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Flashcards in eating regulation Deck (20)
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1

What regulates eating?

energy deficit
nutrient deficits
pleasure seeking

2

How is energy homeostasis achieved?

Energy balance = Intake – Expenditure

Caloric intake = metabolic rate, thermogenesis, activity

3

what are the parameters of regulation?

Quantity (E Intake): meal-size and frequency

Quality = Composition of Meal: food selection
recruits motivational, reward, learning, memory and cognitive systems

Energy Output: physical activity and activity of sympathetic NS
recruits systems controlling thermogenesis, basal metabolism and movement

Energy Storage: body weight and composition
recruits endocrine/hormonal and neural systems

eating can also be voluntary

4

What is short term control?

regulates meal size and frequency

dynamic parameters (minutes, hrs)
positive and negative feedback from the ingested meal/ GI tract = “hunger and satiety signals

5

What is long term control?

defends BW / adiposity
proportional to total body fat
“adiposity signals”: insulin, leptin

6

What are the three phases of short term regulation of feeding behavior?

Cephalic
Gastric
Substrate

7

What is the cephalic phase of short term regulation of feeding and what hormones are released?

Cephalic - hunger

Ghrelin released when stomach is empty
Activates NPY- and AgRP-containing neurons in arcuate nucleus

8

What is the Gastric phase of short term regulation of feeding and what hormones are released?

Gastric - feeling full

Gastric distension signals brain via vagus

Works synergistically with CCK released in intestines in response to certain nutrients

Insulin also released by β cells of the pancreas - important in anabolism

9

What is substrate phase?

the time after a meal is eaten until the hunger feeling

10

When is the blood insulin levels the highest?

during substrate phase

11

What is prandial and post absorptive state?

Prandial state - Anabolism: Energy storage as glycogen and triglycerides

Postabsorptive state - Catabolism: Breaking down complex macromolecules

12

What are the direct factors that control eating?

Orosensory effects (4Ts: taste, texture, temp, + to smell)

Food in the GI tract (mechano-, chemo-, osmo-rec.)

= stimuli that directly engage receptors in the mucosa of the alimentary tracts

13

What are indirect factors that influence eating?

Metabolic factors and body temperature
Postingestive effects of digested nutrients
GI hormones
Rhythms (circadian, hormonal, annual cycles)
Learned effects (preferences, and aversions)
Cognitive factors (dietary awareness, beliefs)
Cultural, ethnical, social, economical factors

= effects that are not derived from a direct receptor interaction with a meal

14

What are general features of hormones that affect food intake?

Released from the GI tract in response to intraluminal nutrients

Regulate appetite acting directly on CNS receptors, or indirectly via nX.

Some are synthesized and released also in the brain

Potential therapeutic targets

15

What are the anorexigenic GI hormones?

CCK
PYY
PP,
amylin glucagon
incretin hormones: GLP-1

16

What affects does anorexigenic hormones have on food intake?

increase satiety
decrease appetite
decrease food intake

17

What are the orexigenic go hormones?

Ghrelin

increase hunger
increase appetite
increase food intake

18

Where is direct control of meal size found?

in the hind brain
central pattern generators are located in the behind brain

direct regulation of ingestion and rejection are present in the hindbrain

indirect regulation is absent

19

What is the function of leptin?

Regulates body mass
Decreases appetite
Increases energy expenditure

20

What will leptin depletion lead to?

Incites adaptive responses
to fight starvation