Flashcards in Obesity & Starvation (Maris) Deck (40):
The energy expended by our bodies in order to consume and process food is known as what?
What is the largest component of energy expenditure? What is the smallest?
Basal metabolism; thermic effect of food
What is basal metabolism?
Energy expenditure to do everything you need to do to be alive in a resting state; 2/3 energy expenditure.
Which organs/tissues contribute most to energy expenditure?
Brain, liver, muscles
What is the basal metabolic rate?
Rate at which energy is expended on basic life activities.
What are the 5 influences of/on hunger, satiation, and satiety?
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
According to the CDC, what is the greatest harm to collective health in the US?
Do substantial differences exist in obesity prevalence by race/ethnicity? Do they vary by age and sex if yes?
Yes to both
In the US, what percentage of calories are actually consumed as plant food?
In the US, what percentage of calories are actually consumed as animal food?
In the US, what percentage of calories are actually consumed as processed food?
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?
Poor nutrition, low levels of physical activity
What is "Let's Move"?
A program developed by First Lady Michelle Obama to solve the epidemic of childhood obesity within a generation.
How are excess calories stored?
In terms of body fat and its distribution, what matters most in terms of disease risk?
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.
What is the difference between white and brown fat?
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.
Where is brown fat located on infants? What is the percentage of total body mass that it takes up?
Upper spine & shoulders for warmth; 5% total body mass.
Do adults have brown fat?
Yes - small reserves in shoulders and neck.
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?
Ebf2 (early B cell factor 2), BMP signaling, deacetylase SirT1
What does LPL (lipoprotein lipase) do?
Removes triglycerides from the bloodstream for storage in adipose tissue and muscle cells.
Where is LPL activity high in women? ?
Women - breasts, hips, thighs. Men - abdomen.
What have studies shown regarding LPL activity in obese people?
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.
What happens to LPL activity after weight loss?
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.
What are some causes of obesity?
Genetics/epigenetics, environmental, cultural, behavioral, socioeconomic, phsychological, etc...Often involves the interaction of many factors, making it difficult to address.
Give an example of a genetic/epigenetic cause of obesity that we've talked about in several classes already.
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.
Explain Leptin and what happens when people have mutations in the Leptin gene or the gene encoding its receptor.
Leptin signals sufficient energy stores and suppresses appetite. People with these mutations have insatiable appetites and become obese.
Where in the world is the number of undernourished people decreasing? Where is it increasing?
Decreasing - Asia, the Pacific. Latin America, Caribbean. Increasing - Africa, developed regions.
What is the principal cause of hunger?
What is food insecurity?
Limited or uncertain availability of nutritionally adequate and safe foods.
What is a food desert?
No car and no supermarket store within one mile.
What is the poverty-obesity paradox?
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.
Compare fasting and starvation.
Fasting - when people choose not to eat. Starvation - when people have no choice not to eat.
What happens to the body during fasting?
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.
What is BUN and how does it relate to fasting?
BUN = blood urea nitrogen. Urea nitrogen is what forms when protein breaks down. You'll see elevated BUN when fasting.
Why do you get a reduced resistance to disease with starvation?
Body doesn't have enough antibodies because they've broken down, along with other proteins in the body, to supply needed energy.
What is an eating disorder?
Disturbances in eating behavior that jeopardize a person's physical or psychological health.
What is disordered eating?
Eating behaviors that are neither normal or healthy, including restrained eating, fasting, binge eating, and purging.
What is anorexia nervosa?
Eating disorder characterized by a refusal to maintain minimally normal body weight and a distortion in perception of body shape and weight.
What is bulimia nervosa?
Eating disorder characterized by repeated episodes of binge eating usually followed by self-induced vomiting, misuse of laxatives or diuretics, fasting, or excessive exercise.