Obesity overview


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Obesity overview

  1. 1. Publication # 34 Obesity - BasicsPennington Biomedical Research Center Division of Education
  2. 2. Introduction and definition
  3. 3. Obesity: IntroductionA complex chronic disease with integration ofsocial, behavioral, cultural, physiological, andgenetic factors.Heart Disease was the number one leading cause ofdeath in 2010, second was cancer, fourth wasstroke, seventh was diabetes. All of these conditions -as well as depression, arthritis, and a host of others -are complications of obesity. PBRC 2012 3
  4. 4. Overweight is Rising 80 70 60 50 1900 1950 40 1970 30 1990 PercentOverweight 20 2008 10 0 % Overweight and Obesity Time PBRC 2012 4
  5. 5. Body Mass Index (BMI)BMI equals a persons weight in kilograms divided byheight in meters squared. (BMI=kg/m2)Is a measurement taken into account by physiciansand researchers studying obesity BMI uses a mathematical formula that takes into account both a persons height and weight 1kg= 2.2 pounds 1 inch= 2.54 cm PBRC 2012 5
  6. 6. ClassificationBody mass index (BMI) kg/m2 – Optimal BMI is 20-25 – Overweight is a BMI of 27 or greater – Obese BMI is 30 or greaterYou can find tables on the web that have done the mathand metric conversions for you. Simply locate yourheight in inches and weight in pounds to calculate BMI.Example of a chart: – http://www.nhlbi.nih.gov/guidelines/obesity/bmi_tbl.pdf PBRC 2012 6
  7. 7. Risk of Associated DiseaseAccording to BMI and Waist Size Waist less than Waist greater BMI or equal to than 40 in. (men) or 40 in. (men) or 35 in. (women) 35 in. (women) 18.5 or less Underweight --- N/A 18.5 - 24.9 Normal --- N/A 25.0 - 29.9 Overweight Increased High 30.0 - 34.9 Obese I High Very High 35.0 - 39.9 Obese II Very High Very High 40 or Obese III Extremely Extremely greater High High PBRC 2012 7 http://www.cdc.gov/healthyweight/assessing/bmi/adult_bmi/index.html#Definition
  8. 8. Why is BMI of 20-25 considered as a reference weight? This is because the relationship between morbidity and mortality and BMI was minimal at that range 2.5 2 1.5 Risk 1Increased risk 0.5 0 19 20 25 35 PBRC 2012 Body Mass Index 8
  9. 9. BMI With the exception of highly trained athletes, Body Mass Index is a good predictor of chronic disease and mortality.Currently, about 74% of American adults are overweight and about 39.5% are obese. PBRC 2012 9
  10. 10. Cell sizeAll obese individuals have increased adipose cell size.As an adult gains weight, generally cell sizeincreases, not cell numberSo, the number of fat cells can be associated with theage of onset of obesity.For adults with a higher number of adipose cells, thiswould indicate that obesity was present in earlychildhood. PBRC 2012 10
  11. 11. Total # of adipose cells in adults 100 90 80 70 60 LeanIncreasing in 50 Obese 40 number 30 20 x106 10 0 L Men L Women O-Men O-Women PBRC 2012 11
  12. 12. Waist CircumferenceIs a predictor of mortality and chronic diseaseIs a prognostic indicator along with BMIThe presence of excess body fat in theabdomen, when out of proportion to total body fat, isconsidered an independent predictor of risk factorsand ailments associated with obesity. Men = Greater than 40 inches Women = Greater than 35 inches PBRC 2012 12
  13. 13. Obesity classesClass 1 – BMI of 30-35Class 2 – BMI of 35-40Class 3, Extreme obesity – BMI greater than 40 PBRC 2012 13
  14. 14. Facts on ObesityAll health problems are more common in in obesewomen than in men, with the exception of cardiacheart disease.Excess weight and even modest weight gainssubstantially increase the risk of Hypertension inadult women.Weight loss reduces this risk PBRC 2012 14
  15. 15. Facts on ObesityLow resting metabolic rate (RMR) in formerlyobese persons may be genetic or acquired andmay contribute to weight regain once an individualis successful in a 10% weight loss.Visceral adipose tissue (VAT) distribution is animportant determinant of RMR in men andpostmenopausal women. PBRC 2012 15
