Obesity in the United States Amber Marchus

Outline What is obesity? – How it is measured Obesity Related Health Risks Increasing obesity trends – Worldwide – Within the United States – Obesity in Hispanics Causes Prevention/Treatment

What is Obesity?

Measurements of Obesity Body Mass Index (BMI) Underwater weighing Bioelectrical impedance Dual-energy X-ray absorptiometry (DEXA) Skin-fold measurements

Body Mass Index Body mass index: weight in kg divided by height in meters squared – My BMI=22.5 – High correlation with body fatness-not a direct measure Most accurate measure – Easy – Low cost – Immediate Results

BMI Criticisms Health risks can be more correlated with waist circumference than BMI alone – Abdominal fat is a predictor of risk for obesity related diseases, particularly in men High BMI: athletes (muscle), sex (women vs. men) Low BMI: at risk (high body fat %)

Measurements of Obesity Underwater weighing – Determines body composition: body fat to lean mass – Lean mass denser than water (sinks) & fat mass less dense (floats) – Individual with more fat will float Bioelectrical impedance – Electric current flows at different rates through body depending on composition – Body made up of water with ions (current flows) and fat (resistant to current) DEXA – Can directly measure fat, lean tissue, and bone mass – Relies on x-rays to generate different energies; degree of difference used for calculation Skin-fold thickness measurements – Estimate body fat percentage by measuring thickness of skin at certain places on body – Pulls skin away from muscle so calipers are holding only skin and fat, measured in millimeters, used for calculation

Why is BMI used? Other methods are: – Expensive – Machinery – Availability – Trained professionals to take correct measurements – Difficult to standardize across observers

Obesity Related Health Risks

World Wide Obesity Trends

Increasing Obesity Trends

BMI Trends among US men & women. National Health and Nutrition Examination Survey

Obesity Then: 1970’s Obesity Now: % among 2-5 year olds10% among 2-5 year olds 4% among 6-11 year olds20% among 6-11 year olds 6% among year olds18% among year olds

Obesity in Hispanics

Causes Genetics – Leptin – Ghrelin – Insulin Lifestyle

Genetics Leptin – Peptide expressed by fat cells that regulates fat metabolism and energy intake – “I’m full” signal – Levels rise after a meal and are low before Ghrelin – Peptide expressed by cells lining the stomach and pancreas – “I’m hungry” signal – Levels rise before a meal and fall after a meal Insulin – Hormone produced by the pancreas that causes uptake of glucose from the blood to be stored as glycogen – Resistance has correlation with obesity, failure to regulate blood glucose levels can lead to Type II Diabetes

Lifestyle Diet – High in refined sugar and fats: promote weight gain – Recommended macronutrient consumption: 45-65% from carbohydrates, 10-35% from proteins, and % from fats Our culture has become accustomed to the problem so we don’t recognize it when we see it, if an individual is heavier than us, we think that we are okay – ayer_embedded ayer_embedded

Lifestyle Ease and cost of unhealthy foods – Daily caloric intake for men should be around 2500 calories and 2000 for women (depends on age, height, physical activity level, current weight) – Cheeseburger 300, large fry 500, large soda 310 – Total 1110! Physical Activity – Children and adolescents (6-17 yrs.) should do 60+ min. of physical activity daily – Adults (18-64) should do at least 150 min. a week of moderate intensity, or 75 min. a week of vigorous-intensity physical activity – Older adults (65+) should follow the adult guidelines. If they can’t meet guidelines, they should be as physically active as their abilities and conditions will allow

Prevention Prevention of weight gain (education) Promotion of weight maintenance (exercise) Management of obesity co-morbidities (treat health issues) Promotion of weight loss Preventing obesity is more effective than treating the acquired condition – Cost to the individual as well as society

Treatments in Severe Cases Gastric bypass – reduces the size of the stomach Sleeve gastrectomy – 85% of the stomach is reduced Lap-band system – Band wrapped around the upper portion of the stomach to create a small pouch and confine stomach volume Restrict stomach size to reduce amount of calories taken in

1 pound of fat=3500 calories

Sources About BMI for Adults. Centers for Disease Control and Prevention. 13 September Martinez-Hernandez, Alfredo, et al. “Genetics of Obesity.” Public Health Nutrition. 10 (2007) Nichaman, Milton Z, and Gloria Garcia. “Obesity in Hispanic Americans.” Diabetes Care. 14 (1991) Wang, Youfa and May A. Beydoun. “The Obesity Epidemic in the United States-Gender, Age, Socioeconomic, Racial/Ethnic, and Geographic Characteristics: A Systematic Review and Meta- Regression Analysis.” Epidemiologic Reviews. 29 (2007) Kopelman, P. “Health risks associated with overweight and obesity.” Obesity Reviews. 8 (2007) Popkin, Barry M, and Colleen M. Doak. “The Obesity Epidemic is a Worldwide Phenomenon.” Nutrition Reviews. 56 (1998)

Education Level Of Education Percentage of Obesity