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Epidemiology of obesity

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Chronic Diseases

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Epidemiology of obesity

  1. 1. EPIDEMIOLOGY OF OBESITY
  2. 2. Background ■ One of the most commonest expression of unhealthy diet often combined with lack physical activity. ■ Indeed we are amidst an epidemic of obesity. ■ Over the past few decades there has been dramatic rise in the prevalence of obesity throughout the world including India. ■ It is estimated byWHO that globally over 1 billion (16%) adult are overweight and 300 million (5%) are obese. ■ In india prevalence of obesity among women is 12.6% & 9.3% in men. In other words more than 100 million individuals are obese in India.
  3. 3. The human phenotype is changing rapidly Increased body size and fatter body composition Response to environments that make low demands on energy expenditure, together with greater energy- density diets This change is occurring within one to three generations, around the world Not entirely an urban phenomenon, but more pronounced in big cities
  4. 4. India : Double Burden of Disease Under nutrition due to Poverty 30 % below BPL Over nutrition and Obesity 5-7% MIG and HIG Urban area This is most productive workforce of the country Academics/Planners/ Administrators/ Professionals SHOULD BE GIVEN PRIORITY Current scenario: Global & India
  5. 5. Author Year of Study Country/ State Criteria used Prevalence of over- weight (M/F) Prevalence of obesity (M/F) Gopinath et.al 1994 Delhi BMI>25 21.3% (M) 33.4% (F) INA Singhal et al 1998 Jaipur BMI>25 14.6% (M) 6.6% (F) INA Asthana et al 1997 Varanasi BMI>25 30.2% (F) INA Chadha et al 1997 Delhi BMI>25 20.7 (M) 32.6% (F) INA ObesityTrends in India : Recent studies:Adults
  6. 6. Author Year of Study Country/ State Criteria used Prevalence of over- weight (M/F) Prevalence of obesity (M/F) Singh et.al 1999 5 Cities BMI>23 BMI>25 BMI>27 50.9% (F) Vasanthanani 2000 Coimbatore BMI>30 36.0% (M) Mohan et al 2000 Chennai BMI>25 38.0% (M) 33.1% (F) Easwaran et al 2001 Coimbatore BMI>25 BMI>24 65.0% (M) 65.0% (F) Gupta et al 2002 Jaipur BMI>27 24.5% (M) 30.2% (F) NFHS-II 1998- 99 India BMI>25 8.6% MIG 27.2 HIG ObesityTrends in India : Recent studies
  7. 7. Survey Normal (%) BMI 18.5-25 Obese (%) BMI>25 NNMB (75-79) 48.8 3.4 NNMB (88-90) 46.6 4.1 NNMB (94) 46.3 6.6 NNMB Slum (93-94) 51.7 11.6 Trends in Body Mass Index of Adult Women Body Mass Indix (BMI) is defined as weight (kg)/height² (m)
  8. 8. ObesityTrends in India : Recent studies Children S.No Author Name State/ country Prevalence of obesity 1.* Umesh Kapil etal, 2001 Delhi (India) 8% boys 6% girls 2.** Vedavati S etal, 1998 Chennai, India 6% obese 1.* Indian Pediatrics, 2002 May, 17: 449-452 2.** Indian Pediatrics, 2003 Aug, 40: 775-779.
  9. 9. Obesity Trends* Among U.S. Adults BRFSS, 1990 *BMI ≥30, or ~ 30 lbs. overweight for 5’ 4” person No Data <10% 10%–14% http://www.cdc.gov/nccdphp/dnpa/obesity/
  10. 10. Obesity Trends* Among U.S. Adults BRFSS, 1998 (*BMI ≥30, or ~ 30 lbs. overweight for 5’ 4” person) No Data <10% 10%–14% 15%–19% ≥20%
  11. 11. Obesity Trends* Among U.S. Adults BRFSS, 2006 (*BMI ≥30, or ~ 30 lbs. overweight for 5’ 4” person) No Data <10% 10%–14% 15%–19% 20%–24% 25%–29% ≥30%
  12. 12. What are the determinants of obesity? ■ Obesogenic environment: – Affluent lifestyle, sedentary home environment, vanishing old family tradition and cultures, energy rich food, lack of exercise & out door activities. ■ Age: – Incidence increasing with age till age of 60 due to hormonal and other biological changes in a body. ■ Gender: – Females are more likely to prone as compare to male due inherent physiological factors. ■ Ethinicity: – Unexplained variation are prevalent in different ethnic groups.
  13. 13. ■ Educational level: – In India it is seen that educated people are more likely to be obese compared to less educated, as they are more likely to be affluent but in western countries it is revers as educated people are more likely to be aware and concern about health problems. ■ Income: – Directly proportional of income in India. ■ Marital status: – Obesity is more among married people. ■ Parity: – Women with more parity are likely to be obese. ■ Diet: – Diet rich in fat, sugar & refined food is responsible for obesity. What are the determinants of obesity?
  14. 14. ■ Smoking: – Smoking per se reduces obesity by virtue of Nicotine being an anorexic agent. ■ Alcohol: – Alcohol provides 7Kcal/gm double than the carbohydrate and more over snacks consumed along with alcohol provide additional calories. ■ Physical inactivity: – High physical activity is a vital component to keep high fat & obesity under check. What are the determinants of obesity?
  15. 15. ■ Increased energy intake ■ Passive over eating: Physiological hunger & psychological hunger. ■ Binge eating ■ Decreased energy expenditure ■ Metabolic factors: Cushing’s syndrome, hypothyroidism etc. ■ Genetic factors ■ Fetal programming: Barker’s hypothesis What are the causes of obesity?