  16. 16. Co-morbidities
  17. 17. Morbidity and Mortalityassociated with ObesityIndividuals are at greater risk for developing: Cardiovasular disorders – Hypertension – Stroke – Ischemic heart disease PBRC 2012 17
  18. 18. HypertensionBlood pressure is often increased in overweightindividuals.Estimates suggest that control of overweight wouldeliminate 48% of the hypertension in Caucasians and28% in African Americans.Overweight and hypertension interact with cardiacfunction, leading to thickening of the ventricular wallsand larger heart volume over time, and thus to a greaterlikelihood of cardiac failure. PBRC 2012 18 Bellanger T, Bray G. Journal of the Louisiana State Medical Society.2005
  19. 19. Prevalence of HTN in overweight and obese individuals PBRC 2012 Adapted from: 19 http://www.obesityinamerica.org/trends.html
  20. 20. Stroke Bellanger T, Bray G. Journal of the Louisiana State Medical Society.2005Ischemic stroke occurs when an artery to thebrain is blocked.Normally, blood containing oxygen and nutrients isdelivered to the brain and carbon dioxide and cellularwastes are removed.The risk for ischemic stroke in men and women isincreased in both overweight and obesity.However, overweight and obesity do not increase therisk for hemorrhagic strokes. PBRC 2012 20
  21. 21. Morbidity and Mortalityassociated with Obesity Gastrointestinal disorders – Colon cancer – Diverticulosis – Gall stones – Hemorrhoids PBRC 2012 21
  22. 22. Gall stonesWhen compared to those having a BMI of 24 or less, – women with a BMI greater than 30 had a 2-fold increased risk for symptomatic gallstones. – those with a BMI greater than 45 had a 7-fold increase.Relative increased risk of symptomatic gallstones occurringwith increasing BMI is less for men than for women.Obese patients that lose weight rapidly, possibly fromgastric surgery, are at risk for development of gallstones.There are medications to reduce the likelihood of gallstonedevelopment. PBRC 2012 22 Bellanger T, Bray G. Journal of the Louisiana State Medical Society.2005
  23. 23. Morbidity and Mortalityassociated with Obesity Metabolic disorders – Diabetes mellitus – Dyslipidemia PBRC 2012 23
  24. 24. Diabetes MellitusType 2 DM is strongly associated with overweight andobesity in both genders and in all ethnic groups.Risk for Type 2 DM increases with the degree andduration of overweight, along with greater centraldistribution of body fat (abdominal).Weight loss or moderating weight gain over yearsreduces the risk of developing diabetes. PBRC 2012 24 Bellanger T, Bray G. Journal of the Louisiana State Medical Society.2005
  25. 25. Diabetes MellitusIn the Health Professionals Follow-up Study, a weightloss of 5-11 kg decreased the relative risk fordeveloping diabetes by nearly 50%.Type 2 DM was almost nonexistent with a weight lossof more than 20 kg or in those with a BMI below 20. PBRC 2012 25
  26. 26. Obesity and Type 2 DMAmong people diagnosed with Type 2 diabetes, 67 percenthave a BMI > 27 (classified in the overweight range) and 46percent have a BMI > 30 (classified as obese).Obesity increases the risk for Type 2 diabetes in women morethan 90 times for those with a BMI in the Class 2 range andabove, and more than 40 times for men with a BMI in the Class2 range and above. PBRC 2012 26 Adapted from: http://www.obesityinamerica.org/trends.html
  27. 27. Morbidity and Mortalityassociated with Obesity Musculoskeletal disorders – Degenerative joint disease PBRC 2012 27
  28. 28. Morbidity and Mortality associated with obesity Other – Sleep apnea– Endometrial, prostate, and breast cancers – Complications of pregnancy – Menstrual irregularities – Psychological disorders PBRC 2012 28
