HUNGER.2 +portion sizes

Question 1

THE SATIETY CASADE

Answer 1

Blundell 2010-

Question 2

expected satiety and expected satiation

Question 3

Portion sizes!

Answer 3

QUESTION- if we give people more food do they eat more?

previous- Van ittersam and watkins 2013- Geier, rozin, doros 2006- unit bias

Rolls, Morris & Roe (2002).
▫ +30% more energy for largest portions (1000g) compared- (people felt the same amount of fullness)
to the smallest (500g)
* Rolls et al., (2004).
▫ Replicated with sandwiches
▫ Gender differences- more in males
▫ Similar ratings of fullness
* Meta-analysis of 65 studies found that doubling the
portion served to individuals, increases food intake by
~35% (Zlatevska, Dubelaar & Holden, 2014)

Question 4

studies on plate cleaning

Answer 4

plate cleaning/ leftovers- different between normal weight and overweight individuals- Brownell et al., 1979- overweight women left less food on their plate (overweight are worse at regulating their intake?- more effected by external cue such as unit bias)

Question 5

why larger portion sizes mean we eat more?

Answer 5

• Larger portions:
  ▫ Encourage consumption past satiation
  ▫ Indicates socially appropriate amount to consume
  ▫ Adjust biological signals and cognitive perceptions over time about what portion
  elicits satiety
  ▫ Primal instincts to consume as much food as possible when available.
• Ability to regulate food intake changes as we age - children <3 better at regulating
  intake and less affected by external cues
• Experimental evidence indicates sig. impact on food intake in the short term; Similar
  effects in naturalistic settings
• Longitudinally - Limited adjustment for increases in intake (e.g., Rolls, 2006; Vermeer
  et al., 2011)
  ▫ The upper end ‘set point’ intervention to reduce intake is much weaker than the
  lower end intervention to increase intake.

Question 6

individual differences in portion size

Answer 6

Cunningham et al., 2023- looked at eating rate
Cunningham et al., (2023).
* Repeated measures over four weeks.
* Macaroni cheese served in 400g to 700g
portion sizes (increases by 100g)
* N = 44 (29 female)
* Explored how elements of eating microstructure (e.g., meal duration, bite count, mean bite size, and mean eating rate) were linked to portion size increases.

Faster eating rate and larger bite sizes were related to greater food consumption, but did not moderate the portion size effect (i.e. associated with greater consumption at all portion sizes)

Question 7

portion size effect pt2

Answer 7

Hetherington and Blundell 2018-
Looked at portion sizes of high energy dense foods (HEF). Portion size effect has been studied lots, showing if we increase protion sizes consumption also increases.

An obvious solution to the PSE is to ‘downsize’ HED meal items and snacks, but whether this strategy is acceptable or feasible is not clear. In adults, the effects of downsizing are mixed and for children and adolescents, as yet unclear. The contention is that for those who are still learning about social norms and appropriate portions, there remains the potential to counter the PSE through downsizing strategies.

Question 8

unit bias 2

Answer 8

Kerameas et al., 2015:
The “unit bias” has been proposed as an explanation for the portion-size effect; people consider a single unit to be an appropriate amount to eat and thus eat more when served a larger unit than when served a smaller unit. We suggest that the unit bias might be better characterized as a “segmentation effect,” such that people eat less when a unit of food is separated into smaller subunits, but may eat more than a single unit. Furthermore, we suggest that portion-size effects should be independent of this segmentation effect. Method: In Study 1, female participants (n = 87) were served either a small or large portion of food that was either presented in the form of a single unit or multiple individually wrapped units. In Study 2, female participants (n = 42) were served a fixed portion of food that was either presented in the form of a single unit or multiple units presented on separate plates. Results: Across both studies, there was no evidence that participants prefer to eat a single unit. Participants served multiple smaller units did eat less than did participants served a single larger unit, even when the overall portion size was the same, but the amount eaten was consistently more than a single unit. Furthermore, perceived norms of appropriate intake mediated the effect of unit number on food intake. Conclusions: These findings suggest that a segmentation effect, rather than a unit bias, is driving people’s food intake, with implications for designing interventions aimed at reducing excessive food intake.