Epidemiology of Obesity EPID 624 – Epidemiology of Chronic Diseases

Presentation Overview Background Attributes associated with obesity Morbidity/mortality Screening Costs Interventions Major research efforts Future research opportunities Discussion/questions

Background Prevalence/Incidence

Defining obesity “Overweight and obesity are defined as abnormal or excessive fat accumulation that may impair health.” - World Health Organization Primary Screening Measure Body Mass Index (BMI) = weight(kg) / height(m) 2

Defining obesity Adults BMI ≥ 30.0 is obese is overweight is normal < 18.5 is underweight Children/Adolescents Sex/age-specific BMI BMI ≥ 95 th percentile is obese 85 th to less than 95 th percentile is overweight

Defining obesity Subdivisions of obesity Grade 1 obesity: BMI Grade 2 obesity: BMI Grade 3 obesity: BMI (extreme obesity) obesity-statistics.aspx#b

Defining obesity AMA debate: Is obesity a disease or a condition/risk factor? “…recognize obesity as a disease state with multiple pathophysiological aspects requiring a range of interventions to advance obesity treatment and prevention.” – American Medical Association National Obesity Awareness Month

Prevalence of obesity globally Adults (18+) 13% obese 600 million 39% overweight 1.9 billion Children (under 5) 6.7% overweight or obese 43 million

Prevalence of obesity in the U.S. Adults (20+) 34.9% obese 78.6 million 70% overweight or obese Children/Adolescents (2-19) 17% obese 12.7 million 33% overweight or obese

interventions_0312.pdf

Prevalence of obesity in the U.S. Past Targets: Healthy People % of adults 5% of children Current Targets: Healthy People % of adults 14.5% of children weight-status/objectives

Incidence of obesity No official measures of U.S. obesity incidence currently Would require accurately identifying the population at risk (non-obese) at a given point in time, as well as new cases Potential for prospective cohort studies to estimate Early Childhood Longitudinal Study, Kindergarten Class of

Attributes associated with obesity Who is most affected?

Race/ethnicity Adults (age-adjusted) 47.8% non-Hispanic black 42.5% Hispanic 32.6% non-Hispanic white 10.8% non-Hispanic Asian Children/Adolescents 22.4% Hispanic 20.2% non-Hispanic black 14.1% non-Hispanic white 8.6% non-Hispanic Asian

Race/ethnicity Higher prevalence for American Indians, Alaska Natives, other Hispanic/Latino, Native Hawaiians, Pacific Islanders vs. non-Hispanic whites Suggestion from WHO Western Pacific Region that BMI cutoffs may need to be lower for some Asian populations due to increased risk for poor health outcomes

Age Adults (20+) 39.5% ages % ages % ages Children/Adolescents 20.5% ages % ages % ages 2-5* *down from 13.9% in less than a decade (2003/2004 – 2011/2012)

statistics/Pages/overweight-obesity-statistics.aspx#b Sex

Genetics Family history of obesity Other conditions, such as Cushing’s disease or polycystic ovary syndrome Potential gene variants affecting hunger or metabolism, interacting with environmental influences

Income Higher incomes associated with decreased risk of obesity in women, but increased risk in non- Hispanic black men and Mexican-American men Being at or below the poverty line is associated with higher rates of obesity among children 9 of 10 states with the highest obesity rates are among the poorest The Weight of the Nation: Part 1 – Consequences (HBO Documentary)

Education Women with college degrees have lower risk of obesity compared to those with less education No educational difference noted for men Generally, obesity rates are lower for children if head of household has college degree versus not finishing high school

Geography & culture Higher prevalence of obesity in rural areas Risk for obesity among immigrants increases with time spent in the U.S. States with highest rates of obesity also have lowest physical activity rates for adults Unhealthy food and physical activity environments Limited food access, availability, affordability

non-hispanic-black.html hispanics.html non-hispanic.html Non-Hispanic Black Adults, Hispanic Adults, Non-Hispanic White Adults,

