Obesity & Starvation (Maris)

Question 1

The energy expended by our bodies in order to consume and process food is known as what?

Answer 1

Thermic effect

Question 2

What is the largest component of energy expenditure? What is the smallest?

Answer 2

Basal metabolism; thermic effect of food

Question 3

What is basal metabolism?

Answer 3

Energy expenditure to do everything you need to do to be alive in a resting state; 2/3 energy expenditure.

Question 4

Which organs/tissues contribute most to energy expenditure?

Answer 4

Brain, liver, muscles

Question 5

What is the basal metabolic rate?

Answer 5

Rate at which energy is expended on basic life activities.

Question 6

What are the 5 influences of/on hunger, satiation, and satiety?

Answer 6

1. Physiological - hunger
2. Sensory - seek food and start meal
3. Cognitive - keep eating
4. Postingestive - satiation: end meal
5. Postabsorptive - Satiety: several hours later

Question 7

According to the CDC, what is the greatest harm to collective health in the US?

Answer 7

Obesity

Question 8

Do substantial differences exist in obesity prevalence by race/ethnicity? Do they vary by age and sex if yes?

Answer 8

Yes to both

Question 9

In the US, what percentage of calories are actually consumed as plant food?

Answer 9

12%

Question 10

In the US, what percentage of calories are actually consumed as animal food?

Answer 10

25%

Question 11

In the US, what percentage of calories are actually consumed as processed food?

Answer 11

63%

Question 12

What are some leading contributors to some of the urgent health challenges facing the US, such as obesity, high blood pressure, heart disease, cancer, and diabetes?

Answer 12

Poor nutrition, low levels of physical activity

Question 13

What is “Let’s Move”?

Answer 13

A program developed by First Lady Michelle Obama to solve the epidemic of childhood obesity within a generation.

Question 14

How are excess calories stored?

Answer 14

As fat

Question 15

In terms of body fat and its distribution, what matters most in terms of disease risk?

Answer 15

Distribution of fat appears to be more critical than total amount of fat. Visceral upper-body fat stored around abdominal organs is associated with high risk for many diseases.

Question 16

What is the difference between white and brown fat?

Answer 16

White fat stores energy as large fat droplets. Brown fat has much smaller droplets and is specialized to burn them, yielding heat. Brown cells look brown because they’re packed with mitochondria.

Question 17

Where is brown fat located on infants? What is the percentage of total body mass that it takes up?

Answer 17

Upper spine & shoulders for warmth; 5% total body mass.

Question 18

Do adults have brown fat?

Answer 18

Yes - small reserves in shoulders and neck.

Question 19

There’s a lot of interest in seeing if we can “brown” white fat since it can burn more calories and protect overfed mice from obesity. What do 3 recent mouse studies of these effects look at to determine if this browning can be accomplished?

Answer 19

Ebf2 (early B cell factor 2), BMP signaling, deacetylase SirT1

Question 20

What does LPL (lipoprotein lipase) do?

Answer 20

Removes triglycerides from the bloodstream for storage in adipose tissue and muscle cells.

Question 21

Where is LPL activity high in women? ?

Answer 21

Women - breasts, hips, thighs. Men - abdomen.

Question 22

What have studies shown regarding LPL activity in obese people?

Answer 22

That they have more LPL activity in their adipose tissue. High LPL activity leads to efficient storage. There’s something about increasing caloric uptake that makes the enzyme much more active and efficient at storing fat.

Question 23

What happens to LPL activity after weight loss?

Answer 23

It increases. This is why most people regain weight after having lost it. Enzymes want to store fat. This is why it’s important to prevent obesity in the first place.

Question 24

What are some causes of obesity?

Answer 24

Genetics/epigenetics, environmental, cultural, behavioral, socioeconomic, phsychological, etc…Often involves the interaction of many factors, making it difficult to address.

Question 25

Give an example of a genetic/epigenetic cause of obesity that we’ve talked about in several classes already.

Answer 25

Prader Willi Syndrome - example of maternal imprinting; deletion of region from paternal chromosome or maternal uniparental disomy results in this. Insatiable appetite, which leads to chronic overeating and obesity.

Question 26

Explain Leptin and what happens when people have mutations in the Leptin gene or the gene encoding its receptor.

Answer 26

Leptin signals sufficient energy stores and suppresses appetite. People with these mutations have insatiable appetites and become obese.

Question 27

Where in the world is the number of undernourished people decreasing? Where is it increasing?

Answer 27

Decreasing - Asia, the Pacific. Latin America, Caribbean. Increasing - Africa, developed regions.

Question 28

What is the principal cause of hunger?

Answer 28

Poverty

Question 29

What is food insecurity?

Answer 29

Limited or uncertain availability of nutritionally adequate and safe foods.

Question 30

What is a food desert?

Answer 30

No car and no supermarket store within one mile.

Question 31

What is the poverty-obesity paradox?

Answer 31

The highest rates of obesity occur among those living in the greatest poverty; many healthful food choices are not readily available in low-income neighborhoods, and nutrient-rich foods cost more than calorie-dense foods.

Question 32

Compare fasting and starvation.

Answer 32

Fasting - when people choose not to eat. Starvation - when people have no choice not to eat.

Question 33

What happens to the body during fasting?

Answer 33

Liver’s glycogen stores are used and you get a shift to ketosis - fatty acids from adipose tissue enter cells and are broken down to yield acetyl CoA to deliver energy.

Question 34

What is BUN and how does it relate to fasting?

Answer 34

BUN = blood urea nitrogen. Urea nitrogen is what forms when protein breaks down. You’ll see elevated BUN when fasting.

Question 35

Why do you get a reduced resistance to disease with starvation?

Answer 35

Body doesn’t have enough antibodies because they’ve broken down, along with other proteins in the body, to supply needed energy.

Question 36

What is an eating disorder?

Answer 36

Disturbances in eating behavior that jeopardize a person’s physical or psychological health.

Question 37

What is disordered eating?

Answer 37

Eating behaviors that are neither normal or healthy, including restrained eating, fasting, binge eating, and purging.

Question 38

What is anorexia nervosa?

Answer 38

Eating disorder characterized by a refusal to maintain minimally normal body weight and a distortion in perception of body shape and weight.

Question 39

What is bulimia nervosa?

Answer 39

Eating disorder characterized by repeated episodes of binge eating usually followed by self-induced vomiting, misuse of laxatives or diuretics, fasting, or excessive exercise.

Question 40

How do tips for combating eating disorders for athletes and dancers differ from those given to others?

Answer 40

Use performance-based goals, restrict weight-loss activities to off-season, and focus on proper nutrition as an important aspect of training and technique.