g. body mass index • skin fold thickness using calipers (e.g. triceps, scapular) How is obesity measured? • Measurements of body fat that are expensive and require special equipment and highly trained personnel include: Underwater weighing Bioelectrical impedance المعاوقة Computerized topography Classification of obesity (1) – ‘apples’ and ‘pears’: 1. The apple shape: also called “android”, “abdominal” or “central” obesity • People with high waist-to-hip ratios are "apples", • Their body fat is distributed mainly on the upper trunk, the chest and abdomen giving the typical ‘apple shape’ • Individuals are mostly male • A waist-to-hip ratio >1.0 for men and >0.8 for women indicates an increased risk of cardiovascular disease and diabetes mellitus Classification of obesity (1) – ‘apples’ and ‘pears’: 2. The pear shape: also called “gynaeoid” or “peripheral” obesity • People with lower waist to hip ratios are "pears“ – • Their body fat is distributed mainly on the lower trunk, the hips and thighs giving the typical ‘pear shape’. • Individuals are mostly female. • Associated health risks are minimal if any. Obesity can be classified into two groups on the basis of body fat distribution and the waist-to-hip circumference ratio. -This simple classification is easily understood by the public and also predicts the risk of obesity-related health problems. Classification of obesity (2) – body mass index (BMI): • Classification of obesity (2) – body mass index (BMI) BMI = weight in kilograms - kg/m2square of height in meters Over weight definition 1 Note: Although overweight is identified by a BMI of ≥ 25.0 kg/m2, the risks of obesity-associated diseases, such as: • Diabetes, • Hypertension and • Dyslipidaemia, increase from a BMI of about 21.0 kg/m2. NIH: A weight and height chart is a useful clinical tool to determine a person’s BMI Advantages of using BMI to classify obesity • It is low-cost and • Easy to use for health professionals for assessing individuals, it is commonly used to determine desirable body weights and • It allows people to compare their own weight status to that of the general population • It correlates well with the amount of body fat as measured by more complex techniques • It predicts dangers associated with obesity; as BMI increases the risk for diseases increases • It is a useful screening tool to use at the population level and, • Because it is universally accepted, BMI reference data is available for many different populations Disadvantages of BMI BMI: Which of these men is at risk of ill health and why? (a) (b) These men have the same height, weight and BMI, but have different percent body fat BMI calculated as follows: BMI = 28.4 kg/ m2. Although BMI is equally high in both men, it is not known: (a) It is due to lean body mass or (b) It is due to body fat. -This shows that, used alone, a high BMI is not diagnostic of obesity. BMI also varies with age and sex in those <18 years. These are some of the disadvantages of using BMI to assess health risks. Questions Put “true” or “false”: • Obesity is the excessive accumulation of body fat • Body mass index (BMI) is the most universally accepted index of obesity • A woman with a BMI of 46.0 is overweight • To calculate the BMI of an individual, we need the weight, height and body fat distribution • A man with weight 76 kg and height 1.55 m is obese. Question 2: A 25 year old male athlete weighs 87.3kg and has a height of 1.75m: A. Calculate his BMI How would you classify his BMI ? B. Is the classification of obesity based on BMI reliable for this man and, if not, why? The global burden of obesity • • • • The USA has the highest obesity rate in the world. IN American adults, 50m are obese (BMI >30.0) and 6m have class III obesity (BMI >40.0). Obesity in adolescents has increased from 5% in 1966 1970 to 14% in 1999. Obesity in adults on the increase - worldwide • Dramatic increases in obesity in recent years is not confined to the USA. • Obesity in children living in poorer countries: Obesity in children living in poorer countries Africa & Middle East: 4 year olds • Latin America and Caribbean: 4-10 year olds • Prevalence of overweight in 10-year old children in selected countries The burden of obesity – costly, deadly…: • The financial burden of obesity: WHO data show that obesity accounts for 5-10% of the total health care budget in several developed countries • This is probably a low estimate as not all of the cost of management of obesity and its related problems can be calculated • In 2000, the U.S. spent $117 billion on obesity (9% of the national total health budget) The burden of obesity – costly, deadly…: • The morbidity and mortality burden of obesity: Overall, about 2.5 millions deaths are attributed to overweight/obesity worldwide In the UK, about 30,000 deaths are attributable to obesity. • Ten times this figure occurs in the US where obesity is the second greatest preventable cause of death following smoking • Nearly 70% of cases of cardiovascular disease are associated with obesity • Obesity predisposes to an overall reduction of quality of life and premature death from diet related, chronic noncommunicable diseases People who are obese or overweight also have a lower life expectancy • A 40-year-old nonsmoking male who is overweight will lose 3.1 years of life expectancy; one who is obese will lose 5.8 years. • A 40-year-old overweight nonsmoking female will lose 3.3 years of life expectancy; one who is obese will lose 7.1 years. Questions 3: Write “T” or “F”: 1. Obesity is a worldwide public health problem 2. Obesity is not a major public health problem in developing nations 3. The highest rate of obesity is found in the U.S.A 4. Obesity related problems account for less than 5% of healthcare budget in developed countries 5. Obesity leads to premature death from diet related chronic communicable diseases. Calories in and calories out – the imbalance • • • • 1. 2. 3. 4. The energy value of food can be expressed in calories. Obesity occurs when a person consumes more calories than his/her body needs. Excess calories are stored as fat and lead to weight increase. For e.g., consuming 3,500 calories more than the body needs results in a gain of 0.45kg of fat. The factors which affect the balance between calories in and calories out differ from one person to another. Obesity is believed to result from a complex interplay of the following factors: Genetic factors Socio-economic (lifestyle and diet) Cultural factors Psychological and medical factors Genetic factors: • We know that obesity tends to run in families, suggesting a genetic cause. • Although, families also share diet and lifestyle, both of which contribute to obesity, research has shown that genetic factors account for as much 80% of the link between heredity and obesity. • Studies in adoptees المتبنونand twins strongly support this link: Adults who were adopted as children have weights closer to their biological parents than to their adoptive parents • Monozygotic (identical) twins show a much stronger correlation in body weight than dizygotic (nonidentical) twins. Socio-economic factors and lifestyle Diet Apart from our genes, environmental factors also contribute to the recent surge زيادة مفاجئةin obesity. The following changes in diets across the world play a major role: • Increase in consumption of energy dense foods – containing animal fats • Decrease consumption of complex carbohydrates and fibre - coarse grains, fruits • Increase intake of salt and alcohol Socio-economic factors and lifestyle In recent years, societies of the western world have enjoyed an over abundance of food – • So people feast تمتعon larger portions at low prices. • As this “affluence” اليسرcreeps into the urban centres of the developing world, we are beginning to see a rise in obesity. • The growth of the fast food industry has made an abundance of high fat, inexpensive meals widely available, resulting in a shift in stable المستقرةfoods from low quality staples (corn) to high quality refined staples (processed rice, wheat). Cultural factors (1): • The cultural practice of placing young women in ‘fattening rooms’ for months before marriage or after childbirth. In fattening تسمينrooms, the daily routine was to: 1. Sleep , 2. Eat and 3. Grow fat. The women spent their time resting like beached whales and gorging التهامon a high-fat, highcalorie diets. This practice has greatly reduced in recent years in south-eastern parts of Nigeria. • In certain cultures of the world ‘big is beautiful’. Obesity was a sign of wealth and well-being in the past and still is in many parts of Africa. Cultural factors(2): • In contrast to many Western cultures where thin is, in many culture-conscious people in these parts hailed رحبت, a woman's rotundity تكورas a sign of good health, prosperity ازدهارand allure اغراء. • The Japanese sumo wrestlers مصارعونare well known obese individuals. They achieve their big size from: 1. An elaborate متقنrice- based diet, 2. Fat-rich stew حساءand 3. Lots of sleep. Psychological and medical factors:/1 1. Psychological factors are known to influence eating habits. Many people eat in response to negative emotions, such as anger, sadness or boredom . 