Adverse behaviors Diets high in calories, added sugars, fast food Average daily calorie intake for adults: 2,234 Low physical activity Only 19% of Americans meet minimum guidelines Television or other media Sedentary activity Increased exposure to food/beverage marketing Over 7.5 hours daily for older children/adolescents

Other risk factors Maternal smoking Extreme birthweight (low or high) Not being breastfed Disabilities Medications (steroids, antidepressants)

Morbidity/mortality Effects on population health

“I would argue that [obesity] is the most significant public health challenge we face at this time, both because of the huge number of people it affects and because of the ripple effects it has and will have on the development of debilitating and costly chronic diseases.” - Daniel R. Glickman, Chair, Institute of Medicine’s Committee on Accelerating Progress in Obesity Prevention,

Morbidity associated with obesity Type 2 Diabetes Cardiovascular Disease Stroke Hypertension Nonalcoholic fatty liver disease Osteoarthritis Some cancers obesity-statistics.aspx#b

Morbidity from childhood obesity Preschoolers who are overweight or obese are 5 times as likely to be overweight or obese as adults Obesity in children associated with high cholesterol and blood sugar, asthma, mental health problems, cardiovascular disease risk factors ~50% of diabetes incidence in adolescence is Type 2 versus 3% a few decades ago Effective obesity treatments can decrease risks

Mortality More deaths globally associated with obesity/overweight than underweight 2.8 million per year ~300,000 deaths each year in the U.S. may be caused by obesity Hard to obtain true estimates without taking age and cohort effects into account Current figures are likely underestimated

Screening Limitations and Recommendations

Body Mass Index BMI was first used in 1835 as a way to estimate the proportion of body fat based on height and weight BMI has low sensitivity, especially below 30 Cannot discern fat vs. muscle content or metabolic risk factors Validity? The Weight of the Nation: Part 1 – Consequences (HBO Documentary)

BMI + waist circumference

Additional limitations Higher BMI associated with more health concerns, though evidence of U or J-shaped relationship with mortality (obesity-mortality paradox) Self-report of height & weight in surveys Potential for measurement error with supplemental measures such as waist circumference or skinfold thickness Reliability?

Revised approaches BMI, plus at least 1 risk factor for other obesity- related diseases, noting that a high waist circumference is considered to be a risk factor Body shape index (ABSI) as potential alternative, taking into account amount/distribution of body fat Subcutaneous (lower risk) vs. visceral (higher risk) Additional measures to account for fitness levels

National survey recommendations Increase capability to consistently measure fitness, endurance, and body composition in children: BMI Waist circumference Skinfold thickness Progressive shuttle run Handgrip strength Standing long jump

Costs Financial impacts on the health care system

Costs of obesity Medical care costs increasing over time due mostly to rise in obesity prevalence Socioeconomic costs also related to disability and premature death Cost estimates are likely too low due to challenges in accounting for conditions related to obesity _0312.pdf

Costs of obesity $147 billion in health care costs in 2008 (10% of all medical spending) Increases in spending from % ($34.3 billion) Medicare 11.8% ($27.6 billion) Medicaid 12.9% ($74.6 billion) Commercial insurance _0312.pdf

Costs of obesity Increases in spending from % ($ 63.9 billion) pharmaceutical services 10.3% ($ 44.7 billion) inpatient services 5.9% ($ 45.2 billion) non-inpatient services _0312.pdf

Costs of obesity Total economic costs for U.S. & Canada, including medical costs, excess mortality and disability: $220 billion/year for obesity $ 80 billion/year for overweight $300 billion/year (~90% from U.S.) _0312.pdf

Interventions Primary, secondary, tertiary, community-level

Primary prevention Preventing obesity before it occurs Regulating caloric energy balance to prevent problematic weight gain Diet Physical activity Environmental factors

Address barriers to a healthy diet Access to healthy food Food advertising Large portion sizes Affordability of healthy food Time constraints Established behaviors

Define “healthy” food Generally low in calories, sugars, fats, sodium Suggestions that nutritional advice is not based on scientific evidence & conclusions of many nutritional studies are problematic/conflicting Changes may be needed to U.S. dietary guidelines to improve health outcomes related to food consumption patterns, such as reducing refined carbohydrates vs. beneficial fats Little change to recommendations in 35 years

