Obesity Flashcards
What Factors Contribute to the development of obesity?
- G______/E_______
- B_______ (inactivity)
- En_______
- Ps_______ (binge eating disorders)
- M_______ ( insulin, steroids)
- E_______ factors
- M_______ conditions
- Genetics/Epigenetics
- Behavioral
- Endocrine
- Psychological
- Medications
- Environmental
- Medical Conditions
What factors (in terms of gender, race/ethnicity, education, geographic region) are associated with a greater rise in obesity in the years leading up to 2016?
No biological difference, race and ethnic differences reflect social and cultural issues
What conditions are among some of the most common obesity-related complications?
- D_______
- C______
- Ost______
- Nonalcoholic (1)
- _ _ _
- Diabetes Type 2
- Cancer
- Osteoarthritis
- Nonalcoholic fatty liver disease
- OSA
What is BMI? How is it Calculated?
Obesity = BMI of?
Body Mass Index = weight (kg)/height (meters2)
Used to screen for obesity and categorize pts risk for obesity related disorders
BMI > 30
Advantages and Disadvantages of using BMI to assess obesity risk?
Advantages
- High correlation to?
- Minimal _____
- In______
- Non_______
Limitations
- Surrogate measure so can result in (2)
- Ignores ______ variability
- % total body fat
- Minimal time
- Inexpensive
- Noninvasive
- Overestimation (high lvls of muscle), Underestimation (low lvls of muscle)
- ethnic variability (certain ethnic groups have increased risk of weight related comorbidities at lower BMI’s than caucasians -> need to use adjusted BMI cutoffs)
What type of body fat distribution is associated with the highest risk for metabolic disease? How can this be assessed in a non-invasive way?
- Subcutaneous fat tends to be metabolically benign
- Excess visceral fat = directly tied to increased risk of type II DM, HTN, Cardiovascular disease, metabolic diseases
- Waist circumference is indirect way to assess amount of visceral fat (especially waist:hip ratio around hip mostly subcutaneous fat)
How did the intermittent and unreliable access to food in early human history shape the general direction of our system for maintaining energy balance and energy stores?
- Food was scarce with moments of starvation. In order to survive, we developed an internal alert system. Human genes have evolved into the development of a complex appetite and energy regulated system…
- Storing fat as energy for later
- We’ve developed ways to keep food nearby from animal domestication, preserving foods (canned food),
What brain regions control appetite and energy expenditure? These brain regions depend on signals from which body structures to modulate appetite and energy expenditure?
The control centers in the brain (prefrontal cortex/ cortex/ hypothalamus/ amygdala/ nucleus accumbens/ brainstem) send signals to and from peripheral organs (adipose tissue and gut)
Which brain regions involved in controlling appetite and energy expenditure are also involved in our pleasure/reward system? What neurotransmitter is critical for our reward system?
- Amygdala/ nucleaus accumbens/ hypothalamus are the reward system
- Explains why highly palpable foods are able to override homeostatic signals which would normally tell us to end a meal
- DOPAMINE- is the neurotransmitter for desire….dopamine reminds you of a past pleasure ex: food, sex, etc. Related to emotional eating.
What is the hypothesized connection between the number of dopamine receptors, intensity of the pleasure/reward response, tendency for overeating, and risk for obesity?
- Some patients with obesity have less dopamine in dorsal striatum than lean counterparts
- Taq1A regulatory gene is associated with increased likelihood of obesity
- Those who lack this gene have a normal amount of dopamine receptors and STOP eating
- Those who have this gene have less dopamine receptors and continue eating to compensate for hypofunctioning dopamine reward system
What hormonal changes associated with insufficient sleep can cause increased appetite and increased risk for obesity?
What is an Obesogenic Environment? What aspects of modern life and society contribute or promote this kind of environment?
- Obesogenic Environment: environmental changes that promote behaviors which favor weight gain
- Decreased energy expenditure
- More sedentary occupations due to decreased automation
- Workplace layout discourages physical activity
- Home appliances
- Play time for children has been shortened
- Increased sedentary time watching tv, video games etc
- Dangerous neighborhoods
- Increased energy intake
- Increased availability and advertising of calorie dense foods
- Increased snacking
- Consumption of sugar sweetened beverages.
- Increased portion sizes
- Decreased sleep time
- Food insecurity- cheaper calorie dense foods, overeating when food is available.
- Mindless distracted eating- we get distracted from sensory input
- Food insecurity - cheaper, calorie dense foods, or overeating when more food available
What is a “Food Desert”? Who is most likely to be affected by these kinds of locations?
- *Contributes to higher rates of obesity in impoverished areas
- Effects elderly or fixed/low income individuals
Based on the many factors that contribute to obesity, what are some key components that can/should be included in a personalized treatment plan?
What type of screenings and specialists may be needed for a personalized treatment plan to be effective?
A variety of genes have been found to directly affect 7 parameters related to weight and adiposity. Identify and define those 7 parameters.
