Week 3 Nutrition and Obesity Lecture

Question 1

what two factors primarily contribute to obesity?

Answer 1

genetics and lifestyle (diet, exercise, sleep)

Question 2

what BMI range is overweight?

Answer 2

25-29.9

Question 3

what BMI range is obese?

Answer 3

> 30

Question 4

how do you calculate BMI?(2)

Answer 4

BMI=kg/m^2 OR BMI=(lb x 703)/in^2

Question 5

a high MBI has been correlated to increased risk for which diseases?3

Answer 5

hypertension, cardiovascular disease, sleep apnea…

Question 6

as BMI increases, standard mortality rates__

Answer 6

increase

Question 7

how do you determine waist to hip ratio?

Answer 7

WHR=waist circumference/hip circumference

Question 8

what is a healthy WHR for men? women?

Answer 8

men: 0.9
women: 0.8

Question 9

what is an “at risk” hip ratio?

Answer 9

greater than or equal to 1

Question 10

what has been better correlated to incidence of myocardial infarction, BMI or WHR?

Answer 10

WHR

Question 11

describe the adipocytes of an overweight person?

Answer 11

adipocytes are larger and more numerous

Question 12

describe the adipocytes of a average sized person who was once overweight

Answer 12

adipocytes are smaller but still more numerous. in a person that loses weight, adipocyte size decreases but number stays the same

Question 13

scientists have discovered how many loci involved in mendelian forms of obesity? how may loci are contributing?

Answer 13

9 involved, 58 contributing

Question 14

does a genetic predisposition to obesity mean you will be fat?

Answer 14

no. lifestyle changes can overcome genetics in most cases

Question 15

what is the set-point theory?

Answer 15

your body has a functionally optimal weight range that it tries to maintain by influencing appetite

Question 16

what is satiety?

Answer 16

feeling full

Question 17

Leptin: secreted by, role2? long/short term factor

Answer 17

secreted: adipocytes

stimulates hypothalamus to reduce food intake and increase energy expenditure

long

Question 18

leptin levels are increased/decreased with increased adipose tissue

Answer 18

increased

Question 19

Ghrelin: secreted by? stimulates2? long/short term factor

Answer 19

secreted by stomach when you anticipate a meal

stimulates hypothalamus to release hormones and increase food intake

short

Question 20

PYY: secreted by? role3? short or long term factor?

Answer 20

produced in ileum and colon

suppresses appetite, lowers food intake, slows passage of nutrient through gut

short

Question 21

orexin: produced? role? 3

Answer 21

produced in lateral hypothalamus

increased food consumption, wakefulness and suppresses REM

Question 22

your a fat person, which hormones (PYY, orexin, leptin, ghrelin) are good for weight loss?

Answer 22

leptin and pyy

Question 23

how is sleep related to obesity?

Answer 23

decreased sleep increases the risk of obesity

Question 24

what effect (on hormones) does a lack of sleep have?

Answer 24

decreases leptin, increases ghrelin

Question 25

what are the weekly physcial activity guidelines for americans?

Answer 25

1 hr and 15 min each week of vigourous aerobic activity, 2 hr 30 min of moderate aerobic activity, muscle strenghtening atleast 2 x a week

Question 26

exercise does not burn that many calories, so why is it so effective in weight loss?

Answer 26

lean body mass (built by exercise) increases basal metabolic rate which burns more calories than physical activity

Question 27

why do our bodies not require carbs?

Answer 27

glucose and glycogen can be made from gluconeogenic sources

Question 28

what was the atkins diet? did it work?

Answer 28

low carb, high protein, high fat diet. It worked in the short-term becuase our bodies were breaking down fats to make energy, but it was not helpful in sustained weight loss and actually led to some health issues correlated with high fat intake

Question 29

why is high fructose corn syrup bad?

Answer 29

fructose bypasses normal regulatory mechanisms of glucose and is readily converted to excess fat. fructose is also more effieciently metabolized by the liver so less escapes into blood.

Question 30

increased red meat has been correlated with…

Answer 30

some types of cancers

Question 31

increased carbohydrates intake (except for simple carbs and high levels of added sugars) have been correlated with…

Answer 31

decreased obesity. abundance of simple carbs and high levels of added sugars increases obesity