Chapter 10: Energy Balance Flashcards
define: energy
the ability to do work
define: energy intake
Energy intake: energy obtained from the food we eat
What are the 3 energy yielding nutrients? What also yields energy but is not a nutrient?
- carbohydrate, lipids, proteins
- alcohol
Where is energy found in a molecule?
found in the bonds that hold molecules together
During cellular respiration ____ are broken to retrieve the energy
bonds
define: energy expenditure
Energy expenditure: energy used to fuel basal metabolism, physical activity, processing food
define: basal metabolic rate; how much burned energy does it account for?
Basal metabolic rate (BMR): amount of energy the body needs to perform life sustaining functions over a period of time
- 60-75%
What are factors associated with a higher BMR (5)? What is the main controllable one?
- Genetic factors
- Male sex
- Younger age
- Taller height
- Higher lean body mass (main controllable factor)
Define: diet-induced thermogenesis; how much burned energy does it account for?
Diet-induced thermogenesis: thermic effect of food
- 10% of energy expenditure (max 15%)
Fill in the blank: Diets high in ____ promote a higher thermic effect. Diets high in _____ promote a lower thermic effect
- Now explain why
- protein
- fats
- because more energy is required to process proteins and less is required for fats
Define: physical activity; how much burned energy does it account for?
Physical activity: body’s voluntary movement that leads to the expenditure of calories (~15-30%)
How is energy stored in the body
- Some stored as carbohydrates in the form of glycogen
- Most stored as fat within the vacuoles of adipocytes: fat cells
- In the vacuole, energy is stored in the form of triglycerides, fatty acids, and fat soluble vitamins
Fill in the blank: Adipocytes can ____ when they reach maximum size
- divide
How is energy retrieved in the body. Where is most energy retrieved from?
- glucose and amino acids are metabolized to form ATP
- glycogen is converted into glucose
- body proteins are converted into amino acids
- most energy is retrieved from adipocytes; fatty acids and triglycerides are released into the blood
Why is maintaining lean mass important when in an energy deficit?
Body proteins are also used for energy when we are in an energy deficit; maintain lean body mass to make sure you don’t lose muscle
Describe some reasons we can gain weight
- increase lean mass by increasing muscle and bone mass through resistance exercise
- consistent energy surplus leads to fat mass increase
- body water content leads to fluctuations
- increase glycogen storage (max 1-2kg of weight)
Fill ion the blank: More cells an individual has, the greater room for _________
water volume in the extracellular space
When we lose weight, where does it go?
Weight is lost through the air we breathe out (water and carbon dioxide)
If 10kg of body fat is metabolized, how much becomes water and how much becomes carbon dioxide?
1.6kg as water and 8.4kg as carbon dioxide
What are some problems with obesity
- Psychiatric and psychological problems; depression and low self-esteem
- Asthma and breathing problems at night (sleep apnea)
- Gallstones
- Type 2 diabetes
Gynecological problems including an abnormal menstrual cycle and infertility - Cardiovascular disease including high blood lipids, atherosclerosis, hypertension, and stroke
- Breast, colon, prostate, and uterus cancer
- Arthritis
define: adipocytes
Adipocytes: fat cells; secrete adipokines. stores energy in vacuoles in the form of triglycerides, fatty acids, and fat soluble vitamins
define: adipokines
Adipokines: messengers that communicate with other body tissues
Fill in the blank:
- Below a certain level of fat mass, adipokine secretion has ______________ effect
- Above a certain level of fat mass (obesity), adipokines are more likely to promote ____________ and ________
- a health promoting maintaining
- low-grade inflammation and disease
define: leptin
Leptin: AKA fullness hormone; adipokine that acts on the brain’s hypothalamus to promote satiety (fullness)