Exercise and hunger

Question 1

what is appetite?

Answer 1

Desire to eat

External and psych factors

What do I want to eat?

• Smell
• Sight
• Temperature
• Humidity
• Learned
• Situation

Question 2

what is hunger?

Answer 2

Internal drive to eat

Central

• Hypothalamus
• Vagus nerve

Peripheral

• Blood glucose
• Hormones

When can I eat?

Question 3

CCK effect on food

Answer 3

decrease

Question 4

PP effect on food

Answer 4

decrease

Question 5

PPY effect on food

Answer 5

decrease

Question 6

GLP-1 effect on food

Answer 6

decrease

Question 7

excess glucocortoids effect on food

Answer 7

increase

Question 8

leptin effect on food

Answer 8

decrease

Question 9

ghrelin effect on food

Answer 9

increase

Question 10

adiponectin effect on food

Answer 10

no role

Question 11

insulin effect on food

Answer 11

undecided

Question 12

neuropeptide y effect on food

Answer 12

stimulate intake

Question 13

what happens when the stomach is empty?

Answer 13

increased ghrelin = increased appetite

CCK, GLP-1, PYY decrease

Question 14

what happens when the stomach is full?

Answer 14

decreased ghrelin = decreased appetite

CCK, GLP-1, PYY all increase

Question 15

ghrelin

Answer 15

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

Question 16

leptin

Answer 16

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

Question 17

CCK

Answer 17

released from SI

Neuropeptide

15 min

reduces urge to eat

causes gall bladder to release bile

Question 18

PP

Answer 18

secreted from SI - suppresses hunger for long time

Acts on hypothalamus

Pancreas

Increase post food intake

Question 19

PYY

Answer 19

influenced by energy + composition

1 h post feeding

IV
- Lowered EI (lean/obese)

Question 20

GLP-1

Answer 20

Small intestine and colon - local to GI tract

amount released proportional to EI

Promote wt loss (peripheral/central admin)

Question 21

OXM

Answer 21

Co released with GLP-1

Proportional to EI


Question 22

adiponectin

Answer 22

energy homeostasis

related to appetite - decrease with obesity and increase with weight loss

Question 23

insulin

Answer 23

suppress hunger

stimulates leptin release

Increase amount of triglycerides in adipocytes -
some influence on hypothalamus

Question 24

glucocortoids - deficiency

Answer 24

anorexia

- adrenal gland failure

Question 25

gut hormones

Answer 25

ghrelin leptin CCK PP PYY GLP-1 OXM adiponectin insulin glucocortoids

Question 26

perception of hunger and ex

Answer 26

Lower Appetite at 0.5, 1 and 1.5 h with exercise

Question 27

acetylated ghrelin (active form)

Answer 27

No differences Ex vs CON but a difference in sex (lower in females)

Question 28

GLP-1 (decrease food intake)

Answer 28

Higher GLP-1 early and late following exercise Greater in obese Some effect of not working with hormones

Question 29

what is the hormonal response to ex - lean and obese?

Answer 29

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

Question 30

is energy intake greater in the cold?

Answer 30

yes overweight Walking (45 minutes) 8°C vs 20°C Appetite hormones Total energy intake More carbs eaten specifically

Question 31

appetite hormones and temp

Answer 31

Acylated ghrelin higher post ex in CON No effect on total ghrelin - Inverse correlation with BW No effect on PYY

Question 32

conclusion of ex in the cold

Answer 32

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

Question 33

does hypoxia suppress appetite in HIE and MIE?

Answer 33

yes Condensed intensities together Higher in normoxic during ex Higher appetite in normoxic overall

Question 34

was acetylated ghrelin influenced by oxygen?

Answer 34

yes Hypoxia has lower acylated ghrelin ( lower drive to eat) Higher in normoxic

Question 35

conclusions: appetite and oxygen levels

Answer 35

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

Question 36

what are some other factors to be aware of?

Answer 36

Age Sex Body composition Physical activity levels Environmental factors duration of exercise Palatability of available food. Individual differences

Question 37

CCK given to rodents

Answer 37

if given to rodents - decrease - gastric emptying - feeding (central) - meal size (peripheral) - Duration (peripheral)

Question 38

glucocortoids excess

Answer 38

hyperphagia
 - Excessive consumption of food - Can also occur if lesional injury to part of hypothalamus