eating and appetite Flashcards
(20 cards)
What is Set Point Theory?
It suggests hunger results from an energy deficit. The body seeks to return to an optimal ‘set point’ to maintain homeostasis (Keesey & Powley, 1986).
What are three problems with Set Point Theory?
- Evolutionary implausibility due to inconsistent food availability. 2. Lack of empirical support (e.g., Lowe, 1993). 3. Ignores environmental, learned, and social factors.
What is Positive Incentive Theory?
The theory (Berridge, 2004) proposes that eating is driven by anticipated pleasure rather than energy needs. Cravings and cues initiate eating.
What factors influence eating according to Positive Incentive Theory?
Flavour, learning, time since last meal, stomach contents, and blood glucose levels.
What is a conditioned taste preference?
A learned association where a flavour is paired with a positive experience (e.g., Sclafani, 1990).
What is a conditioned taste aversion?
A learned avoidance of a flavour after it is paired with an unpleasant experience like nausea (e.g., LiCl with flavour).
How can social factors influence food preferences?
Animals can adopt food preferences by observing others (Galef, 1995).
What is the significance of Harris et al. (1933) study on vitamin B1?
Rats learned to choose a complete diet when B1 deficient, but only when choices were limited.
What triggers pre-meal hunger according to Woods (1991)?
Anticipation of food triggers insulin release, lowering glucose, causing hunger before energy deficits.
What did Weingarten (1983) demonstrate with conditioned hunger?
Rats learned to associate a cue (light/buzzer) with food and ate more when the cue was present.
What role does the VMH play in eating?
It’s a satiety center. Lesions cause hyperphagia and weight gain (Hetherington & Ranson, 1940).
What is VMH syndrome?
Includes dynamic (rapid weight gain) and static (stable overweight) phases. Rats become finicky.
What role does the LH play in eating?
It’s a feeding center. Lesions cause aphagia and adipsia (Anand & Brobeck, 1951).
What are the side effects of LH lesions?
Motor disturbances and lack of responsiveness, not just hunger issues.
What did Cannon & Washburn (1912) find about the stomach?
Stomach contractions correlate with hunger, but stomach is not necessary for hunger.
What did Koopmans (1981) show with transplanted stomachs?
Satiety signals can travel via blood, not nerves, as transplanted stomachs reduced eating.
What is the function of CCK?
A peptide that reduces eating in rats, possibly by inducing nausea (Gibbs et al., 1973).
What is leptin and its role in eating?
A hormone that reduces appetite and increases fat metabolism. Low levels cause overeating (Seeley & Woods, 2003).
Why is leptin not an effective obesity treatment in humans?
Most obese people have high leptin levels; injections often do not reduce eating.
What did Farooqi et al. (1999) show with leptin therapy?
Leptin successfully treated a child with no natural leptin, leading to significant weight loss.
