What is obesity?
complex, multifactorial, chronic disease
interaction of genotype & environment
excessive accumulation of fat
What is the body mass index?
accepted measure of overweight & obesity in children & adults
BMI=Weight/Height
How is the term morbidly obese typically used? What does it really mean? Should we use this term?
extremely obese
- *really means: obese w/ obesity-related comorbidities
- *shouldn’t use the term b/c it is pejorative
What BMI classifies as underweight?
<18.5
What is a normal BMI range?
18.5-24.9
What BMI range is considered overweight?
25-29.9
What BMI range is considered Obese I? Obese II? Obese III?
Obese I: 30-34.9
Obese II: 35-39.9
Obese III: >40
What are the good things about using BMI to classify obesity?
It is low cost & easy.
It correlates well with body fat.
It predicts health risk well.
It is a useful screening tool.
What are the drawbacks of using BMI?
Old people: for a given BMI may have more fat.
Short People (less than 5’): aren’t as overweight as their BMI may indicate
Well-muscled people: aren’t as overweight as their BMI may indicate
Women: for a given BMI may have more fat.
Asians need a different BMI.
What is considered overweight & obese with the BMI for the asian & south asian population?
Overweight: 23-24.9
Obese: >25
Describe how you measure the waist circumference.
tape measure in horizontal plane @ the level of the iliac crest.
Snug, but not compressing the skin
If you have a BMI 25-34.9 & a waist circumference greater than ____ for men & ____ for women…you have a greater risk for what?
>102 cm or 40 inches for men. >88 cm or 35 inches for women Greater risk for: HTN Type II Diabetes Dyslipidemia coronary heart disease
How do you define metabolic syndrome?
3/5 risk factors Abdominal obesity High fasting glucose High triglycerides High cholesterol High Blood pressure
How do you define obesity for children & adolescents? What are these ranges?
BMI in percentiles
Works for ages 2-20
Underweight: 95th percentile
Severe Obesity: >99th percentile
The US Preventative Services Task Force recommends intensive counseling for obese adults. What qualifies as intensive counseling?
more than 1 session per month for at least 3 months
T/F Overweight and obese individuals were 40% and 42% less likely in 2008 compared with 1994 to self-diagnose as overweight.
True.
Between 1994 & 2008 there was an ___ percentage increase in the prevalence of being overweight. How did this change the odds of being diagnosed as overweight by a physician?
69% increase in the prevalence
no change in the odds
What percentage of obese patients are diagnosed?
20%
How does the US rank in terms of obesity?
ninth most obese country
What fraction of the US adults are obese? Overweight? Normal weight?
1/3 obese
1/3 overweight
1/3 normal weight
There is a greater prevalence in obesity in which of these groups? Black men/White men Black women/White women Hispanic men/White men Hispanic women/White women
White men>Black men
Black women>White women
Hispanic men>White men
Hispanic women >White women
Childhood obesity is most common in which 3 ethnic groups?
American Indians
Non-hispanic blacks
Mexican Americans
Having an obese parent increases your risk for obesity by what factor?
2-3 fold
T/F Obesity is more prevalent in low income populations.
True.
What 3 things predict whether childhood obesity will persist into adulthood?
Age: the older you are when you are obese…the more likely to stay that way
Parental Obesity
Severity of Obesity: the more severe…the more likely to stay obese
How can we describe the interaction of genes & environment in determining obesity?
Genes load the gun.
Environment/Behavior pulls the trigger.
What are the 3 general categories of obesity genetics?
- Monogenic forms of obesity
- Syndromic forms of obesity
- Common obesity
What are monogenic forms of obesity?
What percentage of people have this?
