NCT05399836

SSS and the Impact of Portion Size on Daily Energy Intake

Completed NA Last updated 10 January 2023

What this trial tests

NA trial testing Portion size manipulation in Diet, Healthy in 47 participants. Completed in 12 October 2022.

Timeline

30 May 2022

Primary endpoint
12 October 2022

12 October 2022

Quick facts

Lead sponsor	University of Liverpool
Phase	NA
Status	Completed
Study type	INTERVENTIONAL
Allocation	randomized
Design	crossover
Masking	single
Primary purpose	prevention
Enrollment	47
Start date	30 May 2022
Primary completion	12 October 2022
Estimated completion	12 October 2022
Sites	1 location across United Kingdom

Drugs / interventions tested

• Portion size manipulation

Conditions studied

• Diet, Healthy — all drugs for Diet, Healthy →
• Eating Behavior — all drugs for Eating Behavior →
• Obesity — all drugs for Obesity →

Sponsor

University of Liverpool

Who can join

18 and older, female only, with Diet, Healthy or Eating Behavior. Patients with the condition only — healthy volunteers not accepted.

Sponsor's own description

Reducing food portion size is a potential strategy to reduce energy intake. However, it remains unclear who is most susceptible to the portion size effect (PSE). There are just two studies which have examined the PSE in the context of socioeconomic position (SEP), with mixed findings. In an online trial the PSE on intended consumption of unhealthy snacks was 18-24% larger for participants of lower SEP compared to participants of higher SEP. However, in a recent laboratory study which examined the PSE on total daily energy intake, participants of lower SEP were no more susceptible to the influence of portion size on eating behaviour than participants of higher SEP. Further research is required to elucidate these divergent findings.

There is also an absence of evidence examining the moderating role of subjective social status (SSS) - an individual's perceived standing in society - on the PSE. Given evidence that the subjective experience of social class may be associated with health outcomes, the present study examines whether reductions to the portion size reduces daily energy intake, and whether and how SSS (higher vs lower) moderates the PSE.

In a crossover experiment, participants will be served all meals in the lab on two separate days, with the portion size of main components at breakfast, lunch and dinner manipulated (i.e. smaller on one day vs larger on the other day). All other foods offered are identical. Food intake from the portion-manipulated breakfast, lunch and dinner, as well as all other meal components (non-portion-manipulated sides, dessert, seconds, snacks, etc.) will be measured, to assess total daily energy intake (kcal).

Publications & conference data

2 peer-reviewed publications reference this trial (live from Europe PMC):

1. Socioeconomic position and the influence of food portion size on daily energy intake in adult females: two randomized controlled trials.
   Langfield T, Clarke K, Marty L, Jones A, et al · · 2023 · cited 10× · PMID 37101143 · DOI 10.1186/s12966-023-01453-x
2. Socioeconomic position and the influence of food portion size on daily energy intake in adult females: two randomized control trials
   Langfield T, Clarke K, Marty L, Jones A, et al · · 2022 · DOI 10.1101/2022.12.20.22283727