Ancel Keys: Experiments in Starvation and Refeeding Flashcards
what was the aim of the minnesota experiment
to characterise the physical and mental effects of starvation on healthy men by observing them under normal, starvation and re-feeding conditions
fat content _____ in the first stage and then ______
falls, and then plateaus
in the experiment, what was noted regarding organs
decraesed in size
changes in fat mass are highly _____ from fasting to re-feeding
variable
how do you calculate the P-ratio
1/1 + a (deltaFat/deltaFat Free mass)
(Urinary N loss (g) x 6.25 x 18.6) / BMR
P-Ratio is _____ during fasting in the same individual but _____ between subjects
constant during fasting
varies between subjects
BMR decreases during fasting and then _____
plateaus
Nitrogen urinary loss ______ during fasting
decreases
Body Weight ______ during fasting
decreases
P-ratios during starvation and re-feeding are strongly ______ with each other and fat mass
strongly
individual P-ratios are _____ during starvation and re-feeding
conserved
Pre-starvation % fat mass is the most important predictor if inter-individual variability in _ -_______
P-ratio
higher % body fat = ____ P-ratio
lower
higher % initial body fat correlates with greater ability to mobilise energy from ___ during starvation
fat
during re-feeding there is a greater tendency to
re-deposit fat
during starvation, what happens to protein and lean mass
conserved
any lean mass which has been lost will take longer to _____
replenish
increase in fat mass, but not fat-free mass, is inversely proportional to BMR during _______
re-feeding
change in thermogenesis, is greatest at the start of the ______ phase but declines as fat mass increases
re-feeding
high individual variability in fuel use between fat and protein means that weight loss and gain patters are ______________________
difficult to predict
High initial fat % conserves
protein mass
In recovery from starvation, fat is _____ but lean mass and protein is ______
replaced and lean mass and protein is not
changes in body fat mass almost exclusively explains _____ and _____ of BMR from starvation to re-feeding
decline and recovery
The decline in BMR is a physiological strategy to ____ fat mass during starvation
conserve
Physiological control of energy partitioning between fat and protein usage, as well as metabolic rate, are complimentary and homeostatic during ______ and _______
starvation and re-feeding
Do our bodies have a fat/lean compartmental memory
% initial body fat seems closely linked to P-ratio and pattern of lean/fat tissue mobilisation.
Do our bodies have a fat stores memory
Suppression of thermogenesis during re-feeding in inversely proportional to fat store recovery
Does yo-yo dieting caused fat gain
Re-feeding promotes a fat store overshoot which re-sets the fat/lean compartmental memory
mTORC control what
cell growth
what process are promoted by AMPK
catabolic processes
fatt acid oxidation
glucose uptake
glycolysis
autophage
mitochondrial biogenesis
what processes are inhibited by AMPK
anabolic processes are inhibited
fatty acid synthesis
glycogen synthesis
gluconeogenesis
cholesterol synthesis
what do PPARs do
increase function of organs
what does leptin do
activate immune cells
decreases glucose-stimulated insulin secretion
increase heart rate
regulates appetite, control of metabolism and energy homeostasis
regulating the menstrual cycle
regulates bone mass
what are the uncoupling proteins are there
UCP1/2/3/4
what does Melanocortin receptor 4 do
food intake, glucose metabolism, food anticipatory behaviour