2. Metabolic and organic factors including drug therapies have been associated with obesity as metabolic rate slows down, the tendency to gain weight increases. Slow metabolic rate is found with reduced physical activity, advancing age, and in females compared to males Psychological and medical factors:/ 2 3. Certain medical conditions are associated with obesity: depression, hypothyroidism, pituitary tumors, cerebral diseases including infections, hydrocephalus, as well as certain chromosomal anomalies – Down syndrome. 4. Drugs that can cause weight gain include: corticosteroids, anti-depressant drugs, antipsychotics, oral contraceptive and progestagenic compounds, hypoglycemic agents, insulin, antihistamines, Question 5: Which of the following factors will increase the risk of obesity in an individual? Write “T” or “F”.: A. Physical inactivity B. Consumption of fast foods C. Psychological depression D. Normal sized parents E. Hyperthyroidism Question 6: • Several factors play a role in the pathogenesis of obesity. What risk factors match the following pictures?: a)? c)? b)?. Obesity is a disease. • nd /2 part Associations with obesity are protean متقلبة. Medical associations of obesity: 1. 2. 3. 4. 5. 6. 7. 8. Hypertension and Type II diabetes Coronary artery disease, and Stroke, Cancers and Reproductive abnormalities Psychological complications including eating disorders, Respiratory and other complications. Effects of obesity Obesity - a known risk factor for several lifethreatening medical conditions (1) Diabetes Mellitus (DM) : • The relation between obesity and type II diabetes (non-insulin dependent diabetes) has been established since the 1970s excess. Fat deposits in obesity is associated with: 1. Insulin resistance, 2. Glucose intolerance and 3. Premature type II diabetes. (1) Diabetes Mellitus (DM):/2 • 90% of patients with type II diabetes have BMI higher than 23kg/m2 • The risk of type II DM is greatly increased where there is: A.A history of early weight gain (childhood obesity), B.Android obesity (The apple shape), C.Positive family history of DM, and D.Maternal history of gestational DM. Obesity - a known risk factor for several lifethreatening medical conditions (2) Coronary artery disease and stroke: • The effect of obesity on cardiac function is thought to be due to a combination of: 1. Hypertension, 2. Diabetes mellitus, 3. Dyslipidaemia and 4. Increased fat mass • The risk increases as BMI values exceed 21.0 kg/m2. Studies show that heart failure in 14% women and 11% men is due to obesity (3)Cancers: • 1. 2. 3. 4. 5. The risk for cancers is more among the obese than the non-obese population estimates indicate that overweight and inactivity account for a quarter to a third of cancers of the: Breast, Colon, Endometrium, Kidney and Esophagus (4)Psychological features of obesity: • In US women obesity increases the risk of being diagnosed with: 1. 2. 3. 4. 5. Major depression by 37% Low self esteem, Anxiety, قلق Depression and Obsessive االستحواذيbehaviors are common among obese individuals especially women Obesity and depression are linked closely with two eating disorders: A. Night eating syndrome and B. Binge افراطeating disorder (including bulimia النهم nervosa). These need early recognition and early psychotherapy Other effects of obesity (2): 1. Obesity has serious deleterious effects on quality of life. 2. 3. 4. There is the social stigma associated with obesity, 20% of obese people are less likely to marry than their thinner counterparts The annual household income of obese people is nearly $7,000 less than that of thinner people An obese person is 10% more likely to live a life of poverty 5. With obesity there is: Restricted activity, Exercise intolerance, Pain, Worry, Low self esteem, and Depression Question 7 Which of the following are recognized associations of obesity. Write “T” or “F”: a) Hypertension b) Type 1 diabetes c) Osteoarthritis d) Ovarian cancers e) Coronary heart disease What is childhood obesity ?/1 Defining childhood obesity : Obesity in childhood has reached epidemic levels. • In the US, it is the most common nutritional disorder in children. • Developing countries are also affected as the prevalence rises among children of urban dwellers who emulate يحاكيthe ‘affluent western lifestyle’ What is childhood obesity ?