Term
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Definition
| hunger (MS) stomach growling, habits, lack of nutrients, blood glucose levels |
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Term
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Definition
| satiety hormones, high blood sugar |
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| • Determining foods we choose: |
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Definition
| nutrients, what tastes good, region/cultural |
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Term
| Control System theory of Hunger |
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Definition
two subsystems:
Short term
Long term hunger |
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Term
| o Short term hunger (STH) |
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Definition
• Trying to maintain balance between energy consumed and energy burned. Day to day.
• EX: I exercised I need more calories
• Controls meal frequency and size. |
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Term
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Definition
• Regulating long term energy stores.
• EX: grizzly bears that hibernate have a strong LTH system- built to regulate how much energy storage they have.
• Adipose tissue and weight management- our brains can detect how much fat we have. |
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Term
| • Activation of STH input- |
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Definition
2 inputs: glucose +FA
o Input- decrease in available glucose
• Primary input for STH
• Glucoreceptors in the liver and portal vein communicate info about glucose availability to the brain.
• Exp: induce by injecting 2-DG a glucose molecule that is radioactive and will bind to receptor and turn it off. Receptos wont know if theres other glucose molecules/any energy at all. This makes you hungry.
- decrease in available fatty acids (lipids)
• Exp: induce by injecting MA
• Effect at abdominal organs- cant sense FA |
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Term
| Since FA and Glucose are both sufficient inputs for hunger |
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Definition
| • This suggests two set points for hunger.= extra hungry. Homeostatic point wanting this much glucose and this much fat= they are different but they are additive processes. |
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Term
| Having both inputs FA and glucose is similar to thirst- |
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Definition
| IC and EC dehydration are additive/2 points |
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Term
| o Deactivation of STH factors include |
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Definition
mouth
stomach
CCK
blood and liver |
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Term
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Definition
Sham feeding increases food intake but eating eventually stops. Let food get in to the stomach but then immediately remove it.
• Repeated exposure to same item results in:
o Alliesthesia
o Habituation (sensory specific satiety) |
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Term
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Definition
Preloading decreases food intake (stretch receptors)
Nutrient receptors –cravings
• Rats need protein
• Salt in humans |
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Definition
Released when food enters the duodenum- satiety signal
• Higher doses animals stopped eating and also had destressed and adversive= when you eat too much. System is very sensitive.
• Injection terminate food intake
• Specific mechanism debated
• Might slow the emptying of the stomach
• Brain inhibition |
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Term
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Definition
Glucose injected into portal vien specifically terminates feeding in animals
• Glucoreceptors
Indirect evidence of lipid monitoring as well.
• Ex: intravenous feeding in humans
o Carbs and protein-> report subjective huger (less satisfied)
o Add fat (lipids) -> hunger decreases |
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Term
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Definition
o Appears to be relatively stable over lifetime
• Biased toward gaining (1-2lbs/year)
Helpful bc biased toward losing you would soon be nothing. |
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Definition
o Difficult to select and maintain weight for long periods of time.
• Most people that go on diets people actually gain weight.
o Trick body into thinking its starving: body conserves energy |
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Term
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Definition
| LTH is regulating a set point for adipose tissue |
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Term
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Definition
o Homeostatic mechanism
o Interact with STH system
• LTH wants x number calories in reserve; if below it will tell STH to eat
o More complicated than caloric input and energy output
• Early life factors
Starvation periods early in life might effect you later
• Practice
The more times you try to diet the harder it gets to lose weight. Body gets better at predicting you and will slow metabolism |
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Term
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Definition
| focus on adipose tissue (influenced by genetic factors, brain factors, biochemical factors |
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Term
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Definition
| The four Fs- feeding, fighting, fufilling monogonous relationships, drinking |
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Term
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Definition
| (satiety)- if you didnt have this you would always be hungry. |
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Term
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Definition
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Term
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Definition
| Basal metabolic rate can be measured by heat production. People that are always warm have a high metabolic rate. |
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Term
• Factors related to Adipose Tissue
-correlation
-adopted child/twins
what genes do: |
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Definition
o Gentic Component
• Positive correlation between biological relation and adult weight
Adopted children more similar to biological than adopted
Identical twins (even when raised apart) more similar in weight than fraternal twins.
• What might genes do?
Set basal metabolism
Determine sensitivity to satiety signals (ex: leptin gene) getting full easily vs awhile? Number of leptin receptors |
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Term
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Definition
o Hormonal and hypothalamic regulation of body fat and feeding.
