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Provision of Small vs. Large Portion Sizes and Later Food Intake

Provision of Small vs. Large Portion Sizes and Later Self-selected Food Intake: 3 Experimental Laboratory Studies in UK Participants

Status
Completed
Phases
NA
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT03241576
Enrollment
307
Registered
2017-08-07
Start date
2015-05-01
Completion date
2017-04-01
Last updated
2017-08-07

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Eating Behavior

Brief summary

In 3 laboratory experiments the effect that receiving a small vs. large portion size of food has on later intake of that food was examined

Detailed description

Historical increases in the size of commercially available food products have been linked to the emergence of a worldwide obesity crisis. Although the acute effect portion size has on food intake is well established, the effect that exposure to smaller portion sizes has on future portion size selection is yet to be examined.We tested whether reducing a food portion size may 'renormalize' perceptions of what constitutes a normal amount of food to eat and result in people selecting and consuming smaller portions of that food in future. Across three experiments participants were served a large or smaller portion of food. In experiments 1-2, twenty four hours later participants freely selected and consumed a portion of that food. In experiment 3, one week later participants reported on their preferred portion size of that food.

Interventions

BEHAVIORALSmall portion size provision

The intervention is the small meal size participants are provided with during a lunchtime session in the laboratory.

BEHAVIORALLarge portion size provision

The intervention is the large meal size participants are provided with during a lunchtime session in the laboratory.

Sponsors

University of Liverpool
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
BASIC_SCIENCE
Masking
NONE

Eligibility

Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes

Inclusion criteria

* 18 years or older

Exclusion criteria

* History of food allergy, eating disorder or currently dieting to lose weight

Design outcomes

Primary

MeasureTime frameDescription
Later food intake (24 hour)Measured 24 hours after random allocation (experiments 1 and 2)Amount of the lunchtime food later chosen and consumed
Later food intake (7 days)Measured 7 days after allocation (experiment 3)Amount of the lunchtime food later chosen and consumed

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 7, 2026