  29. 29. CancerOverweight and obesity are associated with anincreased risk of:esophageal, gallbladder, pancreatic, cervical, breast,uterine, renal, and prostate cancers.Excess body weight, poor nutrition, or physical inactivityaccount for 30 percent of several major cancers,including--- colon, breast (postmenopausal),endometrial, kidney, and cancer of the esophagus.Excess body weight contributes to as many as 1 out of 5of all cancer-related deaths. PBRC 2012 29 Bellanger T, Bray G. Journal of the Louisiana State Medical Society.2005; www.cancer.org, 2012
  30. 30. InfertilityIrregular menses, amenorrhea, and infertility areassociated with obesity.For women with a BMI greater than 30, abnormalities inthe secretion of hypothalamic gonadotropin releasinghormone (GnRH), pituitary luteinizing hormone(LH), and follicle stimulating hormone (FSH) are likelyto be present. This results in anovulation. PBRC 2012 30 Bellanger T, Bray G. Journal of the Louisiana State Medical Society.2005
  31. 31. Relative risk of death in women 2.4 2.2 2 1.8 Risk 1.6Increased 1.4 Risk 1.2 1 19 19-21.9 22-24.9 25-26.9 27-28.9 29-31.9 32 PBRC 2012 Body Mass Index 31 NEJM 1995;333:677-685.
  32. 32. Total cost of Obesity The medical care costs of obesity in the United States arestaggering. In 2008 dollars, these costs totaled about $147 billion.Direct and indirect costs comprise this total, and are roughly equal.Direct Costs: include medical expenditures forpreventative, diagnostic, and treatment services.Indirect Costs: include lost wages resulting from people beingunable to work because of illness. PBRC 2012 CDC, 2012 32
  33. 33. Death rates due to obesity Obesity is associated with over 112,000 excess deaths due to cardiovascular disease, over 15,000 excess deaths due to cancer, and over 35,000 excess deaths due to non-cancer, non-cardiovascular disease causes per year in the U.S. population, relative to healthy- weight individuals.. Reported that there are > 400,000 deaths a year attributed to tobacco-related diseases. 2007 PBRC 2012 33
  34. 34. Prevalence
  35. 35. Prevalence In 1991 In 10 0 states had obesity4 states had obesity prevalence rates of prevalence rates of 15-19 percent 15–19 percent 15 states had rates of 20-24 percentNo state had a rate at or above 20 36 states had rates percent more than 25 percent PBRC 2012 35
  36. 36. From the CDC: For 2010 PBRC 2012 36
  37. 37. Comparisons: Adults: Youth:15% of the US adults, 20 Obesity was at 5% in years or > had a BMI of 1971-74. 30 or > in 1971-74 17% of children and Now 35.7% of the US teens ages 2-19 have a BMI of 30 or are obese according to >(2008) the 2007-2008 NHANES data PBRC 2012 37
  38. 38. Prevalence in the US:Overweight and Obesity in Women (2009-2010) Non-Hispanic black women – 58.6% Hispanic women – 40.7% Non-Hispanic white women - 33.4% PBRC 2012 38
  39. 39. Obesity by Age and Race: In the US PBRC 2012 39 http://www.gallup.com/poll/142736/obesity-peaks-middle-age.aspx
  40. 40. Obesity by Income Level: In the US PBRC 2012 40
  41. 41. Obesity in other countries Italy: 8.9% Germany: 14.7% England: 26% Japan: 3.2% PBRC 2012 41
  42. 42. Critical periods of growth
  43. 43. Periods of rapid growth Childhood Teen age years Pregnancy PBRC 2012 43
  44. 44. Obesity in children: Facts Among children older than 3, obesity is a strong predictor of adult obesity Parental obesity more than doubles the risk of adult obesity among both obese and non-obese children under 10. PBRC 2012 44
  45. 45. Ten State Nutrition SurveyThe study follows girls and boys born to different parental combinations, measuring and recording skin fold thickness each year from age three until seventeen. Depending on which combination the child was born to, this either puts the child at higher or lower risk for being overweight later in life. Uses 5 different parental combinations: Lean and Lean Medium and Lean Medium and Medium Medium and Obese Obese and Obese PBRC 2012 45
