Term
| What is the cellular source of energy? |
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Definition
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Term
| What consequences come from positive energy balance? |
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Definition
- weight gain/obesity
- infertility
- cardiovascular disease
- insulin resistance |
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Term
| What consequences come from negative energy balance? |
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Definition
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Term
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Definition
| measurement of heat production |
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Term
| What are the potential errors of using a bomb calorimeter to mimic digestion? |
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Definition
- over-estimation
- we don't digest food like a bomb calorimeter
- doesn't take into account energy used for digestion and absorption |
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Term
| Why does fat provide more kcal/gram than CHO and protein? |
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Definition
| lipids have a higher ratio of hydrogen to oxygen (less oxidized) |
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Term
| What are the factors that affect heat of combustion of fatty acids? |
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Definition
1. chain length - longer the chain, more energy required
2. degree of unsaturation - more double bonds, less energy required |
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Term
| What is the heat increment of feeding (HIF)? |
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Definition
- thermic effect of food
- energy expended in digestion, absorption, distribution and storage of dietary nutrients |
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Term
| What are the four stages of partitioning energy from food? |
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Definition
1. gross energy -> fecal energy
2. digestible energy -> gases, urinary energy
3. metabolize energy -> heat increment
4. net energy -> basal metabolic rate |
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Term
| What are the three major components to energy expenditure? |
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Definition
1. basal metabolic rate (BMR)
2. thermic effect of food (HIF)
3. physical activity energy expenditure (PAEE) |
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Term
| What is the equation for calculating the basal metabolic rate? |
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Definition
BMR = A x [M^0.75] kcal/day
where A = 70 for humans
M = body weight |
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Term
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Definition
1. genetics - inheritance of fast or slow BMR
2. age - young > old
3. gender - men > women
4. exercise - changes body tissue proportions
5. temperatures - maintaining thermoregulation |
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Term
| What is indirect calorimetry? |
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Definition
| energy-releasing reaction in the body that depend on the utilization of oxygen |
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Term
| For indirect calorimetry, how is heat production estimated? |
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Definition
measuring:
- oxygen consumption
- carbon dioxide production
- urinary nitrogen loss |
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Term
| What is the respiratory quotient (RQ)? |
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Definition
- provides information about energy expenditure and biological substrate being oxidized
- ratio of metabolic gas exchange |
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Term
| What is the equation for calculating respiratory quotient? |
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Definition
| RQ = CO2 produced/O2 consumed |
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Term
| What assumptions are made when using RQ to determine energy expenditure? |
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Definition
- only CHO, fat and protein are metabolized
- there is no synthesis happening at same time as breakdown
- amount of CO2 exhaled = amount of O2 produced by tissues |
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