Psychology of Food/Eating LOs Flashcards
What factors contribute to feeling hungry or full?
Metabolic/ Homeostatic Hunger: driven by physiological necessity
Hedonic Hunger: eating for sake of pleasure; powerful desire for food in absence of any need for it
Peripheral factors: food in GI tract
Central factors: hypothalamus
Psychological Factors: perceived time of day
What sensory factors are involved in eating
Gustation, Olfaction, Flavor, Taste/smell interactions, temperature, colour, texture, sounds, chemesthesis
Gustation
is a sensory factor involved in eating. ‘True taste’ differentiates from terms like ‘flavour’.
Basic taste qualities: sweet, sour, salty, bitter and umami.
Taste acuity (ability to detect and identify a tastant), taste sensitivity (rating of intensity of tastant)
Qualities (metallic, alkaline, koumi) not universally accepted. Hedonic attributes can express nontaste value (eg. Scrooge is a bitter man)
Olfaction
odour names often derived from object that produced it (eg. minty, smoky), common substances however are mixtures of odourants (eg. evergreen, curry, coffee). Categorization by comparison.
Two olfactory routes (orthonasal and retronasal). Some odours are disliked orthonasally but liked retronasally (strong cheese, fish, eggs). More difficult to use retronasal route to identify food
Flavour
primarily comprised of taste and smell but also touch/texture (mouthfeel), temperature, sight, sound and sometimes pain/irritation.
No verb exists in English to express perception of flavour.
Closely linked to systems for learning, memory, emotion and language which all contribute to food preference and cravings.
taste/smell interactions
taste can affect the perceived intensity of aromas and vice-versa
Temperature
as food is heated there is an increase in volatile compounds released, possible increasing intensity of odours.
Wide variation in detection of tastes as temperature increases
Colour
more difficult to identify inappropriately coloured foods including jelly, sherbert, wine gums and fruit-flavoured beverages.
Increasing intensity of colour increases perception of taste/flavour intensity
Texture
higher viscosity decreases taste and flavour intensity.
Interacts with sound: crispness and crunchiness
Sound
noise decreases flavour perception making food taste blander (eg. airplane food)
Chemesthesis
sensations of irritation or burn that arise when chemical compounds in food activate receptor mechanisms for pain, touch or thermal perception (eg. capsaicin from chili pepper),
high concentrations of some tastants or odourants cause irritation.
Although taste and odour components produce adaptation, irritants cause sensitization (increasing pain and irritation in the short term).
Preference for spicy food may be due to desensitization over the long run and/or association with other flavors
What are some hedonic responses to flavour
Hedonic Reponse: affective response to foods or their components, liking of a food increases chewing and swallowing rates (you eat faster), knowing good was prepared just for you makes it taste better
Pleasure principle: eating has been called one of life’s greatest pleasures. Endogenous opioids/endorphins implicated in food cravings. Preferences for sweet taste are under opioid control: opioid antagonists increase, whereas antagonists decrease preferences for sweet taste in humans. Alcohol cravings may be mediated through endogenous opioid peptides
Taste: innate preference (sweet, salty) or rejection (sour, bitter). Plant derived lakaloids and glycosides and other environmental toxins tend to have a bitter taste; identifying (and rejecting) bitter compounds may confer an evolutionary advantage. Exposure may or may not modify liking. Hunger or need increases liking of sweet or salty, respectively. Sensory-specific satiety: satiety decreased hedonic reactions. Age raises preferred concentrations (sweet, salty). Presence of sugar, fat or calories enhances liking.
Odour (otho/retronasal): difficult to do research on innate preferences. Pleasure obtained from smells reflects experience via conditioning. Exposure modifies liking. Age raises preferred concentrations.
Trigeminal stimulation (eg. of free nerve endings by spices or ethanol): inherently unpleasant, exposure enhances liking (hedonic reversal) which may be due to the antimicrobial properties of chilis or the presence of vitamins A and C
Individual differences: may be innate or learned. Variation within a population can be due to cultural variation, demographics or psychographics.
Hedonic optimum: best concentration of a substance in a particular food or beverage. Differs among foods/cultures but generally has an inverted U shape with increasing concentration. Must be expected (in appropriate context)
What genetic factors affect taste, flavour and food preferences
Genetics: some tastes inherently preferred, some inherently disliked.
Sweet: preference for sweet is stronger than for any other taste. Sweet foods tend to contain sugar, which is high in calories and thus energy. Newborn babies suck sugary nipples more.
Salty: strong preference exists for salty tastes. Salt is required for regulating the body’s fluid balance. Newborns do not appear capable of detecting salty tastes
Bitter: bitter taste not preferred. Supertasters (people who are more sensitive to bitter compound in foods including coffee, grapefruits and beer), correlated with increased number and density of certain papillae on the tongue containing taste buds
What are some environmental factors that affect taste, flavour and food preferences
Familiarity (mere exposure effect): with repeated exposure new foods will be accepted, only when food is ingested did this occur. Due to learned safety (when ingestion is not associated with negative consequences, increased acceptance results).
Conditioned taste aversion: tastes previously associated with negative postingestive consequences (nausea or vomiting) are avoided. Adaptive response to potentially dangerous toxins.
Types of food aversions: distasteful, dangerous, inappropriate, disgusting
Medicine effect: foods associated with recovery from illness may become preferred.
Flavour-Flavour Learning: pairing novel taste/flavour with a preferred one increases preference for it, people given unfamiliar herbal teas some sweetened, other unsweetened -> preference for sweetened teas increased
Flavour-nutrient learning: taste associated with higher calories are preferred.
Dessert Effect: eating dessert at the end of a meal increases preference for sweet taste of dessert, rewarding a child for eating spinach with a dessert will not increase preference for spinach but for the dessert
Social factors: reformatory study (Escalona, 1945): mothers in prison had their children living in the prison nursery, many babies showed dislike for tomato or orange juice, each juice offered with equal frequency, equal numbers of babies preferred each juice. Preference reversed every few weeks. Reversal occurred when person feeding a baby was reassigned. Babies’ preference/dislikes matched those of their current caregiver
culture/cuisine: depends on available foods, techniques, flavourings and cultural constraints
Consumptions norms and consumption monitoring
Consumption Norms: aspects of the environment influence the quantity of food that is acceptable to consume. Eg. packing size or eating behavior of your dinner companion
Consumption Monitoring: monitoring food consumption helps reduce discrepancies between perceived and actual consumption amounts. Eg. paying attention to the amount eaten vs eating until all the food is gone. Food choice may be emphasized to the neglect of food quantity (eating whole package of low-fat cookies)