• Hypothalamus: ancient lowest portion of brain |
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Term
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Definition
stimulation elicits eating
• Lesion-> voluntary starvation |
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Term
| o Ventromedial hypothalamus |
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Definition
• Stim terminates eating
• Lesion -> chronic overeating |
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Definition
(feeding cue)
• Synthesized when lack of available energy
• Injections elicits ravenous food seeking |
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Term
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Definition
• Receptors in VMH
Lesioning VMH destroys them, resulting in overeating
• Appears to interact with CCK
• May also modify NPY |
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Term
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Definition
• Problems with any of the players in the model could disrupt the regulation of adipose tissue.
• Remember: system is biases toward saving excess energy
o Ex: famine hypothesis |
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Term
| potential causes of obesity: |
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Definition
o Possible regulation problem
o Possible set point issue
o Possible dietary and conditionin issues
Possible combination of all these factors |
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Term
| o Possible regulation problem explanation for obesity |
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Definition
• Some problems in the systme prevents it from regulating the set point for adipose tissue (disrupts the systems ability to behave in a homeostatic manner)
hyperinsulinemia
insulin tolerance/resistance
hypothyroidism |
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Term
| o Possible set point issue |
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Definition
| • Regulation of homeostasis is working, but persons biological set point for adipose tissue is elevated for some rease |
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Term
| o Possible dietary and conditionin issues |
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Definition
More susceptible to external food cues that trigger eating and or hunger.
Get greater pleasure from high sugar and high fat foods (which encourages eating motivated by pleasure rather than merely addressing energy needs.
More susceptive to the effects of high food variety
• Greater variety -> less habituation -> overeating
• If one food item doesnt give you all the nutrients you will try something new and that will bring different nutrients.
• Greater variety= less habituation =over eating. |
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Term
| Non-Homeostatic Factors for Hunger and Eating |
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Definition
• Humans as omnivores- eat everything.
• Innate taste preferences
• Eating as a sensory experience
o Humans ability to acquire tastes
• Variety- we like to taste different things |
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Term
| • Innate taste preferences |
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Definition
o Prefer sweet things- quick energy carbs, less risk of toxins
o Fat- protein ->AA -> supports bigger brain
o Salt- crucial for thirst and water-body balance |
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Term
| • Eating as a sensory experience |
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Definition
o Taste as a “selection” mechanism
• Taste-evoked drinking and eating
Can also work for avoidance
• Hedonic value
Endorphins
Serotinin |
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Term
| o Humans ability to acquire tastes |
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Definition
• Gradual sampling to acquired appeal
“mere exposure effect” |
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Term
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Definition
o Bulimia: binge purge cycle elevates low serotonin
o Anorexia: starvation reduces elevated serotonin. |
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Term
| • Eating as a social experience |
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Definition
• Food becomes associated w/valued social commodities (reward, participating in cultural events, opportunity for social interaction).
• Note: not eating (even when hungry) may also be influenced by social forces. Interviews situation |
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Term
| • Eating as an emotional experience or in response to an emotional state stress |
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Definition
o Stress
• Increased cortisol release -> disrupts insulin function
Increased hunger
Increased fat storage
• Women may be more susceptible
Perhaps because restrained eaters and are worried about calories. |
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Term
| • Eating as an emotional experience or in response to an emotional state depression |
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Definition
o Depression
• Has Positive correlated w/obesity in some studies but not causal. Linked to cortisol response.(lack of pleasure).
Stronger positive correlation with weight loss.
Several anti-depressants linked to weight gain. |
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| • Eating as a control issue |
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Definition
o Unrealistic standards of attractiveness encourage disordered eating and thoughts about food. (negative association w/food hate the burger)
o Eating disorders as control disorders
• Sense of autonomy and self-control negative correlated with obesity.
o Feeling “loss of control” may encourage overeating. Stress response. |
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Term
| Mook’s “what the hell!” effect***read |
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Definition
| Suggests binging may lead to weight gain in some cases. Give ppl milkshakes and ppl will say i was trying to diet, but i blew it/broke the diet so im just going to keep eating= binging. |
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Term
| • Hunger triggered by conditioned cues |
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Definition
o Cue + food
Food-> insulin release (causes glucose to be absorbed)
o Cue (without food eventually) -> insulin release |
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