  46. 46. 5 Parental fatness combinationsLean Lean Medium Lean Medium Medium L-L M-L M-M PBRC 2012 46
  47. 47. 5 Parental fatness combinations Obese Medium Obese Obese O-M O-O PBRC 2012 47
  48. 48. Tricep skinfold in boys Parental Fatness 30 Combinations 25 O-O 20 O-M 15 M-M M-L 10Mm L-L 5 0 3 5 7 9 11 13 15 17 PBRC 2012 Age (Years) 48
  49. 49. Tricep skinfold in girls Parental Fatness 30 Combinations 25 O-O 20 O-M 15 M-M M-LMm 10 L-L 5 0 3 5 7 9 11 13 15 17 Age (years) PBRC 2012 49
  50. 50. Obesity in childrenComparing the children of obese with the children oflean, it was striking both how fat the children of theobese were, and how fast they gained their fatness.By age 17, the children of two obese parents werethree times as fat as the children of two lean parents. PBRC 2012 50 Ten State Nutrition Survey
  51. 51. Childhood antecedents to obesityParental weight TV viewingSocial class # siblingsRace Maternal ageOne-parent High caloric intakehousehold High dietary fatEducational level intakeParental income Physical activity levelParental Reduced Thermicemployment Effect of Food PBRC 2012 51
  52. 52. SE & ObesityHigher socioeconomic group women: diet more often have greater access to resources have better nutrition knowledge are committed to slimness avoid high fat foods get more physical activity PBRC 2012 52
  53. 53. Effect of SocioeconomicGroup in the Developing Countries Completely reversed Higher socioeconomic classes have more incidence of obesity Less malnutrition Less infection Steady source of income and food Overweight is associated with wealth PBRC 2012 53
  54. 54. Obesity versus SE ThinnessPrevalence Obesity Affluence PBRC 2012 54
  55. 55. Diet and obesity
  56. 56. Energy balanceBody weight is a function of energy and nutrient balanceover an extended period of time.Energy balance is determined by macronutrientintake, energy expenditure, and nutrient partitioning.Some possible causes of obesity include:Cessation of smoking, over-consumption of high fatfoods, a decrease in the level of activity, and aging. PBRC 2012 56
  57. 57. Fat versus carbohydrate Fat is more energy dense than carbohydrates, yielding 38kJ/g versus carbohydrates 17kJ/g. 9 kcals/g of fat versus 4.0 kcals/g of carbohydrate Fats lend flavor and palatability to foods contributing to greater preference for them. Carbohydrates have greater thermogenic effect than fats. PBRC 2012 57
  58. 58. Dietary fat versus calories Reducing dietary fat has very little effect on reducing body weight as long as energy balance is met. Total calories and caloric balance is more important Overeating is necessary initially for weight gain to occur PBRC 2012 58
  59. 59. Dietary fat intake is decreasingwhile Obesity is increasing.1970’s people ate an average of– 85 grams of fat– 1,837 kcal1994 people ate an average of– 73 grams of fat– 1,949 kcal1994-96 people ate an average of– 76. 4 grams of fat– 2,056 kcal– Although we are still consuming less fat, we are consuming more (larger portion sizes), contributing to more calories consumed per day than in the 1970’s. PBRC 2012 Chanmugam et al 2003. 59
  60. 60. Heritability of obesity
  61. 61. Genetics and Environment Allindividuals Those genetically predisposed Clinically affected ~3% Portion subject to adverse PBRC 2012 environmental 61 conditions
  62. 62. GeneticsObesity is probably genetically predisposed in asmall percent of the population.The National Institutes of Health (NIH) estimates thatenvironment contributes 40-60% of weightdetermination. PBRC 2012 62
  63. 63. Obesity GenesCommon variants in three genes have been associatedwith an increased risk for obesity– Individuals who have 12 variants in their 3 genes could gain around 6 kg of extra body weight compared to someone who does not (13+ pounds of extra weight) PBRC 2012 63 Nature Genetics (2009) 41: 140.
