Volume, variety and SSS Flashcards
Hunger
absence of fullness that underlies readiness to eat (Rogers & Brunstrom 2016)
partly learnt response - when full, explain perceptions of hunger in relation to level of fullness since last meal, timing and/or size of previous meal and proximity of next
Expected satiety
inhibits intake before meal - perceptions before consumption, of ability of a food to stave off hunger
Expected satiation
within meal - perception, before consumption of ability of a food to deliver fullness
expected satiation/satiety can strongly influence pre-meal decisions about food/portions (Brunstrom et al 2008)
satiation
expectation can be learned, more familiar a food is, more filling it is expected to be
negatively correlated to energy density - higher energy density, less filling it’s perceived to be
routine decisions and automatic processing can lead to passive overconsumption
Portion size evidence
doubling portion served increased food intake by ~35% (Zlatevska, Dubelaar & Holden 2014)
people consuming larger portions report same levels of fullness, suggests poor ability to judge satiety (Rolls et al 2004)
larger portions increase intake short-term, also upper end ‘set point’ much weaker than lower so long-term has limited adjustment for increases in intake (Rolls 2006)
Portion size
larger portions encourage consumption past satiation, indicate socially appropriate amount to consume, adjust biological signals and cognitive perceptions over time
driven by primal instinct to consume as much as possible when available
children better at regulating and less affected by external cues
external cues can override how much we think we should eat
Overconsumption of fat
fat is highly palatable, can prolong flavour and enhance sensory experience
high energy density so not very satiating, may overeat
evolutionary to seek out foods high in fat, sugar, salt and energy density as satisfy biological drive to have necessary energy
passive overconsumption
tendency to consume constant weight of food regardless of macronutrient content (Saltzman 1997)
reducing overconsumption
food response inhibition training - aims to reduce desire and increase self-control
may reduce liking, portion sizes and consumption of no-go unhealthy foods (Lawrence et al 2015)
Palatability
hedonic component of food reward, results from central integrative process incorporating aspects of taste, physiological states and individuals associative history (Berridge 1996)
brain regions and taste and palatibility
prefrontal cortex, nucleus accumbens, parabrachial nucleus, VTA, amygdala
Factors of taste and palatibility
hypothalamic control not only thing associated with appetite, also texture, flavour, cross-modal sensory experiences, associated emotions and memories
informational appearance, rewarding ability, culture
Liking vs wanting
liking - affect, measured through pleasure responses
wanting - motivation, measured through incentive motivation in animals and desire to eat in humans
both may be decreased when in satiety (Finlayson et al 2007)
Role of liking vs wanting
explicit liking as food ingested may establish its value but implicit wanting plays a more significant role in maintaining consumption/promoting overconsumption (Finlayson et al 2007)
lesion studies show they activate different areas of the brain in animals (Berridge 1996)
in humans: liking - opioid and GAB systems (Cambridge et al 2013) wanting - dopaminergic neurotransmitters (Blundell & Hill 1992)
very hard to differentiate with self-report suggesting poor awareness of hedonic changes
Effects of variety
increasing variety in taste, texture, appearance and choice can increase food intake and linked to higher weight (Pliner et al 1980)
increasing variety into a meal increases intake (Shebherd 1989)
can undermine process of satiety and meal termination and promote increased consumption
may be evolutionary as can optimise nutrients
consuming low variety diet decreased long-term intake for military personal but not for students in a cafeteria (Hirsch et al 2005)