/2 As in adults, the WHO uses the body mass index (BMI) as the standard definition of obesity in children. BMI is calculated with the same formula for children and adults, but the results are interpreted differently: BMI for children, also referred to as BMI-for-age, is gender and age specific BMI changes dramatically with age in children as body fat changes with growth, and between girls and boys with maturity BMI-for-age, gender specific growth charts used for children and teens 2 – 20 years of age. Defining childhood obesity: • BMI-for-Age is used for children and teens because of their rate of growth and development. • It is a useful tool because: A. BMI-for-age in children and adolescents compares well to laboratory measures of body fat B. BMI-for-age can be used to track تعقيبbody size throughout life In children, obesity is defined as a BMI greater than the 95th percentile for age o while overweight is a BMI greater than the 85th percentile for age till the 95th percentile for age Risk factors for childhood obesity/1: 1. 2. 3. 4. 5. Obesity in one or both parents Infants of diabetic mothers Children from single parent families Families with fewer children and Higher birth weight Risk factors for childhood obesity/2: 6. Rapid growth during infancy are associated with an increased prevalence of obesity 7. Formula feeding during infancy (Breast feeding in women who didn't smoke during pregnancy [but not in women who smoked during pregnancy] was significantly associated with a reduced risk of obesity) Risk factors for childhood obesity • Sedentary lifestyle – increase TV viewing, computer games, car rides, including a reduction in number of mandatory physical education classes in schools especially in the US • Increase consumption of sugar sweetened drinks, soda, snacks, energy dense fast food in large portions. The relationship between childhood and adult obesity • Born in the 60’s with a birth weight of 2.7kg (normal weight), she quickly became plump in infancy. Neither parent was overweight (father 72.6kg and1.72m; mother 50.8kg and 1.52m) From the age of 7, she was significantly heavier than her peers. In her early teens, she “weighed 88.9kg” and was advised by her pediatrician to join a slimming club. The weight gain persisted till adulthood. She is currently on nine different medications for obesity related problems • bridesmaid وصفat wedding-Married at age 40 weight 178 kg, Height - 1.65m, BMI = 66 kg/m2 The relationship between childhood and adult obesity • 1. 2. 3. 4. Now that you have read this story, list 5 obesity-associated problems that may occur in this woman. Mrs. S. actually developed: hypertension type II diabetes hypothyroidism menorrhagia 5. recurrent cellulitis Other possible problems include : 6. osteoarthritis 7. stroke 8. metabolic syndrome 9. coronary heart disease 10.menstrual disorders 11.psychological disorders 12.cancers – ovarian, endometrial, breast, cervical, prostate Question 8: • The following are statements about childhood obesity. Write “T” or “F”.: a) Obesity is not a problem in children b) BMI-for-age is used for children and teens because of their rate of growth and development c) The use of BMI to define obesity doesn’t depend on gender d) BMI-for-age in children and adolescents compares well to laboratory measures of body fat e) The longer a child remains obese beyond age 3 years, the more likely that the obesity will persist into adulthood Management of obesity/1: Effective management of obesity requires long-term strategies and an integrated, multi-disciplinary approach that includes: 1. Community-based support for behavioral modification including: diet and exercise. 2. Research over the last decade indicates that a 5-10% reduction in body weight is sufficient to significantly improve medical conditions associated with obesity, such as: Hypertension, Diabetes mellitus, and Elevated cholesterol levels. Management of obesity/2: Currently there is lack of evidence of effective programmes for integrated management of obesity. But the following management options for the management of obesity exist: A. Dietary modification B. Behavioral modification C. Physical activity D. Pharmacotherapy E. Surgery Management of obesity/3: As always, “prevention is better than cure”. 1. Recently the UK government has set a target to halt يوقف the rise in obesity in children aged ≤11 by 2020. 2. Strategies for the prevention of childhood and adult obesity may need to address factors during or before infancy that are related to infant growth. Management options (1): • 1. 2. 3. 