Exercise and hunger Flashcards
what is appetite?
Desire to eat
External and psych factors
What do I want to eat?
- Smell
- Sight
- Temperature
- Humidity
- Learned
- Situation
what is hunger?
Internal drive to eat
Central
- Hypothalamus
- Vagus nerve
Peripheral
- Blood glucose
- Hormones
When can I eat?
CCK effect on food
decrease
PP effect on food
decrease
PPY effect on food
decrease
GLP-1 effect on food
decrease
excess glucocortoids effect on food
increase
leptin effect on food
decrease
ghrelin effect on food
increase
adiponectin effect on food
no role
insulin effect on food
undecided
neuropeptide y effect on food
stimulate intake
what happens when the stomach is empty?
increased ghrelin = increased appetite
CCK, GLP-1, PYY decrease
what happens when the stomach is full?
decreased ghrelin = decreased appetite
CCK, GLP-1, PYY all increase
ghrelin
discovered in 1999
released by stomach and duodenum
Orexigenic
Meal initiator
Appetite stimulator (lean and obese)
Lower in obese
Increase following diets
Active / inactive form
Disappears within 20mins/half an hour
Eat quickly - full before stomach tells you, you are - over eat
leptin
produced in white adipose tissue
Stimulates release of MSH - melanocyte stimulating hormone - suppress hunger
Controls level of stored body fat
Defective in obese - leptin resistance
Interacts in same area of hypothalamus
Reduces hunger
Correlates with fat stores
Drop completely in starvation
Interactions with neuropeptide Y - suppress release
Less leptin released as lose weight - appetite not suppressed as much
CCK
released from SI
Neuropeptide
15 min
reduces urge to eat
causes gall bladder to release bile
PP
secreted from SI - suppresses hunger for long time
Acts on hypothalamus
Pancreas
Increase post food intake
PYY
influenced by energy + composition
1 h post feeding
IV
- Lowered EI (lean/obese)
GLP-1
Small intestine and colon - local to GI tract
amount released proportional to EI
Promote wt loss (peripheral/central admin)
OXM
Co released with GLP-1
Proportional to EI
adiponectin
energy homeostasis
related to appetite - decrease with obesity and increase with weight loss
insulin
suppress hunger
stimulates leptin release
Increase amount of triglycerides in adipocytes -
some influence on hypothalamus
glucocortoids - deficiency
anorexia
- adrenal gland failure
gut hormones
ghrelin
leptin
CCK
PP
PYY
GLP-1
OXM
adiponectin
insulin
glucocortoids
perception of hunger and ex
Lower Appetite at 0.5, 1 and 1.5 h with exercise
acetylated ghrelin (active form)
No differences Ex vs CON but a difference in sex (lower in females)
GLP-1 (decrease food intake)
Higher GLP-1 early and late following exercise
Greater in obese
Some effect of not working with hormones
what is the hormonal response to ex - lean and obese?
GLP-1 increase greater in OW/OB
Suppressed of circulating deacylated ghrelin greater in OW/OB
PYY increase was greater in lean
No effect on food intake
- Hormones not all that is important
Ad lib buffet
- Eat until they full if know?
- If knew what was going on might not have ate as much as they wanted
is energy intake greater in the cold?
yes
overweight
Walking (45 minutes)
8°C vs 20°C
Appetite hormones
Total energy intake
More carbs eaten specifically
appetite hormones and temp
Acylated ghrelin higher post ex in CON
No effect on total ghrelin
- Inverse correlation with BW
No effect on PYY
conclusion of ex in the cold
Increase post ex EI in men and women
Acylated ghrelin - drive to eat??
OW = inc EE by walking.
- Winter (Cold) – incr EI?
Swimming non–weight-bearing for weight loss
does hypoxia suppress appetite in HIE and MIE?
yes
Condensed intensities together
Higher in normoxic during ex
Higher appetite in normoxic overall
was acetylated ghrelin influenced by oxygen?
yes
Hypoxia has lower acylated ghrelin ( lower drive to eat)
Higher in normoxic
conclusions: appetite and oxygen levels
Short exposure to normobaric hypoxia whilst performing exercise causes suppressions in appetite
Decreases circulating plasma acylated ghrelin concentrations.
Appetite responses to exercise do not appear to be influenced by exercise modality
what are some other factors to be aware of?
Age
Sex
Body composition
Physical activity levels
Environmental factors duration of exercise
Palatability of available food.
Individual differences
CCK given to rodents
if given to rodents - decrease
- gastric emptying
- feeding (central)
- meal size (peripheral)
- Duration (peripheral)
glucocortoids excess
hyperphagia
- Excessive consumption of food
- Can also occur if lesional injury to part of hypothalamus
