OBESITY

Introduction Obesity is unhealthy accumulation of body fat. In adults, damaging effects of excess weight are seen when the body mass index exceeds 25kg/m2. Obesity is defined as having a body mass index of >30 kg/m2. Obesity is the most common metabolic/nutritional disease in the U.S.

Introduction More than 50% of the adult population is overweight. Obesity is more common in women minorities and the poor. Obese individuals have an increased risk of developing diabetes mellitus, hypertension, heart disease, stroke, fatal cancers and other illnesses. In addition, obese individuals may suffer psychologically and socially.

Epidemiological information The prevalence of obesity in the USA is high and rising higher. In the past decade, the overall prevalence rose from 25 to 33% an increase of 1/3. prevalence varies significantly by sex, age, socioeconomic status, and race. Prevalence is 35% among women and 31% among men and it more than doubles between the age of 20 and 55.

Epidemiological information Among women, obesity is strongly associated with socioeconomic status, being twice as common among those with lower socioeconomic status as it is among those with higher status.

Epidemiological information Although prevalence among black and white men does not differ much, obesity is far more common among black than among white women, affecting 60% of middle-aged black women compared with 33% of white.

Aetiology The cause of obesity is expending less energy than is consumed. Weight is regulated with great precision. Regulation of body weight is believed to occur not only in persons of normal weight but also among many obese persons,

Aetiology in whom obesity is attributed to an elevation in the set point around which weight is regulated. The determinants of obesity can be divided into the genetic, the environmental and the regulatory.

Genetic determinants Recent discoveries have helped explain how genes may determine obesity and how they may influence the regulation of body weight. The existence of leptin supports the idea that body weight is regulated, because leptin serves as a signal between adipose

Genetic determinants tissue and the areas of the brain that control energy metabolism, which influences body weight. The extent of genetic influences on human obesity has been assessed by twin, adoption and family studies .

Genetic determinants In the first studies, of twins, the heritability of the BMI was estimated to be very high , about 80%. The result of adoption and family studies agree on a heritability of 33% which is more reasonable than that of the twin studies. Genetic influence may be more important in determining regional fat distribution than total body fat

Environmental Determinants The fact that genetic influences account for only 33% of the variation in body weight means that the environment exerts a huge influence dramatically illustrated by the marked increase in the prevalence of obesity in the past decade.

Socioeconomic Status Has an important influence on obesity, particularly among women. The negative correlation between socioeconomic status and obesity reflects an underlying cause.

Socioeconomic Status Longitudinal studies have shown that growing up with lower socioeconomic status is a powerful risk factor for obesity. Socioeconomic factors are major influence on both intake and energy expenditure.

Food consumption Large food intake is associated with obesity. Obese persons have a large energy expenditure, which requires in turn a large food intake. Furthermore, this large food intake usually includes a large fat intake of food, which independently predisposes to obesity.

Sedentary lifestyle Is another major environmental influence promoting obesity. Physical activity not only expends energy but also helps control food intake. Animal studies suggest that physical inactivity contributes to obesity by a paradoxical effect on food intake.

Sedentary lifestyle Although food intake increases as energy expenditure increases, food intake may not decrease proportionately when physical activity falls below a minimum level, restricting activity may actually increase food intake for some people.

Regulatory Determinants: Pregnancy is a major determinant of obesity in some women. Although most women weigh only a little bit more a year after delivery, about 15% weigh 20lb more with each pregnancy.

Regulatory Determinants: An increase in fat cells and adipose tissue mass during infancy and childhood and for some severely obese persons, even during adulthood, predisposes to obesity. This increase can result in five times as many fat cells in obese persons as in persons of normal weight.

Regulatory Determinants: Dieting reduces only fat cell size, not fat cell number. As result, persons with hypercellular adipose tissue can reduce to normal weight only by markedly lessening the lipid content of each cell.

Regulatory Determinants: Such depleting and the associated events at the cell membrane may set a biologic limit on their ability to lose weight and may explain their difficulty in reducing to a normal weight.

Brain Damage Caused by a tumor (especially craniopharyngioma) or an infection ( particularly affecting the hypothalamus) leads to obesity, the final common pathway to caloric balance lies in behavior mediated by the CNS.

Drugs The use of certain drugs, e.gcortico-steroids, contraceptives, Insulin and anti psychotics, can promote weight gain.

Familial Tendency Obesity frequently runs in families (obese parents frequently having obese children), but this is not necessarily explained solely by the influence of genes.

Endocrine factors These may be involved in occasional cases e.gcushing’s syndrome, growth hormone deficiency.

Alcohol A recent review of studies concluded that the relationship between alcohol consumption and adiposity was generally positive for men and negative for women. (refer to obesity taskforce document)

Education In most affluent societies, there is an inverse relationship between alcohol consumption, educational level and prevalence of overweight.

Smoking Reports that the use of tobacco lowers body weight began to appear more than 100 years age, but detailed studies have been reported only during the past 10 years or so. In most populations, smokers weigh somewhat less than ex-smokers; individuals who have never smoked fall somewhat between the two.