4. Dietary modification the most common and conservative treatment for obesity utilizes: A nutritionally balanced diet, Low calorie diet, Diet must include more fruits and vegetables, nuts, whole grains and exclude fatty and sugary foods Weight-loss programs recommend diets consisting of 1,200 to 1,500 calories per day, The calories usually in the following proportions: A. B. C. 60 % carbohydrate, 30 % fat, and 10 % protein. Individuals must be carefully screened and medically supervised while on the diet (the degree of weight loss being dependent on individuals ability to adhere to dietary recommendations) Studies have shown that meal replacements بدائلare often more effective than very low calories diets, resulting in an increase in the amount of initial weight loss and enabling dieters to maintain their weight loss Management options (2) Pharmacotherapy: • It is recommended that anti-obesity drugs be used only in: 1. Individuals aged 18-75yrs with a BMI of 30kg/m2 or more. 2. Individuals with a BMI of ≥27kg/m2 with existing risk factors such as diabetes, cardiac disease, obstructive sleep apnea or hypertension. 3. Individuals with a BMI of >30kg/m2, in whom at least 3 months of managed care (supervised diet, exercise, and behavior modification) fails to lead to significant reduction in weight. Two drugs have been licensed for use in the treatment of obesity: • Orlistat - prevents fat digestion and absorption by binding to gastrointestinal lipases; useful for those with a high intake of fat. • Sibutramine - reduces appetite and increases thermogenesis; recommended for those who cannot control their appetite. These drugs should not be used as sole therapy for obesity. Their use requires strict regular monitoring and must be discontinued if A. weight loss is <5% after 12 weeks of use or B. weight gain recurs while on the drugs • Anti-obesity drug treatment should not be used beyond a year and • Never beyond two years as few studies have examined the consequences of their long-term use • Gradual reversal of weight loss is known to occur on stopping pharmacotherapy Question 9: Mark the following statements as either True or False: A. Obesity management requires an integrated multidisciplinary approach B. Regular exercise is the single best predictor for achieving long-term weight control C. Diet must exclude more fruit and vegetables, nuts, whole grains and include fatty and sugary foods D. The criteria for use of pharmacotherapy is a BMI > 20 kg/m2 with persistent co-morbidity E. A 5-10% reduction in body weight is sufficient to significantly improve medical conditions associated with obesity What Have I Learnt about Obesity? (1): • Obesity is the excessive accumulation of body fat, best defined by the Body Mass Index (or Quetelet's Index). • BMI is the universal and convenient measure of obesity. • It is calculated as weight divided by height squared (kg/m2). • The BMI-for-age is used to assess obesity in children. • In adults (age 18years and > 30 kg/m2,), obesity is defined by a BMI, while of overweight by a BMI between 25 and 29.9 kg/m2. • A child with a BMI-for-age >95th percentile is obese while one with a BMI-for-age >85th percentile is overweight. • The longer a child remains obese beyond age 3 years, the more likely that the obesity will persist into adulthood. 30% of obese children are also obese as adults. 70% obese adolescents end up as obese adults. • Obesity is believed to result from a complex interplay of several factors; genetic, environmental (lifestyle and dietary), cultural, socio-economic, psychological and medical conditions. • Obesity is a known risk factor for several life-threatening, chronic medical and metabolic conditions: hypertension, coronary artery disease, stroke, type II diabetes, cancers. • A 5 - 10% reduction in body weight has been shown to significantly improve medical conditions associated with obesity. What Have I Learnt about Obesity? (2): • Obesity has reached epidemic proportions in several developed countries of the world and is also creeping up in urban cities of the underdeveloped world. • Globally, there are more than 1.1 billion overweight adults, and at least 312 million of them are clinically obese. • 10% of all children worldwide are either overweight or obese, while 17.6 million children under the <5y are estimated to be overweight. • Rapid urbanization and economic development have led to changing lifestyles and diets across the world which promote excessive weight gain. • An increasing incidence of obesity is also being seen in the poor, developing countries of the world • Increase body weight is now the sixth most important risk factor contributing to the overall burden of disease worldwide