- B_____weight
- _____ to _____ ratio or waist c______ adjusted for ____
- V_______ adiposity
- _____ to _____ ratio or _____ circumference
- Extreme ob_____
- B _ _ relatd
- Body F___
- ______ centers around a group of genes
- (1) genes affect 4/7 parameters. Highly related to _____
- Birthweight
- Waist to hip ratio, waist circumference adjusted for BMI
- Visceral adiposity
- Waist to hip ratio or waist circumference
- Extreme obesity
- BMI related
- Body Fat
- Overlapping
- FTO genes, high regulated BMI
Explain the findings of the 1990 and 1994 study comparing weight gain and loss among monozygotic twins. What do these findings suggest about the strength of the factors that influence the response an individual’s body may have to overeating or dieting?
- Both positive energy balance (overfeeding) and negative energy balance (increased exercise) causes_______ changes in body weight
- Twin A gained 7kg and twin B gained 8kg, Second graph twin A lost 8 and twin B lost 7.5kg
- Demonstrates a body’s response to energy intake is from _______ and not just _______
- Bc twins ______ genes they react ______ to under or overeating HOWEVER different twin pairs react _______
- Diff ppl’s bodies respond diff to diff _________ - similar genes, diff env________ (ex Pima ______)
- similar
- GENETICS not just BEHAVIOR
- twins share genes they react similarly, diff twin pairs react differently
- environments - diff genes, diff environments (Pima indians)
- GENETICS not just BEHAVIOR
What is Epigenetics?
How does epigenetics help explain how environment can affect gene expression?
What environmental factors are known to cause epigenetic changes?
Epigenetics = environment can change gene expression without changing genetic code. Can be passed down to offspring
Ex) Addition of methyl group, preventing binding of transcription factors, presenting expression.
- Effects if histone tail is exposed vs. nonexposed (accessible)
Epigenetic changes can increase risk of obesity for multiple generations
For babies born “small for gestational age” SGA, it is believed that they experience malnutrition-induced-epigenetic changes in utero that increase the expression of metabolic-efficiency genes (i.e. able to more easily store fat from fewer calories and better at conserving energy.) What observed differences among 10 year olds born SGA vs. AGA lead to this SGA-metabolic-efficiency theory?
- AT 4 years, children born LGA are born with larger and average for gestational age, the LGA are born with higher BMIs
- At 10 years, Found females and males born SMALLER than GA, are also found to be obese. Adapt to an intrauterine environment where there was little nutrition, so their body learns to hold onto calories.
- Also high caloric intake for catch up growth
What trend did studies find between percentage of visceral fat and birth weight? How is this trend similar with adult onset diabetes?
Smaller and larger weight are born with more visceral fat.
Also higher for DM for smaller and larger GA vs normal GA.
True or False – intensive weight loss interventions (compared to no intervention), while successful in the short term, do not result in long term improvement of health due to a high rate of weight regain. Explain your answer.
False: although weight did increase in years 1-5, in 10 yrs, despite weight regain, 6% weight loss still enough to maintain improvement in cardiovascular risk factors
What percentage, on average, of those losing 10% or more of their body weight managed to maintain the loss for at least 2 years?
Most optomistic data suggest that 60% of those cannot maintain 10% weight loss for more than 2 years -> Answer is ~40%
However statistic is inaccurate bc data only from ppl in commercial weight loss programs
Describe the following hormones with regard to their site of production and actions in the body
-
Ghrelin
- Source =
- Normal Function =
- Alteration =
-
Peptide YY
- Source =
- Normal Function =
- Alteration =
- Gastric fundus
- Stimulate appetite, particularly high fat, high sugar foods
- Levels increase during dieting and weight loss
- Distal small intestine
- Suppresses appetite
- Levels decreased in obese persons
What drugs/drug classes are associated with weight gain?
Among those whose weight loss was tracked by the National Weight Loss Registry, what percentage of individuals used both diet and exercise to lose weight? What behaviors were associated with successful maintenance of weight loss.
- 89% used?
- Behaviors
- Following a (1) diet 1400-1800kcal/day
- 60-90 min (1)
- Daily _______
- Self _______ weight
- Action _____ if weight increases a few pounds
- both diet and physical activity
- low calorie diet
- moderate physical activity
- daily breakfast
- self monitor
- plan
Which medications are approved by the FDA for long-term therapy for weight loss? What percentage of weight loss is associated with these medications?
(LLNPO)
On average, weight loss achieved on these medications is 10%, however some may not be candidates for or respond to some meds
How does the average weight loss success rate of bariatric surgery compare to that of anti-obesity medications or life style modification alone? What is the likely explanation for the difference?
- 15-35% weight loss at 5 yrs
- However this means that after 5 years, many ppl will gain the weight back -> so need surgery + lifestyle modification combination to keep it off
- All mechanisms are not known but probably due to anatomic and hormonal changes and not from sheer will pair
- However is not a magic bullet and weight regain does occur although at a much lower rate than with lifestyle or medication interventions.