Address barriers to physical activity Zoning Safety Areas conducive to physical activity Time constraints Established behaviors

Physical activity guidelines 2.5 hours per week for adults 1 hour per day for children/adolescents Physical activity tends to decline as children get older Estimate 191,000 to 300,000 preventable deaths each year due to not meeting recommendations

Policy options Tax unhealthy foods/beverages 20% or more for population level results Disproportionately burden low income/food access? Subsidize healthy foods to increase affordability Calorie labeling in food service facilities Nutritional literacy, alternate approaches Food purchasing standards for hospitals/schools

Potential effects DataGraphic pdf

Potential roadblocks Role of government versus individual choice Strategies for increasing likelihood of success Stress responsibility to improve unhealthy status quo Work towards political middle-ground Emphasize health and financial benefits Raise awareness of role of individual advocacy Link societal norms to individual risks

Other related approaches The Framingham Heart Study found that obesity was influenced by social networks Potential to use these types of connections to work towards preventing/reversing obesity as well Recommend targeted/tailored prevention approaches might be more effective for children at high risk for obesity and cardiovascular disease

Secondary prevention Recognize overweight or obese individuals early through screening in order to improve outcomes Weight loss interventions Challenges with sustaining weight loss over time Reduce risk factors associated with obesity Secondary screening for potential comorbidities Need to understand different causes and responses to obesity in order to better target treatments

Tertiary prevention Management of severe obesity to reduce complications Bariatric surgery Type 2 diabetes, other comorbidities Medications, if shown to be effective Glucagon-like peptide-1 mimetics (liraglutide) Orlistat

Community-level interventions Incentives for markets to locate to areas with limited food access Food and physical activity standards for childcare, schools, and hospitals Identifying viable/safe resources for promoting physical activity Partnerships for change, including healthy choices and behaviors

Community-level interventions CDC Common Community Measures for Obesity Prevention Project Availability/price of healthy foods/drinks Healthy consumption choices Breastfeeding More physical activity, less inactivity in children Safety to promote physical activity Organized change efforts

Community-level interventions Obesity Prevention Foundation Educational interventions in schools Focus on healthy diet/physical activity choices

Major research efforts Population focus

World Health Organization Commission on Ending Childhood Obesity Promote healthy foods & physical activity Early childhood School age Preconception/pregnancy care Weight management

National Institutes of Health Strategic Plan for NIH Obesity Research Biological processes Risk factors and consequences Sustainable weight loss interventions Population-specific preventions/treatments Improvements in technology Translating research into practice Summary_2011.pdf

Bogalusa Heart Study Bogalusa, LA, ,000 individuals Bi-annual follow-up Key findings Heart disease starts in childhood Obesity associated with insulin resistance/diabetes and hypertension Obese children more likely to become obese adults versus normal-weight peers The Weight of the Nation: Part 1 – Consequences (HBO Documentary)

Robert Wood Johnson Foundation Healthy Eating Research Food/beverages (including access, pricing, marketing, menu labeling, message framing) Child care/school environments Nutrition & agriculture policy Salud America! Targeting childhood obesity in Latino population Food/beverages (including access, marketing) Physical activity

Future research efforts Filling in gaps, expanding on existing knowledge

Key areas of focus Institute of Medicine Food/beverages, including marketing Health care, workplace, schools Physical activity Healthy People 2020 Food access, insecurity, consumption Health care and workplace policies Weight status status/objectives

Intervention guidelines Consistent approaches to initial assessments Ongoing surveillance Monitoring factors associated with changes Evaluating intervention effectiveness

L.E.A.D. Framework

System-wide approaches “Fifty years ago, children did not avoid obesity by making healthy choices; they simply lived in an environment that provided fewer calories and included more physical activity for all. Until a healthier ‘eat less, move more’ environment is created for today’s children, lifestyle interventions like that in the TODAY study will fail.” - David B. Allen, M.D.

Discussion Ideas for research going forward?

Questions?