What effects does this have?
rare forms of obesity that are caused by a spontaneous mutation in a single gene (6 known)
occurs in 5-10% of the severely obese
affects appetite control, food intake, energy homeostasis
codes for leptin, leptin receptor, pro-opiomelanocortin, melanocortin-4-receptor
Describe what happens with leptin deficiency.
leptin deficiency is inherited in an aut recessive manner…produces extreme, early-onset obesity with intense hyperphagia
hypogonadotrophic hypogonadism w/ spontaneous puberty
**can be fixed w/ leptin treatments
What is hyperphagia?
abnormally increased appetite, usu b/c of an issue w/ the hypothalamus
Describe what happens with human leptin receptor deficiency.
aut recessive extreme obesity hyperphagia delayed puberty normal basal temp & resting metabolic rate **different than leptin deficiency: mild growth retardation impaired Growth hormone secretion hypothalamic hypothyroidism
Describe what happens with melanocortin 4 receptor deficiency.
inherited co dominant manner
early onset hyperphagia, increased fat mass, lean mass, bone density, linear growth & hyperinsulinemia
Responsible for 1-6% of severe cases of obesity
What is the most common monogenic form of obesity?
melanocortin 4 receptor deficiency
What is syndromic obesity?
obesity caused by a syndrome
often accompanied by mental retardation, reproductive issues, other health problems
25 types known
What is the most common form of syndromic obesity?
Prader Willi Syndrome
due to genomic imprinting (matters which parent you inherit it from)
What are the symptoms of PW?
hyptonia poor feeding @ infancy extreme hyperphagia later & central obesity at 3-8 years of age hypogonadism short stature (not enough GH) behavioral problems cognitive issues
What is Bardet-Biedl Syndrome?
can be caused by 15 different genes-->similar presentation w/ all obesity microorchidism in men mental retardation retinal dystrophy-->blindness polydactyly renal issues
What does the twin study suggest about common obesity?
Monozygotic twins have a much higher correlation for obesity than dizygotic twins.
This suggests that genetics plays a factor. Hard to identify the genes that factor in tho…environment is a huge deal!!
T/F Portion size affects consumption!
TRUE.
this is simply true. studies show that a bigger plate of food–>even if you don’t eat it all–>you’ll eat more.
T/F You should drink your calories as you will become fuller faster.
FALSE
people who drank their calories in one study ended up consuming more calories that day b/c it didn’t satisfy their appetite.
T/F Being obese reduces your life expectancy.
True.
T/F Having metabolic syndrome reduces your life expectancy.
True.
Focusing on the head…what are some health implications of obesity?
cataracts
idiopathic intracranial hypertension
stroke
What are some pulmonary complications of obesity?
abnormal fcn
sleep apnea
hypoventilation syndrome
What are some liver complications of obesity?
nonalcoholic fatty liver disease
steatosis
steatohepatitis
cirrhosis
What are some gynecological complications of obesity?
abnormal menses
infertility
polycystic ovarian syndrome
What is the effect of obesity on risk of cancer?
increase in risk of breast, uteris, cervix, colon, esophagus, pancreas, kidney, prostate cancer
What are some complications of obesity that can be seen in your extremities?
phlebitis venous stasis skin issues gout osteoarthritis
What are some other complications of obesity?
coronary heart disease Type II Diabetes Dyslipidemia HTN Severe pancreatitis Gall bladder disease
What percentage of Type II Diabetes cases is attributable to excess weight?
90% of the cases!!
What percentage of cases of HTN could be due to excess weight?
For every 1 kg lost…what reduction is seen in systolic & diastolic mmHg?
26-28% of the cases
1kg=1mmHg
What percentage of cancer deaths in men & in women are accounted for by obesity?
Men: 14%
Women: 20%
How common is weight discrimination? What is the number 2 source of stigma?
It is the 4th most common form of discrimination, right up there with race & age.
Health care providers
What are bad terms to use with obese patients?
Bad terms: fatness excess fat obesity large size
What are better terms to use with obese patients?
Better terms: weight heaviness BMI excess weight unhealthy body weight weight problem unhealthy BMI
T/F More healthcare dollars are spent on obesity than smoking.
TRUE
