Lec 4 - Cognition and Dietary Behaviour Flashcards
Geier & Rozin et al 2006 pretzel study
Illustrate unit bias and portion size effect
People choose, and presumably eat, much greater weights of Tootsie Rolls and pretzels when offered a large as opposed to a small unit size (and given the option of taking as many units as they choose at no monetary cost).
-And consume substantially more M&M’s when the candies are offered with a large as opposed to a small spoon (again with no limits as to the number of spoonfuls to be taken).
=suggests that if more is available we tend to consume more
BUT they measured selection, rather than consumption. Also many individuals who took a whole pretzel might have preferred a half pretzel if they had been given a choice between whole and half pretzels.
Wansink study 2005
Examined whether visual cues related to portion size can influence intake volume without altering either estimated intake or satiation. The experiment was a between-subject design with two visibility levels:
1) an accurate visual cue of a food portion (normal bowl) vs.
2) a biased visual cue (self-refilling bowl - bowls slowly and imperceptibly refilled as their contents were consumed)
=Participants who were unknowingly eating from self-refilling bowls ate more soup than normal bowl condition.
=Despite consuming 73% more, they did not believe they had consumed more, and did not feel more sated than those eating from normal bowls.
= Has been referred to as mindless eating
Bellisle et al 2001 study
condition 1, subjects ate alone (baseline)
condition 2, subjects ate alone while listening to recorded instructions focusing on the sensory characteristics of the foods (attention)
condition 3, subjects ate alone while listening to a recorded detective story (distraction)
condition 4, a group of 4 subjects had lunch together. On all occasions, the same foods were presented and ingested ad libitum.
Found that out of four conditions, subjects ate the most in the distraction condition in which subjects ate alone while listening to a recorded detective story relative to eating alone, and eating alone while listening to recorded instructions focusing on the sensory characteristics of the foods (attention)
The difference in energy intake between the baseline and distraction conditions significantly correlated with cognitive restraint of the TFEQ. Suggesting that cognitive restraint exerts a quantifiable limiting effect on intake at meal times and this effect can be offset by cognitive distraction
Brunstrom and Mitchell 2006 study
pp ate while playing computer game or sat in silence
=distracted participants experienced smaller changes in their desire to eat and fullness/hunger
=distracted participants maintained a desire to eat all foods (regardless of whether they have already eaten them). This was evident 5 and 10 min after the eating episode had terminated. Non-distracted reported a reduction in their desire to eat the eaten food. SUGGESTS SPECIFIC SATIETY
Higgs 2002
Looked at unrestrained females in one of three conditions who were given fixed lunches to consume
=Merely being reminded of a recent eating episode is sufficient to decrease subsequent food intake in unrestrained eaters. This effect is specific to food eaten that day because thinking about food eaten the previous day does not inhibit intake.
Higgs and Woodward 2008
Using a repeated-measures design, women undergraduate students visited the laboratory to eat a fixed lunch either while watching television or in the absence of television. Intake of cookies at a tasting session later that afternoon was measured and participants recalled eating the lunch and rated the memory for vividness
=Participants ate significantly more cookies after they had eaten their lunch while watching television than when they had eaten their lunch while not watching television.
= Watching television while eating lunch was also associated with reduced vividness ratings of the memory of the lunch – eating in absence of tv had better memory
what is Hyperphagia and what is it often seen in?
It is overeating and seen in amnesic patients (who also have dysregulated eating)
Cecil, Francis study
investigated the contribution of oral, gastric and intestinal factors in the control of appetite, 425ml tomato soup was administered either orally, intragastrically (covertly and overtly) or intraduodenally (overtly). Ratings of fullness, hunger and desire to eat were recorded over a period of 2h
=In oral condition, soup produced the greatest suppression of appetite
=In covert, in the absence of any information hunger reduces a bit but nowhere near as much as in other two conditions
=In overt condition, when ppl are told that soup is inserted into stomach, this info about what we are eating has profound effect on hunger = this largely restores effects of hunger
Brunstrom et al 2011 - smoothie study
tested the hypothesis that ‘expected satiety’ plays a causal role in the satiety that is experienced after a food has been consumed.
Ppl consumed fruit smoothie, just before showed them large or small plate of fruit that was in smoothie.
Participants then assessed the expected satiety of the smoothie and provided appetite ratings, before, and for three hours after its consumption.
= participants reported significantly less hunger and significantly greater fullness in the large portion condition. Importantly, this effect endured throughout the test period (for three hours)
=thus beliefs and expectations can have marked effects on satiety and they show that this effect can persist well into the inter-meal interval.
Brunstrom et al 2012 -self-refilling soup study
in this study they isolated the extent to which memory for a recently consumed meal influences hunger and fullness over a three-hour period. Before lunch, half of pp were shown 300 ml of soup and half were shown 500 ml. Orthogonal to this, half consumed 300 ml and half consumed 500 ml.
=Immediately after lunch, self-reported hunger was influenced by the actual and not the perceived amount of soup consumed
= However, two and three hours after meal termination this pattern was reversed - hunger was predicted by the perceived amount and not the actual amount. Participants who thought they had consumed the larger 500-ml portion reported significantly less hunger. This was also associated with an increase in the ‘expected satiation’ of the soup 24-hours later. Memory therefore places an important role later on!
Morewedge et al study.. imagine..
Imagine…
Feeding 33 coins into laundry machine (0 repetitions)
Feeding 30 coins and eating 3 M&Ms (3 repetitions)
Feeding 3 coins and eating 30 M&Ms (30 repetitions)
When imagined consuming 30M&Ms - food intake was reduced. Argue that this represents a form of habituation.
de Castro study
Social influences on eating were investigated by paying adults to maintain 7-d diaries of everything they ingested, time, subjective hunger, and number of people present.
=Meals eaten with others contained more carbohydrate, fat, protein, and total calories.
= The number of people present was positively correlated with meal size even when meals eaten alone were excluded.
This suggests that social factors increase amounts eaten and disrupt postprandial regulation
de Castro concluded that social facilitation was the single most powerful influence on eating, and that “the number of people eating with the subject …is the best predictor of how much food an individual will consume”
Salvy 2007 - how do people adjust eating with others
examined how males and females adjust their level of eating as a function of their familiarity with and the gender of their eating companion, using a free-eating paradigm
=Findings indicated that both the familiarity between co-eaters and the participants’ gender predicted food consumption
ferriday et al 2015
Investigated whether eating a meal at a slow rate improves episodic memory for the meal and promotes satiety.
Participants consumed a 400 ml portion of tomato soup at either a fast or a slow rate. Appetite ratings were elicited at baseline and at the end of the meal (satiation). Satiety was assessed using; i) an ad libitum biscuit ‘taste test’ (3 h after the meal) and ii) appetite ratings (collected 2 h after the meal and after the ad libitum snack). To evaluate episodic memory for the meal, participants self-served the volume of soup that they believed they had consumed earlier (portion size memory) and completed a rating of memory ‘vividness’.
= Participants who consumed the soup slowly reported a greater increase in fullness
=However, we found little effect of eating rate on subsequent ad libitum snack intake.
=After 3 h, participants who ate the soup slowly remembered eating a larger portion but eating slowly did not affect ratings of memory vividness.
These findings show that eating slowly promotes self-reported satiation. For the first time, they also suggest that eating rate influences portion size memory. However little evidence was found for a relationship between episodic memory and satiety.
Boon et al. 2002
Distraction limits an individual’s capacity to monitor signals associated with satiety. Consistent with this idea, it has been suggested that normal dietary control requires access to a degree of ‘cognitive resource’