  16. 16. Critical period of obesity ■ Age range of 12 to 18 months ■ Age range of 12 to 16 years ■ During pregnancy Quantification of Obesity: ■ BMI: weight (Kg)/Height (m)2 ■ Waist circumference: 90 cm for men & 80 cm for women ■ Waist-Hip ratio: <0.9 for men & <0.8 for women Types of Obesity ■ Gynoid / pear shaped: Fat evenly distributed ■ Androd / apple shaped: Fat is deposit centrally or on abdominal region.
  17. 17. Risk factor for Non Communicable Diseases  Cardiovascular diseases CAD, CHF, Stroke  Insulin Resistance and Type-2 Diabetes Mellitus  Reproductive disorders  Pulmonary diseases  Gall stone disease  Cancer- Colon, Rectum, Prostate-Male  Gall stone–bile duct, breast, endometrium cervix, ovary- Female  Bone: Joint and skin diseases  Oesteoprosis  Mental Health  Psychological well being  Accidents  Muscloskeletal injuries Obesity Hazards of obesity
  18. 18. Diabetes Gall bladder disease Hypertension Dyslipidaemia Insulin resistance Breathlessness Sleep apnoea Greatly increased (relative risk >>3) Coronary heart disease Osteoarthritis (knees) Hyperuricaemia and gout Moderately increased (relative risk ca 2-3) Cancer (breast cancer in postmenopausal women, endometrial cancer, colon cancer) Reproductive hormone abnormalities Polycystic ovary syndrome Impaired fertility Low back pain Increased anaesthetic risk Foetal defects arising from maternal obesity Slightly increased (relative risk ca 1-2) Relative risk of health problems associated with obesity in developed countries.
  19. 19. High Prevalence of Metabolic Syndrome (Syndrome X) Hypertension Increased Insulin Resistance Central Obesity Dyslipidemia
  20. 20. Obesity and Mortality Morbidly obese individuals (more than 200% ideal body weight) have as much as a twelve fold increase in mortality
  21. 21. Source: Bray GA. 1992. AJCN; 55; 488S-94S
  22. 22. Obesity and Diabetes As many as 80% of patients with type-2 diabetes mellitus are obese
  23. 23. 4% 4-6% 6% n/a Source: Mokdad et al., Diabetes Care 2000;23:1278-83 Prevalence of Diabetes among U.S. Adults, BRFSS, 1993-94
  24. 24. Prevalence of Diabetes among U.S. Adults, BRFSS, 1997-98 4% 4-6% 6% n/a Source: Mokdad et al., Diabetes Care 2000;23:1278-83
  25. 25. Obesity and Diabetes Mild obesity Two fold risk of Diabetes Moderate obesity Five fold risk of Diabetes Severe obesity Ten fold risk of Diabetes
  26. 26. Indian Scenario : Diabetes Between 1988 and 2000, there was a 70% increase in the prevalence of Diabetes in the city of Chennai The recent study document a prevalence of 13% in adults
  27. 27. Possible Reasons: Average per capita energy ( Kcals ) intake as per expenditure classes , India Expenditure Classes Urban (1972-73) Urban (1993-94) Lower 30% 1579 1682 Middle 40% 2154 2111 Top 30% 2572 2405 Source: NSSO, 1997
  28. 28. Average daily per capita dietary intake of Fats in India Year Fat (g) Rural Fat(g) Urban 1972-73 24 36 1983 27 37 1993-94 31.4 42 1999-2000 36.1 49.6 Source: NSSO 2001
  29. 29. Life style changes between 1972-2000 Increase in Sedentary Life style Decrease Physical activities Intake of calories remaining same Increase in Fat intake Most manual jobs have been replaced by mechanized jobs Transportation to school /work place universally by use of motor car/Bus/Bicycles Increase in hours for activities :TV viewing/ Computer
  30. 30. Role of Physical Activity According to WHO at least 30 minutes of cumulative moderate exercise (equivalent to walking briskly) for all ages plus for children , an additional 20 minutes of vigorous exercise ( equivalent to running) three times a week . (These recommendations are basically for prevention of CHD). The prevention of obesity may require combination of both : more Physical Activity and Dietary interventions.
  31. 31. Body Mass Index RelativeRisk Women Willett, Dietz & Colditz, N.E.J.M. 1999. 341, 426-434 BMI in relation to morbidity over 18 yearsBMI in relation to morbidity over 18 years Aged 30-55 at start. 1 2 3 4 5 6 0 <21 22 23 24 25 26 27 28 29 30 Type 2 diabetes Cholelithiasis Coronary Heart Disease Hypertension
  32. 32. How to prevent? ■ “Most obese people won’t enter treatment, most who do won’t lose weight and most who lose weight regain it”. - Stukard
  33. 33. Prevention ■ Universal prevention: – Targeted towards all the individual in the community irrespective of their weight. – Measures like health diet, physical activity, shunning sedentary life style forms as strategy. Nutrition education also plays vital role. ■ Selective prevention: – High risk individuals are targeted. Adolescent, pregnant, middle aged and those with sedentary life style consuming high energy food under psychological stress. ■ Indicated prevention: – Secondary prevention for those with existing problems of overweight & obesity.
  34. 34. How to reduce weight?
  35. 35. Likely questions ■ LAQ: – Describe epidemiology of obesity. How would you advice a middle aged man of 90 kg and 170 cm tall to reduce wt.? – Discuss principles of a healthy diet in context of lifestyle diseases. ■ SAQ – Fad diet – Food pyramid – BMI – Benefits of wt. loss

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