Obesity

As a chronic disease it is prevalent in both developed and developing countries, and affecting children(10-20%) as well as adults(20-40%).Excess weight gain invites many associated diseases.

1. Obesity Dr Rajesh Kumar Ludam P.G Student, Dept of Community Medicine

2. Introduction Obesity may be defined as an abnormal growth of the adipose tissue due to an enlargement of fat cell size (hypertrophic obesity) or an increase in fat cell number (hyperplasic obesity)or a combination of both. Expressed in terms of body mass index (BMI). weight gain affects the risk associated with obesity, and the kind of disease that results. As a chronic disease, prevalent in both developed and developing countries, and affecting children(10-20%) as well as adults(20-40%). The most prevalent form of malnutrition.

3. Epidemiological determinants-: - Age - Sex - Genetic Factor - Physical Inactivity - Socio-economic Status - Eating Habits - Psychological Factors - Familial Tendency - Endocrine Factors - Alcohol & Smoking - Education - Ethnicity - Drugs

4. A)Age-: Obesity can occur at any age, and generally increases with age. Infants with excessive weight gain have an increased incidence of obesity in later life. - most adipose cells are formed early in life. B) SEX-: Women generally have higher rate of obesity than men, although men may have higher rates of overweight. - In the Framingham, USA study, men were found to gain most weight between the ages of 29 and 35 years, while women gain most between 45 and 49 gears of age. - W oman's BMI increases with successive pregnancies with a wt gain of 1 kg per pregnancy

5. C)Genetic Factors-: Twin studies have shown a close correlation between the weights of identical twins even when they are reared in dissimilar environments. - Recent studies have shown that the amount of abdominal fat was influenced by a genetic component accounting for 50-60 per cent of the individual differences. D)Physical Inactivity- : Physical activity and physical fitness are important modifiers of mortality and morbidity related to overweight and obesity. - Physical inactivity may cause obesity, which in turn restricts activity. This is a vicious circle. - Sedentary lifestyle particularly sedentary occupation and inactive recreation such as watching television promote it.

6. E)Socio-economic Status-: There is a clear inverse relationship between socio-economic status and obesity. - Within some affluent countries, however, obesity has been found to be more prevalent in the lower socio-economic groups. F)Eating Habits-: The composition of the diet, the periodicity with which it is eaten and the amount of energy derived from it are all relevant to the aetiology of obesity. - A diet containing more energy than needed may lead to prolonged post- prandial hyperlipidaemia and to deposition of triglycerides in the adipose tissue resulting in obesity - heavy advertisement of fast food outlets of energy-dense, micronutrient poor food and beverages is disturbing our eating habits.

7. G) Psychosocial Factors -: Psychosocial factors (e.g. emotional disturbances) are deeply involved in the aetiology of obesity. - Overeating may be a symptom of depression, anxiety, frustration and loneliness in childhood as in the adult life. H)Familial Tendency : Obesity frequently runs in family(obese parents frequently having obese children), but not necessarily explained solely by the influence of genes. I)Endocrine Factors-: These may be involved in occasional cases. e.g. Cushing's syndrome, growth hormone deficiency. J)Alcohol-: A recent review of studies concluded the relationship between alcohol consumption and adiposity generally positive for men and negative for women.

8. K)Education-: In most affluent societies. there is an relationship between educational level and prevalence of overweight . L)Smoking-: In most populations, smokers weigh somewhat less than ex-smokers: individuals who have never smoked fall somewhat between the two. M)Ethnicity-: Ethnic groups in many industrialized specially appear to be especially susceptible to the development of obesity and its complications. - Evidence suggest that this may be due to a genetic predisposition to obesity that only becomes apparent when such groups are exposed to a more affluent life style N)Drugs-: Use of certain drugs,e.g.corticosteroids,contraceptives. insulin, p-adrenergic blockers, etc. can cause weight gain.

9. Use of BMI to Classify Obesity Body mass index (BMI) is a simple index of weight-for-height that is commonly used to classify underweight, over weight and obesity in adults. It is defined as the weight in Kilograms divided by the square of the height in metres (kg/m²). example, an adult who weighs 70 kg and whose height is 1.75 mtr will have a BMI of 22.9 BMI= 70 (kg)/17.75²(m²) =22.9 The WHO classification is based primarily on the association between BMI and mortality.

10. These BMI values are age-independent and the same for both sexes. The risks associated with increasing BMI are continuous and graded and begin at a BMI above 25. BMI does not distinguish between weight associated with muscle and weight associated with fat. In addition, the percentage of body fat mass increases with age up to 60-65 years in both sexes. and is higher in women than in men of equivalent BMl.

11. Assessment Of Obesity Body composition are as under-: a. the active mass (muscle, liver, heart etc.) b. the fatty mass (fat) c. the extracellular fluid (blood, lymph, etc.) d. the connective tissue (skin. bones. Connective The most widely used criteria are : BODY WEIGHT SKIN FOLD THICKNESS WEIST HIP RATIO OTHERS

12. Skin Fold Thickness-: It is a rapid and "non-invasive” method for assessing body fat. Several varieties of callipers (e.g., Harpenden skin callipers) - The measurement may be taken at all the four sites - mid-triceps, biceps, sub scapular and suprailiac regions. - The sum of the measurements should be less than 40 mm in boys and 50 mm in girls Waist-Hip Ratio-: There is an increased risk of metabolic complications for men with a waist circumference > 102 cm, and women with a waist circumference > 88 cm - Over the past 10 years or so, it has become accepted that a high WHR (> 1.0 in men and > 0.85 in women) indicates abdominal fat accumulation.

13. Risk Of Health Problems With Obesity

14. Hazards Of Obesity Increased Morbidity Increased Mortality

15. Prevention And Control Dietary Changes Increased Physical Activity Others-: - Surgical treatment gastric bypass, gastroplasty, jaw wiring -Health education has an important role to play in teaching how to reduce overweight and prevent obesity.