Ethnicity Ethnic groups in many industrialized countries appear to be especially susceptible to the development of obesity and its complication. However, this only becomes apparent when such groups are exposed to a more affluent life style

Risk factors Obesity occurs when you eat and drink more calories than you burn through exercise and normal daily activities. The body stores these extra calories as fat. Obesity usually results from a combination of causes and contributing factors, including:

Risk factors Genetics- genes may affect the amount of body fat one stores and where that fat is distributed. Genetics may also play a role in how efficiently the body converts food into energy and how it burns calories during exercise.

Risk factors Even when someone has a genetic predisposition, environmental factors ultimately make one gain more weight.

Nonclinical programs Health Practitioners can assist clients by helping them select programs with sensible low-fat diets and an emphasis on physical activities. Most programs teach clients how to make safe, sensible and gradual changes in eating patterns.

Nonclinical programs: Diet Changes include increased intake of complex carbohydrates (fruits, vegetables, breads and cereals)and decreased intake of fats and simple carbohydrates- Very low calorie diets providing 400 to 800 kcal/day.

Nonclinical programs: cont Inactivity. If one is not very active, one does not burn as many calories. With a sedentary lifestyle, one can easily take in more calories every day than one is burning off through exercise and normal daily activities.

Nonclinical programs: cont Unhealthy diet and eating habits. Having a diet that's high in calories, eating fast food, skipping breakfast, consuming high-calorie drinks and eating oversized portions all contribute to weight gain.

Nonclinical programs: cont Family lifestyle. Obesity tends to run in families, not just because of genetics. Why? Family members tend to have similar eating, lifestyle and activity habits. If one or both of your parents are obese, your risk of being obese is increased.

Nonclinical programs: cont Quitting smoking. Quitting smoking is often associated with weight gain. For some, it can lead to a weight gain of as much as several pounds a week for several months, which can result in obesity.

Nonclinical programs: cont In the long run, however, quitting smoking is still a greater benefit to your health than continuing to smoke. Pregnancy. During pregnancy a woman's weight necessarily increases. Some women find this weight difficult to lose after the baby is born. This weight gain may contribute to the development of obesity in women.

Nonclinical programs: cont Pregnancy. During pregnancy a woman's weight necessarily increases. Some women find this weight difficult to lose after the baby is born. This weight gain may contribute to the development of obesity in women. Lack of sleep. Not getting enough sleep at night can cause changes in hormones that increase your appetite. You may also crave foods high in calories and carbohydrates, which can contribute to weight gain. .

Nonclinical programs: cont Genetics. Your genes may affect the amount of body fat you store and where that fat is distributed. Genetics may also play a role in how efficiently your body converts food into energy and how your body burns calories during exercise. Even when someone has a genetic predisposition, environmental factors ultimately make you gain more weight.

Nonclinical programs: cont . Social and economic issues. Certain social and economic issues may be linked to obesity: no safe areas to exercise, unhealthy ways of cooking

Nonclinical programs: cont not having money to buy healthier foods. In addition, the people you spend time with may influence your weight — you're more likely to become obese if you have obese friends or relatives

Inactivity. If you're not very active, you don't burn as many calories. With a sedentary lifestyle, you can easily take in more calories every day than you burn off through exercise and normal daily activities.

Nonclinical programs: cont Age. Obesity can occur at any age, even in young children. But as you age, hormonal changes and a less active lifestyle increase your risk of obesity. In addition, the amount of muscle in your body tends to decrease with age.

Nonclinical programs: cont This lower muscle mass leads to a decrease in metabolism. These changes also reduce calorie needs and can make it harder to keep off excess weight. If you don't control what you eat as you age, you'll likely gain weight

Symptoms and Signs The symptoms and signs of obesity consist of the immediate consequences of the large adipose tissue mass. Prominent among them is sleep apenea, a seriously under diagnosed disorder, characterizes by moments during sleep when breathing ceases, as often as hundreds of times a night.

Symptoms and Signs In the obesity-hypoventilation syndrome ( pickwickian syndrome), impairment of breathing leads to hypercapnia, a reduced effect of carbon oxide in stimulating respiration, hypoxia, corpulmonale, and a risk of premature death.

cont Obesity may lead to orthopedic disturbances of weight-bearing and non-weight bearing joints. Skin disorders are particularly common, increased sweat and skin secretions, trapped in thick folds of skin, produces a culture medium conducive to fungal and bacterial growth and infections.

Symptoms and Signs For some young women in upper and middle socioeconomic groups, psychological problems are linked to obesity.

Management/Treatment Attempts to lose weight are often unsuccessful. Nonetheless, mild caloric restriction, an increase in physical activity and supportive therapies each have a role. Medication to enhance weight loss, such as amphetamines or amphetamine-like agents have had unacceptable side effects (e.g cardiac valvular injuries with fenfluramine/phentermine). Surgical remedies are available for some patients.

