Obesity - Feedback Models Flashcards
What would happen if there is an increase in the inflow rate?
Basal Metabolic Rate (BMR) =
part of the calories out
- proportional to body mass
How does the BMR change when the number of calories increases?
What is the LDR when incorporating PAL and BMR?
EXAMPLE 1:
initial energy = 0 kcal
BMR = 20 kcal/kg/day
calories in = 2200 kcal/day
calories out = 2000 kcal/day + (BMR * PAL * EBM)
conversion factor = 0.13 g/kcal
PAL =2
What does the LRD look like?
How do you work out EBM?
Graph for change in body mass?
What is the difference between the basic model and the feedback model?
How is equilibrium reached in the calorie model?
Obesity and dieting
main objective: maintain/change weight
there is a GOAL
main mechanism:
- ______ calories in (reduce food intake)
- _____ calories out (increase food intake)
restrict
increase
What is linear proportional control? (3)
- basic form of feedback control
- eg. thermostat/cruise control/thermoregulation
- requirements: target value/ set point
What are the assumptions about the calorie model? (3)
- calories out = constant
change in body mass = due to calories in only - Target Change in Mass = given/known
= change in body mass = initially 0 kg
What is the simplified diet model?
EXAMPLE 2:
we want to lose 5 kg
initial energy = 0 kcal
calories out = 2000 kcal/day
control constant = 80 kcal/kg/day
calories in = 2000 kcal/day + (control constant * diff)
conversion factor = 0.13 g/kcal
Model settings
initial time: 0 weeks
final time: 3 years = 156 weeks
time step: 1 day = 1/7 weeks
units of time: weeks
What does the LRD look like?
What does the calories in vs calories out graph look like in example 2?
What does the graph for change in body mass look like in example 2?
What does the LRD look like for the Less Simplified Diet Model?
EXAMPLE 3
we want to lose 5 kg
initial energy = 0 kcal
control constant = 80 kcal/kg/day
BMR = 20 kcal/kg/day
calories in = 2000 kcal/day + (control constant * diff)
calories out = 2000 kcal/day + (BMR * PAL * EBM)
conversion factor = 0.13 g/kcal
PAL = 2
Model settings
initial time: 0 weeks
final time: 3 years = 156 weeks
time step: 1 day = 1/7 weeks
units of time: weeks
What does the LRD look like?
What does the calories in vs calories out graph look like in example 3?
What does the graph for the change in body mass look like in example 3?
