Energy Balance and Obesity Flashcards
what are the major sources of stored energy
Triacylglycerol and glycogen
minor contribution from protein
What is the most concentrated form of stored energy in animals?
Triacylglycerol: fatty acids must be released to be used to generate ATP
Energy content of TG, protein, carbs
37 kJ/g for TG compared to 17 kJ/g
for protein and 16 kJ/g for carbohydrate
Why are TG such an efficient energy source
Fatty acids of TG are highly reduced
TG are stored in an anhydrous form
What does an excess of TG result in
obesity
which province has the highest obesity rate in Canada
Sask 48%
BMI index
Weight/Height^2
(kg,m)
18-24: normal
25-29: overweight
>30: obese
BMI underestimates obesity
What is obesity
A condition where a person has accumulated so much body fat that it has a negative effect on their health
How odes fructose contribute to obesity
Used as a food sweetener
Fructose is lipogenic
There is no feedback for fructose
fructose converts to TG in an unregulated manner
Fructose bypasses phosphofructokinase which is the regulatory step in glycolysis. Fructose also tends to create more fatty acids because it is lipogenic. It activates ACC and FAS
What is Ghrelin? Response in response to weight loss
Hunger hormone produced by gastrointestinal tract
relesaed when your stomach is empty
in response to weight loss , body tries to get back to orginal weight and stimulates ghrelin
What does you body do in response to caloric deprivation
Reduction in energy expenditure
Increased hunger
Function of insulin
Stimulates uptake of glucose from circulation into tissues, inhibits breakdown of fat, stimulates production of fat
how is excess glucose stored as fat
Glucose–>Acetyl CoA–> Citrate–> Acetyl CoA –> Fatty acid–> TG
Converts excess glucose to fatty acids through the TCA cycle to be stored as TG
why is rate of obesity increasing
Increase in energy consumption without an increase in energy expenditure
how does your body react when you use caloric deprivation to promote weight loss
Reduction in energy expenditure and incresaed hunger
