Chapter 7 (Exam 3)
Healthy BMI range?
18.5-24.9
What changes in the U.S. environment and lifestyle have contributed to the obesity epidemic?
financial burdens of medical costs fewer jobs require physical activity screen time entertainment
Gynoid body shape
(subcutaneous) at the hips and below the waist
Android body shape
(visceral) around abdominal region and above waist
Major limitations of using BMI for classification
Athletes- BMI might be above the healthy body weight range because they have a large amount of lean body mass Pregnancy- rapidly changing weight and body composition
What are the components that make up total energy expenditure?
BMR- basal metabolic rate PA- physical activity TEF- thermic effect of food
What contributes to the most TEE in a sedentary person?
Basal Metabolism
What's the thermic effect of food?
Energy needed to digest, absorb, and process nutrients from foods. fat<CHO<protein
What is EER and what are some of the variables used in its calculation?
Estimated energy requirements Variables: height, weight, age, gender, and PA
Best approach to body weight management
Involves reducing energy intake, increasing activity, and changing behavior to promote weight loss and long term management.
Explain how energy balance is related to body weight.
It simply means that body weight is not changing
What component is most variable between individuals?
Physical Activity
What happens to excess calories when we eat more energy than we expend?
extra energy will be stored as glycogen in the liver and muscle and as fat in adipose tissue
How does the distribution of body fat affect the risks of excess body fat?
Visceral fat (around the organs) increases health risks more than subcutaneous fat (under skin)
When we are in a calorie deficit, how do we meet our energy needs and maintain blood glucose?
body protein is broken down to amino acids to make glucose
Describe what it means to be in energy balance.
consumption and expenditure are equal
Describe what it means to be in positive energy balance.
consumption greater than required amount
Describe what it means to be in negative energy balance
consumption less than required amount
The factors that increase basal metabolic rate
increasing lean body mass greater height and weight raise body temperature
Measuring energy expenditure: Doubly labeled water
ingest isotopes of hydrogen and oxygen
The factors that decrease basal metabolic rate
lower energy diet starvation decrease in age
Measuring energy expenditure: Indirect Calorimetry
measuring oxygen and CO2 production in chamber
Mechanism that makes you want to eat and stop eating
nerves in stomach and small intestine sense pressure and volume of food and send a message to the brain to either start or stop eating.
Role of leptin in controlling body weight
peptide hormone produced by adipocytes that signals information about the amount of body fat `
Measuring energy expenditure: Direct Calorimetry
placement in chamber to measure heat given off
How can you calculate BMI?
weight in kg/(height)^2
How can dietary carbohydrate and protein be stored as fat? Is this preferred to storing dietary fat?
when CHO is converted to pyruvate, amino acids, and NH2; then acetyl CoA can convert them to fatty acids not preferred because dietary fat expends much less energy