Prevention and control Weight control is widely defined as approaches to maintaining weight within the healthy (i.e ‘normal’ or ‘acceptable’) range of body mass index of 18.5 to 24.9 kg/m2 throughout adulthood (WHO expert committee, 1995). It should also include prevention of weight gain or more than 5kg in all people. In those who are already over-weight, a reduction of 5-10 per cent of body weight is recommended as an initial goal.

cont Prevention of obesity should begin in early childhood. Obesity is harder to treat in adults than it is in children. The control of obesity centres, increased physical activity and a combination of both. (a)DIETARY CHANGES: the treatment: the proportion of energy-dense foods such as simple carbohydrates and fats should be reduced; the fibre content in the diet should be increased through the consumption of common un-refined foods; adequate levels of essential nutrients in the low energy diets

cont The most consideration is that the food energy intake should not be greater than what is necessary for energy expenditure. It requires modification of the patient’s behaviour and strong motivation to lose weight and maintain ideal weight. Regular physical exercise is the key to an increased energy expenditure Appetite suppressing drugs have been tried in the control of obesity.

One should not expect quick or even tangible results in all cases from obesity prevention programmes. Health education has an important role to play in teaching the people how to reduced overweight and prevent obesity. A fruitful approach will be to identify those children who are at risk of becoming obese and find way of preventing it.

Prognosis and treatment The prognosis for obesity is poor, untreated, it tends to progress. With most forms of treatment, weight can be lost, but most persons return to their pre treatment weight within 5 years. The first is evidence that a modest weight loss, 10% or perhaps even 5% of body weight, is sufficient to control, or at least improve, most complication of obesity. The “10% solution” has become the goal of most treatment programs.

The second development, derived from the poor maintenance of weight loss during treatment, is a move from a goal of weight loss to one of weight management, achieving the best weight possible in the context of overall health. Weight management programs can be divided into three major categories.

Do-it-yourself programs Are the resource for most obese persons who seek help. They include self-help groups, such as overeaters anonymous and take off pounds sensibly (TOPS); community-based and work site programs; books and magazines articles; and weight loss products, such as meal replacement formulas

cont Certain medications. Some medications can lead to weight gain if you don't compensate through diet or activity. These medications include some antidepressants, anti-seizure medications, diabetes medications, antipsychotic medications, steroids and beta blockers.

Medical problems. Obesity can rarely be traced to a medical cause. Some medical problems, such as arthritis, can lead to decreased activity, which may result in weight gain. A low metabolism is unlikely to cause obesity, as is having low thyroid function.

PUBLIC HEALTH IMPORTANCE The World Health Organization (WHO) predicts that overweight and obesity may soon replace more traditional public health concerns such as undernutrition and infectious diseases as the most significant cause of poor health. Obesity is a public health and policy problem because of its prevalence, costs, and health effects. Public health efforts seek to understand and correct the environmental factors responsible for the increasing prevalence of obesity in the population.

CONT- Solutions look at changing the factors that cause excess food energy consumption and inhibit physical activity. Efforts include reimbursed meal programs in schools, limiting direct junk foodmarketing to children, and decreasing access to sugar-sweetened beverages in schools.

When constructing urban environments, efforts have been made to increase access to parks and to develop pedestrian routes. Many countries and groups have published reports pertaining to obesity. In 1998 US, published guidelines titled "Clinical Guidelines on the Identification, Evaluation and Treatment of Overweight and Obesity in Adults: The Evidence Report".

CONT- In 2006 the Canadian Obesity Networkpublished the "Canadian Clinical Practice Guidelines (CPG) on the Management and Prevention of Obesity in Adults and Children". This is a comprehensive evidence-based guideline to address the management and prevention of overweight and obesity in adults and children.

CONT- In 2004, the United Kingdom Royal College of Physicians, the Faculty of Public Health and the Royal College of Paediatrics and Child Health released the report "Storing up Problems", which highlighted the growing problem of obesity in the UK. The same year, the House of Commons Health Select Committee published its "most comprehensive inquiry [...] ever undertaken" into the impact of obesity on health and society in the UK and possible approaches to the problem.

CONT- In 2006, the National Institute for Health and Clinical Excellence (NICE) issued a guideline on the diagnosis and management of obesity, as well as policy implications for non-healthcare organizations such as local councils. A 2007 report produced by Sir Derek Wanless for the King's Fund warned that unless further action was taken, obesity had the capacity to cripple the National Health Service financially.

CONT- Comprehensive approaches are being looked at to address the rising rates of obesity. The Obesity Policy Action (OPA) framework divides measure into 'upstream' policies, 'midstream' policies, 'downstream' policies. 'Upstream' policies look at changing society, 'midstream' policies try to alter individuals' behavior to prevent obesity, and 'downstream' policies try to treat currently afflicted people.

Conclusion Obesity is now reaching pandemic proportions across much of the world, and its consequences are set to impose unprecedented health, financial and social burdens on global society, unless effective actions are taken to reverse the trend.

OBESITY

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