Midterm Flashcards
1 Kcal = ? KJ
4.184 KJ
What is an Atwater Factor?
Atwater factors calculate the amount of energy in food available to humans.
Atwater factor for CHO?
4 kcals
Atwater factor for FAT?
9 kcals
Atwater factor for PRO?
4 kcals
Atwater factor for Ethanol?
7 kcals
Why do CHOs differ in their digestibility?
Fibres are either undigestible (insoluble) or only partially digestible (soluble).
How is energy lost from PRO?
When nitrogen is excreted in urea, some combustible H is lost as well.
What is the hierarchy of oxidation?
The order in which macronutrients are consumed:
- Ethanol
- Carbohydrates and Proteins
- Fats
What is autoregulation?
The ability to change macronutrient expenditure in response to different intakes to keep stores stable.
What are the three components of energy expenditure?
RMR, TEF, EEA
What micronutrient drives fuel selection?
CHO
How does energy expenditure change over a lifespan?
From childhood to early adulthood, energy expenditure increases. After this point, energy expenditure generally decreases with age. It is important to note that individuals of the same age may have very different energy expenditures.
Obligatory thermogenisis
Then energy required for (and heat generated by) digesting, absorbing, and metabolizing nutrients
Facultative thermogenesis
Specialized pathways for creating heat to maintain body temperature.
Brown fat metabolism and shivering are forms of…
Facultative thermogenesis
When weight is lost and then regained, what happens to RMR?
RMR drops significantly with weight loss, and when weight is regained it remains depressed from starting levels.
What percentage of DIT is obligatory?
50-75%
Explain the issues with set-point theory
Set-point theory fails to explain why the population is seeing its set-points rise. It also fails to account for why after periods of severe fasting and subsequent refeeding we do not see a return to pre-fast RMR.
Explain the issue with settling point theory.
Settling point theory does not take into account the biological regulation of weight.
Define hunger
Sensations that promote food consumption
Define satiation
Sensations of fullness that occur during a meal and control cessation of eating.
Define satiety
sensations that determine intermeal periods of fasting.
Define orexigenic
Having a stimulating effect on appetite.
Anorexigenic
Causing loss of appetite
Where is leptin secreted?
From adipose tissue
The effect of leptin is…
Decreased food intake and weight loss
How does leptin interact with obesity?
Obese individuals have generally developed a resistance to leptin.