  64. 64. HeritabilityIdentical twins reared apart yield highestheritability levels ~70%Adoption studies yield lowest habitabilityestimates ~30%True heritability for BMI is about~25-40% already determined. PBRC 2012 64
  65. 65. Human obesity genes: Pennington Biomedical Research CenterAn abundance of research is currently being conducted on human obesity genes and their role in the development of obesity in individuals.There are at least 135 different genes in humans that have been associated and/or linked with obesity-related phenotypes. Currently 22 genes have been identified in several studies including the following 12 in up to 10 studies: PPARG, ADRB3, ADRB2, LEPR, GNB3, UCP3, ADIPOQ, L EP, UCP2, HTR2C, NR3C1, and UCP1. The genes have been found distributed in all chromosomes except Y. Rankinen et al. OBESITY Vol. 14 No. 4 April 2006 PBRC 2012 65
  66. 66. Future Directions Obesity is a chronic disorder which is currently on the rise. One should set realistic goals for weight loss. Even modest weight losses of 5-10% initial body weight show improvements in overall health and decreased risk for complications from chronic disease. Behavioral treatment is necessary with a focus on relapse prevention. Combination treatments are often incorporated– Drug, diet, exercise, behavior PBRC 2012 66
  67. 67. Thank You!
  68. 68. Referenceshttp://www.contracostatimes.com/mld/cctimes/8145335.htm?template=contentModules/printstory.jsp&1chttp://www.consumer.gov/weightloss/bmi.htmhttp://www.cdc.gov/nccdphp/dnpa/obesity/defining.htmhttp://www.wvdhhr.org/bph/oehp/obesity/economic.htmhttp://www.cdc.gov/nccdphp/dnpa/obesity/trend/maps/index.htmhttp://www.cdc.gov/nchs/pressroom/04facts/obesity.htmhttp://www.uic.edu/depts/mcam/nutrition/pdf/EnergyBalance.pdf#search=energy%20expenditure%20RMR%20thermogenesis‘http://win.niddk.nih.gov/publications/gastric.htmEscott-Stump, S. Nutrition and Diagnosis-Related Care. 5th Edition.2002 PBRC 2012 68
  69. 69. Referenceshttp://www.americanheart.org/presenter.jhtml?identifier=4720http://www.strokecenter.org/pat/ais.htmhttp://cis.nci.nih.gov/fact/3_70.htmhttp://www.obesityinamerica.org/trends.htmlhttp://obesitygene.pbrc.edu/~eesnyder/papers/OGM2003_paper.pdfhttp://www.google.com/imghp?hl=en&tab=wi&qRankinen et al. OBESITY Vol. 14 No. 4 April 2006http://www.gallup.com/poll/142736/obesity-peaks-middle-age.aspxNature Genetics (2009) 41: 140 PBRC 2012 69
  70. 70. Pennington Biomedical Research Center Division of EducationDivision of EducationPhillip Brantley, PhD, DirectorPennington Biomedical Research CenterClaude Bouchard, PhD, Executive DirectorHeli J. Roy, PhD, RDShanna Lundy, BSBeth Kalicki PBRC 2012 70
  71. 71. About Our CompanyThe Pennington Biomedical Research Center is a world-renowned nutrition research center.Mission:To promote healthier lives through research and education in nutrition and preventive medicine.The Pennington Center has several research areas, including:Clinical Obesity ResearchExperimental ObesityFunctional FoodsHealth and Performance EnhancementNutrition and Chronic DiseasesNutrition and the BrainDementia, Alzheimer’s and healthy agingDiet, exercise, weight loss and weight loss maintenanceThe research fostered in these areas can have a profound impact on healthy living and on the prevention of common chronic diseases, such as heartdisease, cancer, diabetes, hypertension and osteoporosis.The Division of Education provides education and information to the scientific community and the public about research findings, training programs and research areas, andcoordinates educational events for the public on various health issues.We invite people of all ages and backgrounds to participate in the exciting research studies being conducted at the Pennington Center in Baton Rouge, Louisiana. If youwould like to take part, visit the clinical trials web page at www.pbrc.edu or call (225) 763-3000. PBRC 2012 71